Monkeys are a large and varied group of mammals of the primate order. They live in trees, grasslands, forests, mountains and plains. They are seriously threatened by habitat loss.
The term monkey includes all primates that do not belong to the categories human, ape, or prosimian; however, monkeys do have certain common features. All are excellent climbers, and most are primarily arboreal. Nearly all live in tropical or sub-tropical climates. Unlike most of the prosimians, or lower primates, they are almost all day-active animals. Their faces are usually flat and rather human in appearance, their eyes point forward, and they have stereoscopic color vision. Their hands and feet are highly developed for grasping; the big toes and, where present, the thumbs are opposable. Nearly all have flat nails. Monkeys habitually sit in an erect posture.
Monkeys are most easily distinguished from apes by their tails. Apes have no tails. Apes swing arm-to-arm in trees, but most monkeys don’t. Instead, they run across branches. Their skeletal structure is similar to that of other four-footed animals.
Monkeys live in troops of up to several hundred individuals and travel about in search of food, having no permanent shelter. As in apes and humans, the female has a monthly reproductive cycle, and mating may occur at any time, but in some species mating is seasonal. Usually only one infant is born at a time; it is cared for by the mother for a long period.
Monkeys have their own complex language, using different sounds to identify different types of predators. They have been witnessed banging stones together to warn each other of nearby predators. They also use facial expressions and body movements to communicate with each other. Grinning, yawning, head bobbing, jerking the head and shoulders forward or pulling the lip is usually a sign of aggression. Affection is expressed by grooming.
Some monkeys are monogamous, mating for life. They become distressed when separated. They express affection by holding hands, nuzzling, cuddling, grooming each other, intertwining their tails and lip smacking.
The pygmy marmoset is the smallest monkey in the world measuring less than six inches and weighing only three to five ounces. The male mandrill is the world's largest monkey at just over 3 feet long and weighing over 70 pounds.
Most monkeys eat both plants and animals. Some also eat dirt. Monkeys peel their bananas like humans and do not eat the skins.
Monkeys can grasp with both their fingers and toes. Many monkeys are skilled tool users. They use branches to capture food, use leaves as gloves, smash nuts with rocks, remove spines and hairs from caterpillars by rubbing them against branches and use large branches to club snakes.
There are two large groups, or superfamilies, of monkeys: Old World monkeys (Cercopithecoidea) and New World monkeys (Ceboidea).
OLD WORLD MONKEYS
The Old World monkeys are found in South Asia, with a few species as far North as Japan and North China, and in all of Africa except the deserts. Most are arboreal, but a few, such as baboons and some macaque species, are ground dwellers. Some Old World monkeys lack tails; when a tail is present it may be long or short but is never prehensile (grasping). The nostrils are close together and tend to point downward. Many species have cheek pouches for holding food, and many have thick pads (called ischial callosities), on the buttocks. Their gestation period is five to nine months. Adult Old World monkeys have 32 teeth. The Old World monkeys, sometimes called true monkeys, are more closely related to the apes and humans than they are to the New World monkeys; the two monkey groups probably evolved separately from ancestral primates.
The Old World monkeys include the many species of macaque, widely distributed throughout Africa and Asia. The rhesus monkey is an Asian macaque. Related to the macaques are the baboons of Africa and South West Asia, as well as the mandrill and mangabey of Africa. The guerezas, or colobus monkeys (genus Colobus), are very large, long-tailed, leaf-eating African monkeys. Their Asian relatives, the langurs and leaf monkeys, include the sacred monkeys of India. The snub-nosed monkey of China and the proboscis monkey of Borneo are langurlike monkeys with peculiar snouts. The guenons (Cercopithecus) are a large group of long-legged, long-tailed, omnivorous monkeys found throughout sub-Saharan Africa. One very widespread guenon species is the green monkey, or vervet, with olive-brown fur.
NEW WORLD MONKEYS
The New World monkeys are found from South Mexico to central South America, except in the high mountains, and are classified into two families (Callatrichids and Cebids). The Callatrichids are very small, while the Cebids are similar in size to the Old World monkeys. They are all thoroughly arboreal and most have long, prehensile tails with which they can manipulate objects and hang from branches. In most the thumb is lacking. They have widely separated nostrils that tend to point outward; they lack cheek pouches and ischial callosities (a thickened piece of skin found on the buttocks). Their gestation period is four to five months. Adults of most New World species have 36 teeth. The New World monkeys include the marmosets and tamarins, small monkeys with claws that are classified in a family of their own, the Callithricidae. The rest of the New World monkeys are classified in the family Cebidae. They include the capuchin (genus Cebus), commonly seen in captivity, which has a partially prehensile tail. Prehensile tails are found in the spider monkey and woolly monkey as well as in the howler monkey, the largest member of the family, which has a voice that carries several miles. Smaller forms with nonprehensile tails are the squirrel monkey and titi, the nocturnal douroucouli, or owl monkey, the saki, and the ouakari.
Thousands of primates are peddled as "pets" each year, including monkeys, apes and lemurs. Highly intelligent and social animals, they suffer terribly in the inhumane pet trade.
These wild animals are bred in captivity and taken from their mothers within hours or days of birth, or stolen from their mother in the wild who is often killed in the process. Sold like toys by unethical businesses and backyard breeders, profit is put above the welfare of the animals. Unprepared guardians purchase the animals, often with little knowledge on primate care. Adorable baby monkeys quickly grow into aggressive and territorial adults. Guardians often resort to drastic measures to control the animals, such as inhumane tooth removal. Eventually they are abandoned, given to roadside zoos or sold to another unprepared family where the cycle begins again. They end up living their lives in tiny cages, isolated, lonely, deprived of their wild nature and social interaction with their own kind.
The complex physical, psychological and social needs of primates can never be met when they are kept as pets. Living in constant frustration, these wild animals can inflict serious and catastrophic injuries. They can also spread diseases that are deadly to humans, including viral, bacterial, fungal and parasitic infections. It is common for monkeys to carry tuberculosis, hepatitis and simian herpes B.
Even the smallest of monkeys are incredibly strong and become unpredictable when they reach sexual maturity. Hundreds of people have been injured by attacks from primates, sometimes causing permanent disability and disfigurement. MONKEYS USED IN RESEARCH
Every year thousands of monkeys are imprisoned in laboratories, where they are abused, neglected and killed in invasive and painful experiments. They are either bred in government or commercial facilities or laboratories, or captured from the wild. Those born in laboratories are torn from their mothers usually within three days of birth. Those from the wild are often taken from their mothers, who are sometimes killed. They are crammed into tiny crates with little to no food or water and taken to filthy holding centers, followed by long and terrifying trips in the cargo holds of passenger airlines. Following the traumatic separation from their families and/or homes, monkeys in laboratories are usually confined to small, barren cages. They barely have enough room to sit, stand, lie down or turn around.
90 percent of primates in laboratories exhibit abnormal behaviors caused by the physical abuse, psychological stress, social isolation and barren confinement that they are forced to endure. Many go insane, rocking back and forth, pacing endlessly in the cages, and engaging in repetitive motions and acts of self-mutilation.
Their fundamental needs and desires are disregarded and they are subjected to painful and traumatic procedures. Most animal experiments are not relevant to human health and do not contribute meaningfully to medical advances. Human clinical and epidemiological studies, human tissue and cell-based research methods, cadavers, sophisticated high-fidelity human patient simulators and computational models are more reliable, more precise, less expensive and more humane than animal experiments.
MONKEYS IN THE ENTERTAINMENT INDUSTRY
The use of monkeys as “entertainers” removes animals from their natural habitat; depriving them of the ability to freely engage in instinctual behaviors. Both children and adults are desensitized to animal mistreatment by the animal entertainment industry. Whether they're at a zoo, on a film set, or under a circus tent, monkeys used as entertainment are forced to perform unnatural and painful tasks through abusive training methods.
Animals used in film, television, advertising or as sports mascots are ripped away from their mothers as infants. They are forced to spend most of their lives in small cages. They often live alone, resulting in severe psychological anxiety. “Performing” is stressful, confusing and often torturous. Training methods may involve beating the animals, causing them to be constantly anxious and fearful. When the animals become too large to handle, they are often dumped at shoddy roadside zoos and other substandard facilities, where they spend the rest of their lives in small, barren cages—many in solitary confinement. “Retirement” from entertainment is a long life of misery for these highly intelligent and sensitive animals. The American Humane Association’s (AHA) “No Animals Were Harmed” seal of approval is extremely misleading. AHA does not monitor living conditions of animals off set, during pre-production training, or during the premature separation of infants from their mothers.
Circus animals are forced to travel in box cars or trucks for months at a time with no regard for temperature, exercise or normal interaction with their own kind. These animals do not willingly stand on their heads, jump through rings of fire, or ride bicycles. They don’t perform these tricks because they want to and they don’t do any of these meaningless acts in their natural habitat. They do not perform because they are positively reinforced. Instead, they are trained with varying levels of punishment, neglect and deprivation.
Even under the best of circumstances, captivity is cruel for wild animals. Confined to tiny areas and gawked at by crowds, animals in exhibits and acts endure constant stress. They may suffer from temperature extremes and irregular feeding and watering. Without exercise, they become listless, their immune systems are weakened, and they become prone to sickness; many resort to self-mutilation in reaction to stress or boredom. Mental illness is rampant among confined animals. Torn from their families and deprived of all dignity, every part of their lives is controlled by their captors.
While zoos may appear to be educational and conservation-oriented, most are designed with the needs and desires of the visitors in mind, not the needs of the animals. Many animals in zoos exhibit abnormal behavior as a result of being deprived of their natural environments and social structures. When the facility breeds too many animals they become "surplus" and often are sold to laboratories, traveling shows, shooting ranches, or to private individuals who may be unqualified to care for them.
Seahorses are marine fish belonging to the genus Hippocampus of the family Syngnathidae. They are found in temperate and tropical waters all over the world.
Seahorses range in size from 16 mm to 35 cm. They are notable for being the only species where the males get pregnant.
The seahorse is a true fish, with a dorsal fin located on the lower body and pectoral fins located on the head near their gills. Some species of seahorse are partly transparent.
Sea dragons are close relatives of seahorses but have bigger bodies and leaf-like appendages which enable them to hide among floating seaweed or kelp beds. Sea dragons feed on larval fishes and amphipods, such as small shrimp-like crustaceans called mysids (sea lice), sucking up their prey with their small mouths. Many of these amphipods feed on red algae that thrives in the shade of the kelp forests where the sea dragons live.
Seahorses reproduce in an unusual way: the male becomes pregnant. Most seahorse species pregnancies last approximately two to three weeks.
The male seahorse has a brood pouch where he carries eggs deposited by the female. The mating pair entwines their tails and the female aligns a long tube, called ovipositor, with the male's pouch. The eggs move through the tube into the male's pouch where he then fertilizes them. The embryos will develop between ten days and six weeks, depending on species and water conditions. When the male gives birth, he pumps his tail until the baby seahorses emerge.
The males pouch regulates salinity for the eggs, slowly increasing in the pouch to match the water outside as the eggs mature. Once the offspring hatch, the male releases them and is done caring for them.
Once released, the offspring are independent of their parents. Some spend time among the ocean plankton developing before settling down and hitching as their parents do. Other species (H. zosterae) hitch immediately and begin life in the benthos.
Seahorses are frequently monogamous, though several species (H. zosterae and H. abdominalis) are highly gregarious. In monogamous pairs, the male and female will greet one another with courtship displays in the morning, and in the evening to reinforce their pair bond. They spend the rest of the day separate from each other hunting for food.
THREATS TO SEAHORSES
Seahorse populations have been endangered in recent years by overfishing. The seahorse is used in traditional Chinese herbology, and as many as 20 million seahorses may be caught each year and sold for this purpose.
Import and export of seahorses is controlled under CITES since May 15, 2004.
The fastest land animal in the world, the cheetah is a marvel of evolution. Capable of running up to 70 miles per hour, the cheetah’s slender, long-legged body is built for speed. Its spotted coat, small head and ears, and distinctive "tear stripes" from the corner of the eyes down the sides of the nose make the cheetah highly recognizable among the large cats of Africa.
The cheetah is smaller than other big cats, measuring 44 to 53 inches long with a tail length of 26 to 33 inches. Cheetahs usually weigh 110 to 140 pounds. An estimated 9,000 to 12,000 cheetahs remain in the wild. They live an average of 10 to 12 years. Once found throughout Africa and Asia, cheetahs are now confined to parts of eastern and southwestern Africa.
Cheetahs thrive in areas with vast expanses of land where prey is abundant. In Namibia cheetahs have been found in a variety of habitats, including grasslands, savannahs, dense vegetation, and mountainous terrain. Ninety five percent live on commercial farms. Cheetahs are found in the wild primarily in Africa, but in the past their range extended into northern and southern India. Conservationists using camera traps have recently discovered surviving populations in Iran and are taking steps to protect them. In much of their former range they were domesticated by aristocrats and used to hunt antelopes in much the same way as is still done with members of the greyhound group of dogs. Aside from an estimated 200 cheetahs living in Iran (Khorasan Province), the distribution of cheetahs is now limited to Africa. There are 5 subspecies of cheetah in the genus Acinonyx: four in Africa and one in Iran. The endangered subspecies Acinonyx jubatus venaticus lives in Asia (Iran). In 1990, there were reports in the Times of India of a cheetah sighting in eastern India. There is a chance some cheetahs remain in India, though it is doubtful. There have also been reports of Asiatic cheetahs in the Balochistan Province of Pakistan, though these continue to be unverified. The cheetah prefers to live in an open biotope, such as semi desert, prairie, and thick brush.
Cheetahs rely on a burst of speed to catch such swift prey as gazelles, wildebeest calves, impalas and smaller hoofed animals, knocking their prey to the ground and delivering a suffocating bite to the neck. They must eat quickly to avoid losing their kill to other carnivores.
Cheetahs are typically solitary creatures. Females raise their cubs for about a year. Males sometimes live with a small group of brothers from the same litter. Cheetahs hunt in late mornings and early evenings. Chases last from 20 to 60 seconds. Only half are successful. Cheetahs reach sexual maturity in 20 to 24 months. Mating season is throughout the year. The cheetah can live over twenty years, but their life is often short, for they lose their speed with old age. Unlike other felines, the adult females do not have true territories and seem to avoid each other, though some mother/daughter pairs have been known to continue for small periods of time. Cheetahs have a unique, well structured social order. Females live alone except when they are raising cubs. The females raise the cubs on their own. The first 18 months of a cub's life are important; cubs learn many lessons because survival depends on knowing how to hunt wild prey species and avoid other predators such as leopards, lions, hyenas, and baboons. At 18 months, the mother leaves the cubs, which then form a sibling group, that will stay together for another 6 months. At about 2 years, the female siblings leave the group, and the young males remain together for life. Males live alone or in coalitions made up of brothers from the same litter. Some coalitions maintain territories in order to find females with which they will mate. Territories are often located in areas where there is a rich supply of wild game and/or water. Fierce fights between male coalitions, resulting in serious injury or death, can occur when defending territories. Coalitions of many male cheetahs are much more successful at winning and keeping territories than the ones who live alone. Life span is up to 12 years in wild.
Two to four cubs are born to a litter. Cubs are smoky grey in color with long wooly hair, called a mantle, running along their backs. This mantle is thought to help camouflage cubs in grass, concealing them from predators. Mothers move cubs to new hiding places every few days. At five to six weeks, cubs follow the mother and begin eating from her kills. Cubs stay with their mother for about a year.
THREATS TO CHEETAHS
The future of the cheetah is doubtful because of increasing loss of habitat, declines in prey, high cub mortality rates and conflict with ranchers. Cheetah fur was formerly regarded as a status symbol.
Today, cheetahs have a growing economic importance for ecotourism and they are also found in zoos, denied their wild nature, strong family bonds and natural social interactions. Like all captive wildlife, they face constant stress and are denied their wild nature and social structures. The needs and desires of humans comes before the needs of the animals in the animal entertainment industry.
Because cheetahs are far less aggressive than other big cats, kittens are sometimes sold as pets. This is an illegal trade, because international conventions forbid private ownership of wild animals or species threatened with extinction. Their complex physical, psychological and social needs can never be met when they are kept as pets.
Cheetahs were formerly, and are sometimes still, hunted because many farmers believe that they eat livestock. When the species came under threat, numerous campaigns were launched to try to educate farmers and encourage them to conserve cheetahs. Recent evidence has shown that if cheetahs can avoid it they will not attack and eat livestock, preferring their wild prey. However, they have no problem with including farmland as part of their territory, leading to conflict.
Cheetah cubs have a high mortality rate due to genetic factors and predation by carnivores in competition with the cheetah, such as the lion and hyena. Some biologists now believe that they are too inbred to flourish as a species.
The cougar (Puma concolor), also commonly known as the mountain lion, puma, or catamount, is a large felid of the subfamily Felinae native to the Americas. Its range, from the Canadian Yukon to the southern Andes of South America, is the greatest of any large wild terrestrial mammal in the Western Hemisphere. An adaptable, generalist species, the cougar is found in most American habitat types. It is the second heaviest cat in the New World, after the jaguar. The cougar is more closely related to smaller felines, including the domestic cat, than to any subspecies of lion, of which only the jaguar is native to the Western Hemisphere.
The cougar is an ambush predator and pursues a wide variety of prey. Primary food sources are ungulates, which include deer, such as mule deer, white-tailed deer, elk, and moose. Other ungulates it preys on are bighorn sheep, as well as domestic cattle, horses and sheep, particularly in the northern part of its range. Cougars will also hunt species as small as insects and rodents.
This cat prefers habitats with dense underbrush and rocky areas for stalking, but can also live in open areas. The cougar is territorial and survives at low population densities. Individual territory sizes depend on terrain, vegetation, and abundance of prey. While large, it is not always the apex predator in its range, yielding to the jaguar, gray wolf, American black bear, and grizzly bear. It is reclusive and mostly avoids people.
Female cougars reach sexual maturity between one-and-a-half to three years of age. They typically average one litter every two to three years throughout their reproductive lives, though the period can be as short as one year. Females are in estrus for about 8 days of a 23-day cycle; the gestation period is approximately 91 days. Females are sometimes reported as monogamous. Copulation is brief but frequent.
Only females are involved in parenting. Female cougars are fiercely protective of their cubs, and have been seen to successfully fight off animals as large as American black bears in their defense. Litter size is between one and six cubs; typically two. Caves and other alcoves that offer protection are used as litter dens. Born blind, cubs are completely dependent on their mother at first, and begin to be weaned at around three months of age. As they grow, they begin to go out on forays with their mother, first visiting kill sites, and after six months beginning to hunt small prey on their own. When cougars are born they have spots, but they lose them by the age of 2 1/2 years.
Young adults leave their mother to attempt to establish their own territory at around two years of age and sometimes earlier; males tend to leave sooner. Life expectancy is reported at eight to 13 years, though they have been known to live as long as 30 years. Causes of death in the wild include disability and disease, competition with other cougars, starvation, accidents, and, where allowed, human hunting. Feline immunodeficiency virus, an endemic HIV-like virus in cats, is well-adapted to the cougar.
Like almost all cats, the cougar is a solitary animal. Only mothers and kittens live in groups, with adults meeting only to mate. They are secretive and crepuscular, being most active around dawn and dusk. Estimates of territory sizes vary greatly, from 10 to 386 square miles, with female ranges half the size of males. Male ranges may include or overlap with those of females but, at least where studied, not with those of other males, which serves to reduce conflict between cougars. Ranges of females may overlap slightly with each other. Scrape marks, urine, and feces are used to mark territory and attract mates. Males may scrape together a small pile of leaves and grasses and then urinate on it as a way of marking territory. Home range sizes and overall cougar abundance depend on terrain, vegetation, and prey abundance.
Because males disperse farther than females and compete more directly for mates and territory, they are most likely to be involved in conflict. Where a subadult fails to leave his maternal range, for example, he may be killed by his father. When males encounter each other, they hiss, spit, and may engage in violent conflict if neither backs down.
THREATS TO COUGARS
Conservation threats to the species include persecution as a pest animal, environmental degradation and habitat fragmentation, and depletion of their prey base. Wildlife corridors and sufficient range areas are critical to the sustainability of cougar populations.
The cougar's total breeding population is estimated at less than 50,000 by the IUCN, with a declining trend. Prolific hunting following European colonization of the Americas and the ongoing human development of cougar habitat has caused populations to drop in most parts of its historical range. In particular, the cougar was extirpated in eastern North America in the beginning of the 20th century, except for an isolated Florida panther subpopulation. However, in recent decades, breeding populations have moved east into the far western parts of the Dakotas, Nebraska, and Oklahoma. Transient males have been verified in Minnesota, Missouri, Wisconsin, Iowa, the Upper Peninsula of Michigan, and Illinois. They have been observed as far east as coastal Connecticut. Eastern cougars (Puma concolor cougar) are commonly sighted, despite being declared extirpated in 2011.
Cougar hunting is prohibited in Argentina, Brazil, Bolivia, Chile, Colombia, Costa Rica, French Guiana, Guatemala, Honduras, Nicaragua, Panama, Paraguay, Suriname, Venezuela, and Uruguay. The cat has no reported legal protection in Ecuador, El Salvador, and Guyana. Regulated cougar hunting is still common in the United States and Canada, although they are protected from all hunting in the Yukon; it is permitted in every U.S. state from the Rocky Mountains to the Pacific Ocean. Mountain lions may be killed in California if “a depredation permit is issued to take a specific lion killing livestock or pets; to preserve public safety; or to protect listed bighorn sheep.” Texas is the only state in the United States with a viable population of cougars that does not protect that population in some way. In Texas, cougars are listed as “nuisance wildlife” and any person holding a hunting or a trapping permit can kill a cougar regardless of the season, number killed, sex or age of the animal.
Moose, the largest member of the deer family, are found in the northern parts of Eurasia and North America. The Eurasian species, A. alces, is known in Europe as the elk, a name which in North America is applied to another large deer, the wapiti. The Eurasian and the American moose are quite similar, but the American moose is somewhat larger and is considered by some to be a separate species, A. americana. It inhabits the coniferous forests of Canada and the northern United States. The Eurasian moose is found from Scandinavia to E Siberia.
Moose have a heavy brown body with humped shoulders, and long, lighter-colored legs; the front pair longer than the hind legs. They have a thick, overhanging, almost trunk like muzzle and a short neck. A flap of skin covered with long hair, the bell, hangs from their throats. Males have broad, extremely flattened antlers, with a spread of up to 6 feet. The largest variety is the Alaska moose; the adult male weighs from 1,000 to 1,800 pounds and stands as much as 71⁄2 feet high at the shoulder.
Browsers rather than grazers, moose eat leaves, twigs, buds, and the bark of some woody plants, as well as lichens, aquatic plants, and some of the taller herbaceous land plants. Moose live in small groups during the summer, sometimes forming large herds in the winter. They are polygamous, the males becoming aggressive during the mating season. They are strong swimmers, reportedly crossing lakes many miles wide.
Although moose are generally timid, the males become very bold during the autumn breeding season; it is not uncommon for them to charge at moving trains. The females utter a loud call, similar to the lowing of cattle. During breeding (the rut), males will compete for females by fighting with their antlers and hoofs and by fierce clashing of antlers. As well as bellowing, the female moose emits a strong, odoriferous pheromone in order to attract a mate.
Females may begin to breed at 2, but more usually, 3 years of age. The mother gives birth to one, or occasionally two, calves in spring. The gestation period for a moose is about 216 to 240 days. Moose calves grow very quickly, nourished by their mother's milk, which is very high in fat and other nutrients. Females can be extremely protective of their young.
In North America, during the winter, moose may form loose aggregations in fairly dense conifer forests, which they keep open by trampling the snow. In the spring, moose can often be seen in drainage ditches at the side of roads, taking advantage of road salt which has run off the road. These minerals replace electrolytes missing from their winter diet.
The lifespan of a moose in the wild is roughly 15 to 25 years.
THREATS TO MOOSE
In North America, changes in land use patterns, mainly the clearing of northern forests for settlement and agriculture, have led to the range of the white tailed deer expanding northward. Where their ranges overlap, moose may become infected by parasites carried by the deer such as brain worm, Parelaphostrongylus tenuis and winter ticks, Dermacentor albipictus, which, though fairly harmless to deer, can be fatal to moose.
Ticks are threatening moose populations. Thousands of ticks can infest a single moose, causing anemia and death. In an attempt to rid themselves of ticks, moose rub off patches of their fur, leaving them more vulnerable to cold winter temperatures. Changes in climate may also threaten moose.
Protection in national parks and reserves in Canada and the United States has saved the moose from extermination. However, hunting and habitat degradation remain major threats to moose. Moose once lived throughout most of the United States and Canada, but the species population dwindled from hunting and land development. Moose are known to visit residential areas in search of food, and motorists occasionally collide with them. Hundreds of moose calves are orphaned every year due to the death of their mothers.
Government mismanagement is another threat to moose. Wildlife management agencies, rather than working to preserve ecosystems, often manage wildlife purely for human recreation. Moose are viewed as a "resource" to be conserved simply for recreational purposes. Left unaltered, the delicate balance of ecosystems is maintained by nature with predators reducing the sickest and weakest individuals.
Although ‘melonhead’ and ‘sea canary’ may be some common nicknames for this unique ocean dweller, the beluga is most commonly referred to as the white whale. Belonging to the family Monodontidae, the beluga’s only other family member is the narwhal, and their appearance and physiology is a result of being adapted to life in the cold waters of the Arctic. Beluga populations are also found in the seas and coastal areas around Russia, Greenland and North America, though many do migrate from the Arctic ice cap to warmer estuaries and coastal waters during the summer.
Belugas are some of the most easily recognized ocean mammals; they’re entirely white and have a distinctive bulge at the front of their heads called a melon. Unlike dolphins, belugas don’t possess a dorsal fin. Reaching maturity at around 10 years of age, male belugas can reach 18 feet long and weigh up to 3,500 lb, while females are generally smaller, growing up to 13.5 feet in length and weighing as much as 2,600 lbs. Between 40% and 50% of their body weight is actually blubber (fat), providing excellent insulation from frigid Arctic water; in fact, they have the highest blubber percentage of any whale. Their body shape is stocky and rounded, with broad, short flippers and a curved tailfin.
The beluga’s coloration is actually a camouflage technique, allowing them to blend in with the ice to escape detection by their predators, which are mainly polar bears and orcas. Calves are born dark grey, and progressively lighten over the next 7 years as they mature.
Belugas are also the only marine mammal that shed their skin; during the winter, their outer epidermal (skin) layer becomes thicker and more yellowish, but during the summer, they rub themselves on riverbed gravel to remove the extra layer.
The anatomy of a beluga’s head is distinctive among other ocean dwelling mammals. The neck vertebrae are not fused, allowing them to move their head from side to side without needing to rotate their entire body; this helps when hunting prey and gives them better maneuverability in deeper water. Their beak (called a rostrum) has around 40 small, blunt teeth that are used to catch prey, and they have a single blowhole on the top of their head.
A beluga’s melon is extremely essential to its ability to accurately move through its ocean home and hunt. Their melon is a prominent bulge at the front of their head that contains an organ used for echolocation and communication. A beluga can actually focus the sounds they emit by changing the shape of its head. Belugas also use their head, along with their dorsal ridge, to help open up small holes in the ice through which they can breathe.
Belugas are the lazy divers of the whale world, typically not diving any deeper than about 20 m (66 feet), and they usually prefer to swim only at a depth that covers their bodies. They can stay underwater for 10-15 minutes, though a usual dive is usually much shorter than that, lasting around 3-5 minutes, and their heartbeat slows to between 12 and 20 beats per minute during a dive. They don’t jump out of the water like dolphins or killer whale relatives, and are slower swimmers too, being rather less aerodynamic marine mammals.
These beautiful whales have a very developed sense of hearing, which is also necessary for echolocation. They receive sound waves through their lower jaw, which are then transmitted towards their middle ear, and they can hear sounds within the range of 1.2 kHz to 120 kHz; to compare, we humans only have an average hearing range between 0.02 to 20 kHz. Their vision isn’t quite as spectacular, though they are able to see in and outside of water, and it’s likely that they can see some colors, since their retinas (surface covering the back of their eyes) contains cones. These ocean dwellers have no sense of smell, however.
Like other whales, belugas are very sociable and form small family groups called pods that can number anywhere from 2 to 25 members. They communicate with each other using whistles, trills and squawks, and their sounds are sometimes of such high frequency that they sound like birdsong. A pod is usually led by one male, but it’s not unusual for individual members to move from pod to pod.
Belugas seek out frequent physical contact with each other, they hunt in coordinated groups together, and they play chase and stage mock fights. They tend to be curious and investigative as well, often approaching humans in wild settings, swimming along boats, and playing with objects that they find in the water.
The type of diet that a beluga eats depends on the region in which they live and the season of the year. A typical diet is made up mainly of fish like cod, halibut, and Pacific salmon, as well as invertebrates like shrimp, squid, octopus, clams and sea snails. They search for food on the ocean floor or join with a group of other belugas to herd fish onto more shallow shoals.
Belugas reach breeding maturity by about four years of age, and females tend to birth one calf every three years or so. It’s not known if belugas can delay implantation of a fertilized egg, but gestation times can vary so greatly (anywhere from 12 to 15. 8 months after mating). Calves are born in warmer waters around bays or estuaries, and can swim by their mother’s side from birth, nursing every hour and staying dependent on her for the first year.
THREATS TO BELUGAS
Although polar bears and killer whales are the beluga’s only natural threats, these whales are also affected by water pollution and hunt-to-capture expeditions which provide whales for marine exhibits worldwide.
Whaling by European and American whalers in the 18th and 19th centuries severely affected beluga populations, as they were hunted for meat, blubber, and oil from their melons. Belugas make easy prey because of a predictable migration pattern. Indigenous populations in the Canadian, Alaskan and Russian Arctic regions still hunt belugas for food and skin.
Belugas are listed as ‘near threatened’ by the IUCN, and are protected under the Marine Mammal Act in the USA.
Jackals are medium sized members of the canine family. There are four main species of jackal: the side-striped jackal, the golden jackal, the black-backed jackal and the Ethiopian wolf jackal.
Jackals vary in color and size. They have golden, rust or silver-colored black fur and bushy tails. Jackals inhabit deserts, grasslands, savannas, marshes, mountains, bush-lands and woodlands. The golden jackal inhabits open deserts, savannas and arid grasslands. The side-striped jackal lives in moist savannas, marshes, mountains and bushlands. The black-backed jackal, or sliver-backed jackal, is found primarily in woodlands and savannas.
Jackals are opportunistic omnivores. They eat mostly a carnivorous diet and have adapted to hunting small mammals, reptiles and birds. Being opportunistic feeders, they eat whatever is available. Some species of jackal eat poisonous snakes. Jackals also scavenge the remains of carcasses killed by other larger predators. Many jackals, especially those in the tropics of Southeast Asia, also eat plants.
Jackals are usually nocturnal mammals, active at night. Some jackals in remote areas are more diurnal, active during the cooler times of the day. Jackals sleep in crevices in rocks and dens made by other animals. Jackals are fast running predators and can run for long periods.
Jackals live singly or in pairs, or in tribes called packs. 10 to 30 jackals can reside in a pack. Jackal community members work together to protect each other. Jackals who live in packs often hunt alone or with only one other jackal. Fewer jackals hunting together increases the chance of ambushing prey as they can be more stealthy and silent.
Jackals are territorial and defend their marked territories. Using a wide range of vocal sounds specific to each jackal family, they successfully keep other jackals away from their community. It is uncommon for jackals of other tribes to enter the territory. Verbal communication among jackals includes yips, howls, growls and owl-like hoots. Yipping calls are made when the family gathers. A siren-like howl is used to announce a food source has been found. Only family members respond to their own family's calls – ignoring the calls of other jackals.
Jackal mating season varies based on their location. African jackal mating season occurs in October. Southeast Europe jackal mating season takes place in December. Jackals in India mate throughout the year. Jackals are monogamous, mating for life. The gestation period lasts about 2 months. Typically 2 to 4 babies are born, but litters can be up to 9 cubs. Jackal babies are kept in underground dens, caves or rock crevices. Jackal mothers move the location of the den about every two weeks to prevent predators from finding the babies. Jackal babies are blind the first 10 days. They feed on their mother's milk and regurgitated meat provided by family members for the first couple of months. By the age of 6 months, young jackals are taught to hunt. Older pups help to take care of younger jackal babies.
Jackals are preyed upon by leopards, hyenas and eagles. Jackal babies are an easy target of eagles.
Jackals live up to 9 years in the wild.
THREATS TO JACKALS
Some jackals are endangered due to habitat loss, animal agriculture and hunting. As jackal habitats are lost, jackals increasingly infringe on human settlements where they can be viewed as a threat to livestock and poultry and are killed as pests.
A symbol of the wild west, the American bison is the heaviest land mammal in North America. Also called the American buffalo, the bison has a large head with relatively small, curving horns. It has a shaggy coat of brown hair on its shoulders and legs, while its body has shorter, finer hair. Bison are 5 to 6½ feet long and weigh 900 to 2,200 pounds. Males are larger than females on average.
Historically, bison numbered an estimated 20 million to 30 million. Today, approximately 250,000 remain in the United States. Of those, only 16,000 roam in the wild. Yellowstone National Park has the only population of free-roaming bison.
Bison typically live between 12 to 15 years and inhabit the Great Plains, prairies and forests. Bison eat grasses and sedges, moving continuously as they eat so that they rarely overgraze an area.
Bison live in herds of 20 to 50 animals. The females, or cows, lead family groups. Bulls (males) remain either solitary or in small groups for most of the year. Bison travel as a group and roam great distances in the wild. They can reach speeds of up to 30 mph.
Females produce one calf after a gestation period of nine and a half months. Calves are born in late April to mid-May. The cow protects the young. The offspring may remain with the mother for as long as three years after birth.
THREATS TO BISON
Shooting bison for their hides was a favorite frontier sport in the 19th century. Hunters practically eliminated the bison by 1890. In 1893, the first efforts were made to protect the animals. Today, the bison of Yellowstone National Park face the threat of slaughter when they exit the park and enter the state of Montana.
Along with the bald eagle, the bison perhaps best symbolizes the spirit of American wilderness. While many people are aware that both animals teetered on the brink of extinction in the past due to human encroachment, few realize that wild bison continue to be the victims of a calculated, annual slaughter in the Greater Yellowstone Area.
During the mid to late 1800s, government agents orchestrated one of the most aggressive and wanton animal massacres in history, killing bison indiscriminately in an attempt to subjugate Native Americans. With the addition of market hunters and settlers killing bison for profit and for fun, America's wild bison herds were reduced from an estimated 60 million to perhaps as few as 100. With the establishment of Yellowstone National Park in 1872 and the National Park Service in 1916, the 25 bison remaining in the Park finally were afforded some protection. Initially, management policies allowed for the active manipulation of populations by culling what was perceived as "surplus" animals. But eventually, the management strategy evolved to an approach which permitted natural regulation to occur, for the most part letting nature take its course rather than relying on human intervention.
This was good news for the bison, but sadly their fortune was short lived. Since the mid 1980s, more than 3,000 bison have been massacred under the supervision of government officials bowing to the pressures of the livestock industry and its cohorts. The livestock industry and federal and state livestock agencies contend that bison can transmit the Brucella abortus bacteria to cattle under natural conditions. In reality, there has never been a documented case of this occurring. Despite this fact, they continue to wage a war against Yellowstone bison.
In 1917, officials discovered that some Yellowstone bison were infected with Brucella abortus, the bacteria which causes the disease brucellosis in domestic cattle. In cattle, the disease produces spontaneous abortions, but bison do not appear to be similarly affected. In fact, over the past 80 years in the entire Greater Yellowstone Area, there have been only four documented bison abortions, which may or may not have been caused by the bacteria.
Over the past decade, bison have been emigrating from the Park over its northern and western boundaries into the state of Montana during winter months. Because of several mild winters, and the National Park Service's continued grooming of snowmobile trails which makes it easier for bison to exit the Park, more and more bison have been stepping hoof over Park boundaries.
The U.S. Forest Service issues grazing permits on lands adjoining Yellowstone National Park, generally for the months of June through October. Cattle grazing is even allowed in Grand Teton National Park. The interests of wildlife, and not cattle, should take precedence on public lands. The grazing allotments should be either closed or modified to minimize any contact between bison and cattle. Also, mandatory vaccination of domestic calves against brucellosis within the counties surrounding the Park could further reduce the risk, if any risk exits at all, of infection. Currently, vaccinations are not mandatory in Montana or Wyoming.
In addition to bison, elk can also be infected with the bacteria and can carry the disease. With more than 90,000 elk in the Greater Yellowstone Area, the likelihood of eliminating the bacteria using available technologies is virtually nonexistent. Moreover, if all infected bison were destroyed, exposure to elk would result in reinfection in the remainder.
This is particularly a problem in Wyoming where over 23,000 elk congregate on artificial feedgrounds, creating prime conditions for bacteria transmission. In fact, bison from Grand Teton National Park, just south of Yellowstone, have discovered the "free meals" being provided on the National Elk Refuge each winter in the Jackson Hole area. It is speculated that this herd of bison contracted the bacteria from elk on the feedground.
State officials rarely admit that elk may also carry the disease. Elk, of course, are a prime money maker for Montana and Wyoming state officials, who encourage propagation of elk herds so they can profit from the sale of sport hunting licenses.
Ironically, bison are being targeted allegedly to protect the livestock industry, but the general consensus among scientists is that cattle probably introduced the bacteria into the Yellowstone bison herd shortly before 1917.
Many-tentacled creatures that belong to the order Teuthida, squid are fascinating ocean dwellers, even achieving mythical status in our minds when we think of certain species like the giant squid. This order of molluscs, which is made up of approximately 300 recorded species so far, is similar to octopi and cuttlefish in that they have a distinct head, a symmetrical body structure, a mantle, eight arms, and phenomenal swimming abilities.
Squid are different from their ancestors and many other molluscs, however. In squid, the typical mollusc ‘foot’ structure has evolved. Squid usually have 8 paired smaller arms and two longer tentacles, and highly developed sensory organs. They also have a soft mantle enclosing their organ structure instead of a shell, although they do have a vestigial horny plate (called a gladius) still present that supports the mantle and acts as a site for muscle attachment.
Squid live across an enormous variety of aquatic habitats; an important food source for many other aquatic creatures. They can be found in both freshwater and saltwater environments, deep water and shallow water, and in many different temperature ranges. Most squid species tend to be no larger than about 24 inches long, but the giant squid may be as long as 43 feet in length. That’s almost the size of a school bus.
The squid’s appearance itself is certainly unique. Their skin is covered in chromatophores, which are special cells that allow the squid to change color in order to blend in with its surroundings, much like an octopus does. The mantle cavity contains the squid’s gills, organ systems, and siphon apparatus.
Although squid do have swimming fins, most squid species actually propel themselves mainly by jet propulsion by sucking water into the mantle cavity and pushing it forcefully out through the siphon.
Because they’re the ideal food for a number of predators ranging from sharks, fish, birds and whales, squid have evolved to be quick escape artists. If a squid is threatened, they can quickly expel ink from a small sac near their rectum, temporarily confusing their potential predator and providing cover for a quick escape. Some squid species will even propel themselves right out of the water to escape predators like schools of tuna, gliding through the air for short periods of time.
When they’re not being chased as a potential food source, squid are fairly effective hunters themselves, with fairly complex digestive systems. More intelligent than many of us would expect, some squid even hunt together cooperatively. A squid can propel itself with speedy precision towards its prey, first using a sharp, horny beak to kill prey and tear it into pieces, then pushing food from its muscular stomach into an organ called the caecum for digestion. Food then passes to the liver for nutrients to be absorbed before the squid expels the remaining waste.
Another anatomical feature characteristic to squid is the fact that they have three hearts; two to feed the gills, and a larger, systemic heart to pump blood around the squid’s body. Squid also have the largest eyes in the animal kingdom, relatively speaking. Positioned on either side of their head, a squid’s eyes focus by changing the position of the hard lens inside the eye, much how the lens of a camera moves back and forth.
Reproduction in squid takes place though the fertilization of the female’s eggs by the male. A male squid will often display unique color patterns to attract a female’s attention. Then he mates with her by inserting a copulatory pad (found on the modified end of one of his tentacles) into the female’s mantle and depositing spermatophores (sperm cells) that fertilize the eggs. The female will then place hundreds of eggs into a capsule, anchoring the capsule to sandy ocean bottoms. The time between laying and hatching of the eggs can be vary, since eggs laid in warmer water temperatures tend to hatch more quickly. Some squid egg beds can even cover acres of sand bed.
After the squid larvae hatch, they begin to feed on copepods and other plankton until they’re mature enough to hunt, though many are eaten by predators. Neither squid parent tends to the eggs or young, and it’s been noted that many adult squid species die shortly after reproducing, as an adult squid’s digestive organs diminish as they mature, making more room for reproductive organs. Most species haven’t been found to live longer than one or two years.
THREATS TO SQUID
The fact that squid reproduce rapidly and in large numbers is to their advantage. Squid can quickly replenish their population numbers, which is important to other species that rely on them as a food source.
Although there are no significantly endangered squid species at this point, the largest threat to squid populations worldwide is commercial overfishing by humans. Not only are they often used as bait to catch larger fish, but calamari (fried squid) is a popular dish in many places.
Water pollution, overharvesting and interference with egg capsules can also pose a potential threat to these animals as well.
Clams are invertebrates. Invertebrates are animals that do not have a backbone. Clams belong to a group of invertebrates called mollusks. There are over 100,000 kinds of animals or species in the Mollusca phylum or category. Clams are also known as shellfish. The term shellfish includes members of the mollusk phylum and the crustacean subphylum. Crustaceans include lobsters, crabs and shrimp. Crustaceans are really more related to insects than to clams.
Some shellfish or mollusks only have one shell, such as snails. Clams have two shells so they are known as bivalve mollusks. The shells are held together with a hinge. Other bivalves are oysters, cockles, mussels, scallops.
Most bivalves bury themselves in sediment, where they are relatively safe from predation. A sandy sea beach may appear to be devoid of life, but there is often a very large number of bivalves and other invertebrates living beneath the surface of the sand. Others lie on the sea floor or attach themselves to rocks or other hard surfaces. A few bore into wood, clay or stone and live inside these substances. Some bivalves, such as the scallops, can swim.
Clams live in both freshwater and marine habitats, and range in adult size from nearly microscopic to the giant clam, which can weigh 440 lb. Some clams live only one year, while others live to be over 500 years old. Clams lack heads, but most can react to changes in light and some have eyes. All clams have two shells joined near a hinge structure with a flexible ligament, and all are filter feeders. Clams also have kidneys, a heart, a mouth, a stomach, a nervous system and an anus. Many have a siphon.
There are over 12,000 clam species found throughout the world in many different habitats. Most bivalves adopt a sedentary lifestyle, often spending their whole lives in the area in which they first settled as juveniles. The majority of bivalves are infaunal, living under the seabed, buried in sand, silt, mud, gravel or coral fragments. When buried in the sediment, they are protected from the pounding of waves, desiccation and overheating during low tide, and variations in salinity caused by rainwater. They are also out of the reach of many predators. Their general strategy is to extend their siphons to the surface for feeding and respiration during high tide, but to descend to greater depths or keep their shell tightly shut when the tide goes out. They use their muscular foot to dig into the substrate.
Some bivalves, such as mussels, attach themselves to hard surfaces. They are more exposed to attack by predators than the burrowing bivalves. Others, including the true oysters, the jewel boxes, the jingle shells, the thorny oysters and the kitten's paws, cement themselves to stones, rock or larger dead shells.
Bivalves filter large amounts of water to feed and breathe but they are not permanently open. They regularly shut their valves to enter a resting state, even when they are permanently submerged.
The thick shell and rounded shape of bivalves make them awkward for potential predators to tackle. Razor shells can dig themselves into the sand with great speed to escape predation. Scallops and file clams can swim by opening and closing their valves rapidly; water is ejected on either side of the hinge area and they move with the flapping valves in front. Scallops have simple eyes around the margin of the mantle and can clap their valves shut to move sharply, hinge first, to escape from danger. Cockles can use their foot to move across the seabed or leap away from threats. The foot is first extended before being contracted suddenly when it acts like a spring, projecting the animal forwards. In many bivalves that have siphons, they can be retracted back into the safety of the shell. If the siphons inadvertently get attacked by a predator, they snap off. The animal can regenerate them later. File shells can produce a noxious secretion when stressed.
The giant clam is the largest immobile mollusc in the world, reaching up to 6 feet in length. It is not uncommon for these giant molluscs to live for more than 100 years.
Mother-of-pearl, or nacre, is a blend of minerals that are secreted by oysters and other mollusks and deposited inside their shells, coating and protecting them from parasites and foreign objects. Nacre is the same substance that is deposited around an object that becomes lodged in the mollusk to become a pearl. Most bivalves can create pearls. Pearls are formed inside the shell of certain mollusks as a defense mechanism against a potentially threatening irritant such as a parasite inside the shell, or an attack from outside that injures the mantle tissue. The mollusk creates a pearl sac to seal off the irritation. Pearls are commonly viewed by scientists as a by-product of an adaptive immune system-like function.
Clams are important biologically; they work as marine filters as they take in harmful waste nutrients like ammonia and nitrate and expel clean water to the environment. The symbiotic zoothanthellae found within its mantel tissue produces oxygen during photosynthesis.
THREATS TO CLAMS
Clams are threatened by unsustainable collection for seafood restaurants and the ornamental fish trade. Shells are sold as decorative souvenirs. Ocean acidification may also be threatening clams.
Despite all eight species of giant clams in the world being listed under Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) which prohibits unrestricted trade between countries, giant clams are constantly found in seafood stores and prized in the ornamental fish trade. Giant clams are also listed as ‘Vulnerable’ in the IUCN Red List of Endangered Animals. These listings reflect the global concern regarding the possible extinction of giant clams as a whole.
Spring rains and warmer temperatures bring out the spotted salamander. These amphibians are purple, with yellow spots, and grow up to 8 inches long.
The spotted salamander is normally secretive, living beneath rocks or under logs. They spend only two weeks or so above ground every year, feeding at night on worms, slugs, spiders and millipedes. They can secrete a noxious milky toxin from glands in their backs and tails to discourage would-be predators.
The spotted salamander offers a unique lesson in procreation. When mating, males circle a female, often so many that they form a grapefruit-size ball of animals in the water. Males drop sperm packets that the female will then choose from. When she has made her choice, she will bring the sperm into her body to fertilize her eggs. Breeding finished, the salamanders move back into the woods and hide themselves again.
Spotted salamanders are among those amphibians, programmed through evolution, to return to the water where they were born to breed. They breed in “vernal pools”, a temporary gathering of water that is too shallow to support fish that would eat the salamander’s eggs. When conditions are right, you might see hundreds of them making their way, up to a half-mile, through the woods to reach their birth pool. Vernal pools derive their name from the Latin “vernus”, meaning “belonging to spring”. Every spring, these small wetlands fill with water and blossom into life, only to dry up and disappear into the forest floor by autumn.
The multifarious organisms that inhabit a vernal pool race against time and compete with each other to flourish in a fragile environment, where rain one day too late can mean the end of their genetic survival. Each pool is a self-contained microcosm. With a single dip of the net, a student of nature can find an incredible wealth of life forms and adaptations. It is a world full of beauty and drama, close to our homes, yet one that most of us have never seen. Sadly, as development destroys our green spaces and woodlands, these pools are becoming one of nature’s most rapidly disappearing natural gems.
THREATS TO SALAMANDERS
A general decline in amphibian species has been linked with the fungal disease chytridiomycosis. A higher proportion of salamander species than of frogs or caecilians are in one of the at-risk categories established by the IUCN. Salamanders showed a significant diminution in numbers in the last few decades of the 20th century, although no direct link between the fungus and the population decline has yet been found. Deforestation, resulting in fragmentation of suitable habitats, and changes in climate are possible contributory factors.
The Chinese giant salamander, at 6 feet the largest amphibian in the world, is critically endangered, as it is collected for food and for use in traditional Chinese medicine. The hellbender is another large, long-lived species with dwindling numbers and fewer juveniles reaching maturity than previously. Habitat loss, silting of streams, pollution and disease have all been implicated in the decline.
Of the 20 species of minute salamanders in Mexico, half are believed to have become extinct and most of the others are critically endangered. Specific reasons for the decline may include climate change, chytridiomycosis, or volcanic activity, but the main threat is habitat destruction as logging, agricultural activities, and human settlement reduce their often tiny, fragmented ranges.
Hammerhead sharks, which belong to the family Sphyrnidae, are some of the most unique looking creatures in the ocean. There are ten distinct species of these sharks, which most people recognize by their distinctive head shape; a flattened, extended structure that’s called a cephalofoil. (A related and slightly different hammerhead species, the winghead shark, is classified under the family name Eusphyra instead.)
Hammerhead sharks tend to prefer warm water living, so they’re usually found in ocean habitats that are close to coastlines and continental shelves – they’ve been found in the Gulf of Mexico and off the Californian coast, as well as in Colombian, Costa Rican, Hawaiian, Australian, and southern and eastern African coastal waters. Depending on the year and weather phenomena such as El Niño conditions, some hammerheads may migrate seasonally, swimming towards warmer waters closer to the equator in the winter and northward towards the poles in the summer.
These large sharks can grow to quite a significant size, depending on their age and sex. The largest species, the great hammerhead, can range from 3 feet to over 19 feet in length, and may weigh from 6.6 to as much as 1,278 pounds. Other species of hammerheads are usually much smaller, however, and all species of hammerheads have an average lifespan of 25 to 35 years.
They’re light in color with a tall, straight dorsal fin, and their slight green skin tint and white underbelly allows them to blend well into the ocean and sneak up on prey below.
A hammerhead’s head shape, of course, is the most interesting part of their anatomy; their heads have flat projections that extend out on either side, with their eyes actually placed on either side of the hammer shape at the outer edges allowing them a 360 degree view of what’s above and below them at all times.
All sharks have special sensory pores that detect the tiny electrical fields made by other animals (called ampullae of Lorenzini), but on a hammerhead shark, these pores are spread out over a wider area giving them a larger advantage when sweeping for their next meal to eat.
Typically, hammerheads have a smaller mouth than other sharks, hunting mainly close to the bottom of the ocean. Some species (like the scalloped and smooth hammerhead) travel in schools with other hammerheads during the day, though they separate themselves to hunt alone at night.
Hammerheads are efficient and carnivorous ocean hunters that eat a range of different prey, including fish, squid, octopus, crustaceans, and sometimes other sharks. Their favorite food, however, is stingrays, which they stalk and pin down with their mallet-shaped head. Great hammerhead sharks are more likely to occasionally eat other hammerheads, including their own young on occasion.
Reproduction can also be a rather dangerous business for hammerhead females. Usually happening only once a year, a female shark is persuaded to mate with a male hammerhead by violent episodes of biting until she agrees to the coupling. After sperm is transferred to the female, eggs are fertilized inside her and embryos begin to develop, at first being nourished only by a yolk sac. After the yolk is gone, however, the sac then transforms into a structure that resembles a mammal’s placenta, allowing the young sharks to be sustained by the mother’s body until they’re developed enough to be born. At this point, the mother can give birth to a litter of 12 to 15 live shark pups (great hammerheads can birth up to 40 pups), which tend to be born in the spring or summer months, and stay together for protection and safety as they swim for warmer, shallower waters. Neither of the shark parents provides any further care to the pups after birth.
As for their threat to people, most hammerheads are harmless, and only three hammerhead species have been noted as being dangerous at all. Scalloped, great, and smooth hammerheads have been known to attack humans, but there are no listed deaths on record for a hammerhead attack against a person.
THREATS TO HAMMERHEADS
Unfortunately for these fascinating fish, we humans are their largest threat. Overfishing and the shark fin trade (where a shark’s fins are harvested as a delicacy, but the remainder of the shark is thrown back into the ocean) have put some hammerhead species at risk of extinction.
Two species, the great and scalloped hammerhead, are listed by the World Conservation Union as endangered, and the smalleye hammerhead has a ‘vulnerable’ status.
Interestingly, Hawaii may be one of the safest places for hammerhead sharks to exist at the moment. Native Hawaiian culture reveres sharks, believing some species to be reincarnated family members or the chosen ‘birth animals’ for some children, and the hammerhead shark in particular is seen as a highly respected animal and a good omen.
Armadillos are barrel-shaped animals covered with natural armor. They are the only mammals with shells. Armadillos are native to the Americas, with over 20 species of armadillo inhabiting the American continent. One species of armadillo inhabits the United States, while nine-banded armadillos are the only armadillo species outside of the South American tropics.
Most armadillos prefer wetlands with thick shade and sandy soil that is easy to dig. Some armadillos live in grasslands, woodlands or thorn scrubs. Armadillos burrow underground, in grass, and into hollow logs. Armadillos have a low metabolic rate, meaning they have naturally low body temperatures.
Armadillos vary greatly in size. The smallest armadillo is the tiny, pink fairy armadillo. The giant armadillo is the largest species. Armadillos can be gray, pink, red, yellow or black.
Armadillos have strong legs and long claws for hunting underground insects and digging. They have small eyes and poor vision so rely heavily on their highly developed sense of smell. They also use the wiry hairs along their sides and bellies to feel their way around. Armadillos have pointy snouts and long, sticky tongues, much like anteaters – their close cousins.
The armadillo's protective shell is constructed of plates of bone covered with small, overlapping scales called scutes. One species can curl into a ball when threatened by predators. Their undersides, soft skin and fur are protected when they curl up. Other species of armadillo run, dig, or press their bodies down in the ground to keep from getting flipped over by a predator. Armadillos can outrun most predators. They run amazingly fast. Some armadillos can also jump quite high into the air when startled. The screaming hairy armadillo emits an extremely loud, alarm-like vocalization when frightened.
Armadillos are insectivores, feeding mostly on insects. They use their long, sticky tongues to extract ants and termites from their tunnels. Armadillos may also eat worms, spiders, snakes and frogs. An armadillo's diet varies based on their habitat.
Armadillos are good swimmers. They can fill their stomachs and intestines with air to float. Armadillos can hold their breath for 6 minutes, and even walk along the bottoms of ponds, lakes and rivers.
Most armadillos are solitary animals, coming together only to mate or to keep warm during colder temperatures. They cuddle up with leaves and grass. Armadillos spend much of their time sleeping, up to 16 hours a day. Armadillos usually forage for food in the mornings and evenings. In hotter months, armadillos may be nocturnal, active at night. One species of armadillo hibernates in the winter.
Breeding season for armadillos varies by species. An armadillo can have up to 56 babies during their lifetime – from one to 12 babies at a time. Mother armadillos give birth following an up to five month gestation period. Baby armadillos have soft shells when first born, which harden quickly. They live with their mother for a few months, feeding only on her milk. Father armadillos do not assist with raising the young. Their mother teaches her baby armadillos how to forage. Baby armadillos are independent in six months to one year.
Armadillos are preyed upon by several predators, including bears, wolves, wildcats, birds of prey, dogs and cougars.
Armadillos can live up to 30 years in the wild.
THREATS TO ARMADILLOS
Armadillos are threatened by habitat loss, hunting for their meat and shells, pollution, pesticides, vehicle collisions and animal agriculture. They are often viewed as pests and exterminated. Most armadillo species are quickly decreasing in population. Armadillos are also inhumanely captured to sell in the illegal exotic pet trade. Most captive armadillos die quickly after being caged and transported.
Spiders are invertebrates but are not considered insects because they only have two main body parts instead of three, eight legs instead of six and no antennae. Most spiders also have eight simple eyes, while insects have large, compound eyes. Some have no eyes and others have as many as 12. Spiders, along with ticks, mites, harvestmen and scorpions, are called arachnida. They are also classified into a special group called araneae because they have very slender waists compared to other arachnida.
Spiders are found worldwide on every continent except for Antarctica, and have become established in nearly every habitat. Over 43,000 spider species have been recorded.
Most spiders are carnivorous, usually feeding on insects. Some are big enough to prey on larger animals such as mice or small birds. Without spiders, insect numbers would skyrocket and bugs would devour our crops. Most spiders eat about 2,000 insects a year.
Some spiders live in silk-lined burrows and leap out to capture prey. Some lie in ambush. Some go hunting in search of prey and others spin webs to entrap them. Some spiders capture prey with silk-made nets, and others use spider silk as "fishing lines". Spider silk is also used to protect their babies, to create shelters and to assist them as they move and reproduce. Some spiders even build "submarines" that hold air so they can stay under water. Most live on land, but a few live in and on water and can run across water.
Spider webs are made of continuous strands of spider silk produced from glands under their bellies. Most take about 60 minutes to construct. The webs have three parts: the frame, built first and attached to plants or other objects; the radii, which radiate out from the center like spokes of a bicycle and transmit vibrations from prey; and the catching spiral, the sticky threads that stretch without breaking making it difficult for insects to escape.
Small and young spiders can travel for miles on air breezes, a travel method called ballooning. To lure other spiders from their webs, the jumping spider plucks rhythms at the corner of a web to mimic a trapped insect.
Male spiders identify themselves by a variety of complex courtship rituals to avoid being eaten by the females. In web-weaving species precise patterns of vibrations in the web are a major part of the rituals. Patterns of touches on the female's body are important in spiders that hunt actively, and may "hypnotize" the female. Gestures and dances by the male are important for jumping spiders, which have excellent eyesight. Males of most species survive a few matings, limited mainly by their short life spans.
Females weave silk egg-cases, each of which may contain hundreds of eggs. Baby spiders pass all their larval stages inside the egg and hatch as spiderlings, very small and sexually immature but similar in shape to adults.
Females of many species care for their young, for example by carrying them around or by sharing food with them. Some spider mothers respond to the "begging" behavior of their young by giving them their prey, provided it is no longer struggling, or even regurgitate food. Like other arthropods, spiders have to molt to grow as their skin cannot stretch.
Some spider species are social, building communal webs that may house anywhere from a few to 50,000 individuals. Social behavior ranges from precarious toleration to co-operative hunting and food-sharing. Social predatory spiders need to defend their prey against thieves, and larger colonies are more successful in this. The herbivorous spider Bagheera kiplingi lives in small colonies which help to protect eggs and spiderlings. Even widow spiders, which are notoriously cannibalistic, have been known to form small colonies, sharing webs and feeding together.
Although spiders are generally regarded as predatory, some feed on plants and nectar. Various species are known to feed on dead arthropods (scavenging), web silk, and their own shed exoskeletons. Pollen caught in webs may also be eaten.
The best-known method of prey capture is by means of sticky webs. Varying placement of webs allows different species of spider to trap different insects in the same area. For example, flat horizontal webs trap insects that fly up from vegetation underneath while flat vertical webs trap insects in horizontal flight. Web-building spiders have poor vision, but are extremely sensitive to vibrations.
Some water spiders build underwater "diving bell" webs which they fill with air and use for digesting prey, molting, mating and raising offspring. They live almost entirely within the bells, darting out to catch prey animals that touch the bell or the threads that anchor it. A few spiders use the surfaces of lakes and ponds as "webs", detecting trapped insects by the vibrations that these cause while struggling.
Net-casting spiders weave only small webs but then manipulate them to trap prey. Some stretch their webs and then release them when prey strike them, but do not actively move their webs. Others weave smaller webs, hold them outstretched between their first two pairs of legs, and lunge and push the webs to trap prey. Some spiders emit chemicals that resemble the pheromones of other animals to attract prey.
Trapdoor spiders and many tarantulas are ambush predators that lurk in burrows, often closed by trapdoors and often surrounded by networks of silk threads that alert these spiders to the presence of prey. Other ambush predators do without such aids, including many crab spiders. A few species that prey on bees, who see ultraviolet, can adjust their ultraviolet reflectance to match the flowers in which they are lurking. Wolf spiders, jumping spiders, fishing spiders and some crab spiders capture prey by chasing it, and rely mainly on vision to locate prey. Some spider species mimic different ant species. They look like ants and modify their behavior to resemble that of the target species of ant.
Although most spiders live for, at most, two years, tarantulas and other mygalomorph spiders can live up to 25 years.
THREATS TO SPIDERS
Like most animals, the primary threat to spiders is the destruction of their habitat. Human development has taken an alarming toll on the environment. Impact from land use practices such as agricultural conversion, deforestation, and urban sprawl continue to degrade and fragment remaining pockets of habitat and accelerate biodiversity loss. Pesticides and other forms of pollution are also of serious concern, as well as genetically modified organisms (GMOs).
Spiders are also victims the pet trade, sold for a short life in captivity for human amusement. Captivity is cruel for wild animals. The physical and physiological needs of animals can never be met in captivity.
Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" (abdomen), usually entirely hidden under the thorax. They live in all the world's oceans, in fresh water, and on land. They are generally covered with a thick exoskeleton and have a single pair of claws. Many other animals with similar names – such as hermit crabs, king crabs, porcelain crabs, horseshoe crabs and crab lice – are not true crabs.
Crabs vary in size from the pea crab, a few millimeters wide, to the Japanese spider crab, with a leg span of up to 13 feet. Males often have larger claws. In most male crabs, the abdomen is narrow and triangular in form, while females have a broader, rounded abdomen. This is due to the fact that female crabs brood fertilized eggs on their legs.
Crabs attract a mate through chemical (pheromones), visual, acoustic or vibratory means. Pheromones are used by most fully aquatic crabs, while terrestrial and semi-terrestrial crabs often use visual signals, such as fiddler crab males waving their large claw to attract females. Many crabs have internal fertilization and mate belly-to-belly. For aquatic species, mating usually takes place just after the female has moulted and is still soft. Females can store the sperm for a long time before using it to fertilize their eggs. When fertilization has taken place, the eggs are released onto the female's abdomen, below the tail flap, secured with a sticky material. In this location they are protected during embryonic development. Females carrying eggs are called "berried" since the eggs resemble round berries.
When development is complete, the female releases the newly hatched larvae into the water, where they are part of the plankton. The release is often timed with the tides. The free-swimming tiny zoea larvae can float and take advantage of water currents.
Each species has a particular number of stages, separated by moults, before they change into a megalopa stage, which resembles an adult crab, except for having the abdomen (tail) sticking out behind. After one more moult, the crab is a juvenile, living on the bottom rather than floating in the water. This last moult must take place in a habitat that is suitable for the juvenile to survive.
Most species of terrestrial crabs must migrate down to the ocean to release their larvae; in some cases this entails very extensive migrations. After living for a short time as larvae in the ocean, the juveniles must do this migration in reverse.
Once crabs have become juveniles they still have to keep moulting many more times to become adults. They are covered with a hard shell, which would otherwise prevent growth. The moult cycle is coordinated by hormones. When preparing for moult, the old shell is softened and partly eroded away, while the beginnings of a new shell form under it. At the time of moulting, the crab takes in a lot of water to expand and crack open the old shell. The crab must then extract itself from the old shell. This is a difficult process that takes many hours, and if a crab gets stuck it will die. After freeing itself from the old shell the crab is extremely soft and hides until its new shell has hardened. While the new shell is still soft, the crab can expand it to make room for future growth.
Crabs typically walk sideways. However, some crabs walk forwards or backwards. Some crabs are also capable of swimming.
Crabs are active, complex animals. They can communicate by drumming or waving their pincers. Crabs tend to be aggressive towards one another and males often fight to gain access to females. On rocky seashores, where nearly all caves and crevices are occupied, crabs may also fight over hiding holes. Fiddler crabs dig burrows in sand or mud, which they use for resting, hiding, mating and to defend against intruders.
Crabs are omnivores, feeding primarily on algae, and taking any other food, including molluscs, worms, other crustaceans, fungi, bacteria and detritus, depending on their availability and the crab species. For many crabs, a mixed diet of plant and animal matter results in the fastest growth and greatest fitness. However, some species are more specialized in their diets. Some eat plankton, some eat primarily shellfish like clams, and some even catch fish.
Crabs are known to work together to provide food and protection for their family, and during mating season to find a comfortable spot for the female to release her eggs. They will help other crabs fight off intruders. Neighboring crabs never fight with each other.
Many mother crabs provide loving care for their babies. Mothers continue to feed and tend to their babies for several months after they are born. They work hard to keep their homes clean and comfortable for their young.
Crabs are intelligent animals, capable of learning from their mistakes and retaining that information so they don’t make the same mistakes again. They adapt to changing cues in their environment.
THREATS TO CRABS
Crabs are threatened with declining habitats, pollution, overfishing and the declining abundance of coral reefs. Crabs make up 20% of all marine crustaceans caught, farmed, and consumed worldwide, amounting to 1½ million tons annually. In some species, crab meat is harvested by manually twisting and pulling off one or both claws and returning the live crab to the water in the belief the crab will survive and regenerate the claws thereby making it a sustainable industry. Crabs are often inhumanely boiled alive. Crustaceans are able to feel and remember pain. They fight so hard against a clearly painful death that their claws often break off in their struggle to escape. Some crabs used for food are electrocuted, some are chopped up, and others are microwaved—all while they are still conscious.
Members of one of the most diverse groups of lizards, skinks are reptiles with cylindrical, streamlined bodies, functioning eyelids and tight, smooth, scaly skin. They belong to the family Scincidae, and their name comes from the Greek word skinkos, which was a name that was used to refer to lizards in a specific region of the country. Over 1500 distinct species of skinks have been described, living in a wide range of habitats worldwide, from dry deserts, to mountains, grasslands and forests.
Although skinks are close in appearance to ‘true lizards’ (such as wall lizards, for example), they don’t have a distinct neck, and their legs tend to be smaller. Interestingly, some species of skink actually have reduced limbs or even no limbs at all, making their movement appear far more like a snake than a lizard - which is what many people may mistake them for. A few certain skink species, like the blue-tongued skink, also tend to be more broad-headed and wider-bodied than their relatives.
The particular living environment of a skink can often be determined merely by its toe length – generally, the longer a skink’s digits (toes), the more likely it is to spend most of its time climbing in trees.
These unusual reptiles tend to be small to medium sized, on average, depending on the species. They can range from specimens as tiny as the little brown skink at 3 inches, to as large as the Solomon Islands skink at 14 inches, though their tails usually make up more than half of that length.
Many skink species are escape artists. They can shed their tails when necessary if predators grab them, and can re-grow the lost part. The shed tail will actually wiggle for a short period of time after being lost, which serves to distract any potential predators while the skink makes its escape. Skinks may also return to the lost tail and ingest it in order to regain lost nutrient value.
Active, quick, and agile little lizards, skinks can dart rapidly from place to place when they’re not found basking on warm rocks or logs. Offspring-bearing females or mating pairs tend to be slower, however. Some species of these lizards are tree-climbing, but for the most part, most tend to live in ground habitats (so they’re terrestrial, in other words), or prefer to burrow through sand. They’re most active in the daytime.
Skinks like to stay safe and out of the reach of predators or bad weather, and make their nests in secure, hidden areas. For some, this can mean a nest in the dirt or under heavy brush cover. For other skinks (especially those in and around urban areas) rotting boards, garages or spaces under structures like sheds can be suitable nesting areas. Some nests can contain anywhere from 10 to 30 skinks at a time, and it’s not unusual for skinks to actually ‘guard’ their territory. A small number of skink species are also water-dwelling, but these tend to be the exception.
Skinks are fairly predictable eaters. Being carnivorous lizards, their menu choices tend to run to insects like flies, beetles and caterpillars, but some may even eat snails or small rodents. They sniff out prey using their tongue, and then chase it down, corner it, and usually swallow it whole.
The method of producing young can be different from species to species of skink. Male skinks will sometimes fight each other for the privilege of mating with a certain female by biting each other on the head, neck or tail. Male-female pairs in some species will form monogamous relationships from year to year. Just under half of all skink species birth live young, nourishing their offspring though a placenta-like organ. Other species hatch their eggs internally instead, and then give birth to young after that. Still others lay eggs which hatch outside their body.
Females tend to be protective of their eggs, coiling around them and guarding against predators, and will often stay to protect their new offspring for the first few days until they leave the nest. Skinks can have significant gestation times, typically several months and as long as one year in some species. They have been noted to have as few as 1 or as many as 67 young born at one time.
THREATS TO SKINKS
Although many skinks are highly adaptable when it comes to their nesting situation, they also have a large number of natural predators. Raccoons, snakes, crows, herons, hawks and other lizards may see skinks as a tasty meal.
Because the skink’s long gestation period means that they can’t replenish their population numbers as quickly as other animals, overhunting by larger invasive predators like the mongoose has caused skink species in some areas to approach extinction. The Anguilla Bank skink in the Caribbean is one example.
The Coccinellidae are a family of small beetles, commonly known as ladybugs in North America and ladybirds in Britain, Ireland, the Commonwealth and some parts of the southern United States. Entomologists in the United States prefer the names ladybird beetles or lady beetles, as these insects are not true bugs.
Coccinellids are found worldwide, with over 5,000 known species. They are often yellow, orange, or scarlet with small black spots on their wing covers, with black legs, heads and antennae. Color patterns vary greatly, however. Depending on the species, they can have spots, stripes, or no markings at all. Many species are mostly, or entirely, black, dark gray, gray, or brown. Seven-spotted coccinellids are red or orange with three spots on each side and one in the middle; they have a black head with white patches on each side. Most coccinellids have oval, dome-shaped bodies with six short legs.
The four most common types of ladybugs are:
The round-shaped ladybugs, Seven-spotted ladybug, originally from Europe. They are round and have a dome-shape, and are bright red with seven spots of black on the back of their bright red wings.
The oval-shaped ladybug, Convergent ladybug, which is orange with different spot patterns of black. They are common in the pacific coastal states.
The Multicolored Asian ladybeetle, a larger ladybug with five black spots and curved lines in the shape of the letter M. These ladybugs are originally from Asia and are now plentiful in the United States.
The C-Mac ladybug, an oblong pink and black spotted ladybug.
Ladybugs are generally considered useful insects, because many species feed on aphids or scale insects which are pests in gardens, agricultural fields, orchards and similar places. Within the colonies of such plant-eating pests, they will lay hundreds of eggs. When these hatch the larvae will commence feeding immediately. However, some species do have unwelcome effects; among these the most prominent are the subfamily Epilachninae, which are plant eaters. Usually, Epilachninae are only mild agricultural pests, eating the leaves of grain, potatoes, beans, and various other crops. But their numbers can increase explosively in years when their natural enemies, such as parasitoid wasps that attack their eggs, are few. In such situations, they can do major crop damage. They occur in practically all the major crop-producing regions of temperate and tropical countries.
Coccinellids are best known as predators of aphids and scale insects, but the range of prey species that various ladybugs attack is much wider. Some specialize in mites, some attack caterpillars and other beetle larvae. Others feed on various insects or their eggs. Larvae and eggs of ladybirds, either their own or of other species, can also be important food resources when alternative prey are scarce. Certain species of coccinellids are thought to lay extra infertile eggs with the fertile eggs, apparently to provide a backup food source for the larvae when they hatch. The ratio of infertile to fertile eggs increases with scarcity of food at the time of egg laying. Ladybugs are also now known to be far more omnivorous than previously thought. Their diets often include honeydew, pollen, plant sap, nectar, and various fungi. Some species are strictly herbivores.
The main predators of ladybugs are usually birds, but they are also the prey of frogs, wasps, spiders, and dragonflies. The bright colors of many ladybugs discourage some potential predators from making a meal of them. Their coloring is a reminder to any animals that have tried to eat their kind before that they taste awful. The blood of a ladybug is yellow and has a very strong smell that also acts as a repellent to predators. Ladybugs also play dead until predators pass.
Ladybugs in temperate regions enter diapause (a period of suspended development) during the winter, so they often are among the first insects to appear in the spring. Some species gather into groups and move to higher elevations, such as a mountain, to enter diapause. Most coccinellids overwinter as adults, aggregating on the south sides of large objects such as trees or houses during the winter months, dispersing in response to increasing day length in the spring.
Ladybugs go through a complete metamorphosis with egg, larval, pupal, and adult stages. Ladybug eggs look like small clusters of orange footballs. Female ladybugs can lay more than 2,000 eggs in one year. The eggs hatch in only a few days. Eggs are usually laid on leaves near an area where the larvae have easy access to food sources.
Baby ladybugs, larvae, look nothing like adults. They are long in shape and are generally one color, resembling small alligators. They are fast moving and they have big appetites. The larvae will eat aphids and other bugs for about 2 to 3 weeks. After they have grown to full size, they attach themselves to a plant leaf or a stem by their tail and begin a metamorphosis. Their skin splits down its back and exposes the pupa, which is about the same size and color as adults but with a protective layer until they develop wings. They pupate and turn into an adult ladybug within 7 to 10 days.
Ladybugs usually do most of their flying in the warmest part of the afternoon. They beat their wings 85 times per second. Their wings are made from chitlin, the same material human fingernails are made from.
As ladybugs grow older, their spots fade. Most ladybugs live for about a year, but some species can live up to three years. In a year they eat over 5,000 bugs, playing a vital role in the management of pests.
THREATS TO LADYBUGS
Due to habitat loss and changes in climate, ladybugs are threatened with extinction. Ladybugs are particularly sensitive to temperature changes, and will die from dehydration if they become overheated. Like most animals, the primary threat to ladybugs is the destruction of their habitat. Human development has taken an alarming toll on the environment. Impact from land use practices such as agricultural conversion, deforestation, and urban sprawl continue to degrade and fragment remaining pockets of habitat and accelerate biodiversity loss. Pesticides and other forms of pollution are also of serious concern, as well as genetically modified organisms (GMOs).
Sharks are members of a group of almost exclusively marine and predaceous fishes. There are about 250 species of sharks, ranging from the 2 feet pygmy shark to 50 feet giants. They are found in all seas, but are most abundant in warm waters. Some may enter large rivers, and one ferocious freshwater species lives in Lake Nicaragua. Most are predatory, but the largest species, the whale shark and the basking shark, are harmless plankton eaters. Dogfish is the name for members of several families of small sharks; these should not be confused with the bony dogfishes of the mud minnow and bowfin families.
Sharks are heavy fishes, possessing neither lungs nor swim bladders. Their skeletons are made of cartilage rather than bone, and this, along with large deposits of fat, partially solves their weight problem. Nevertheless, most sharks must keep moving in order to breathe and to stay afloat. They are good swimmers; the wide spread of the pectoral fins and the upward curve of the tail fin provide lift, and the sweeping movements of the tail provide drive. Their tough hides are studded with minute, toothlike structures called denticles. Sharks have pointed snouts. Their crescent-shaped mouths are set on the underside of the body and contain several rows of sharp, triangular teeth. They have respiratory organs called gills, usually five on each side, with individual gill slits opening on the body surface. These slits form a conspicuous row and lack the covering found over the gills of bony fishes.
Like most fishes, sharks breathe by taking water in through the mouth and passing it out over the gills. Usually there are two additional respiratory openings on the head, called spiracles. A shark's intestine has a unique spiral valve, which increases the area of absorption. Fertilization is internal in sharks; the male has paired organs called claspers for introducing sperm into the cloaca of the female. Members of most species bear live young, but a few of the smaller sharks lay eggs containing much yolk and enclosed in horny shells. Compared to bony fishes, sharks tend to mature later and reproduce slowly.
Only a small number of the predatory species are definitely known to occasionally engage in unprovoked attacks on humans. The largest and most feared of these is the great white shark, which may reach 20 feet in length and is probably responsible for more such attacks than any other species. Other sharks reputed to be slightly dangerous are the tiger and blue sharks and the mako. Sharks are extremely sensitive to motion and to the scent of blood. Swimmers in areas where dangerous varieties occur should leave the water quietly if they are cut. In some places bathing areas are guarded by nets. A number of substances have been used as shark repellents, but their effectiveness is variable. Sharks usually circle their prey before attacking. Since they seldom swim near the surface, an exposed dorsal fin is more likely to be that of a swordfish or ray than that of a shark.
Sharks can range from being just inches in length (like the tiny cookie cutter shark) to being larger than a school bus (like the giant plankton-eating whale shark). Though sharks perform the same role in the ocean ecosystem that is performed by well-known predators such as lions, tigers, and cheetahs on land, the fact that they live in such an alien world makes it hard for us to know about their lives. What we do know is pretty fascinating.
Sharks shed their teeth. A single shark may lose thousands of teeth over its life and this accounts for the many shark teeth found by beach combers throughout the world. Their teeth are connected to a membrane in their mouth that is constantly being pushed forward as new teeth form. New teeth are generally slightly larger than the ones before. This allows the size of the shark's teeth to keep pace with the growth of the rest of the body.
Sharks are picky eaters. Some sharks eat only plankton, others eat small fish or squid, and still others eat large fish and marine mammals. The type of teeth a shark has will show you what it eats. Great white sharks have teeth with serrated edges for slicing off pieces from larger prey, the teeth of mako sharks are thin and pointed for grabbing onto slippery fish. Nurse sharks and other bottom dwellers tend to have thicker teeth for crushing shellfish. No matter the tooth shape, sharks never chew their food.
You're more likely to die as a result of being electrocuted by holiday lighting than being attacked by a shark. More deadly than shark attacks each year are crocodile attacks, hippo attacks, and even attacks by pigs.
Many sharks are warm blooded. Unlike the rest of the fishy world, many large sharks can maintain their body temperature higher than the ocean temperature around them. We don't know whether sharks sleep. Sometimes they seem to rest, but their eyes don't close and if they sleep, they certainly don't sleep the way that mammals can.
THREATS TO SHARKS
Don't be afraid OF sharks; be afraid FOR them. There are more misunderstandings and untruths about sharks than almost any other group of animals on the planet. While many people fear sharks, it is the sharks who should be fearing us.
According to the shark attack file, maintained by the Florida Museum of Natural History, on average 5 people die worldwide from shark attacks. Up to 70 million sharks are killed by humans each year, mostly for their fins. This is a devastating death toll for a long-living species that is as slow to reproduce as sharks.
Sharks have roamed the oceans far longer than most land animals have been here. They were here before many of the dinosaurs and have outlasted them. But an international assessment of sharks undertaken by the World Conservation Union reveals that their future is in doubt. Of 546 shark species assessed, 111 species were at significant risk of global extinction. Twenty species are listed as critically endangered and 25 as endangered. Some shark species have lost 80% of their populations just in the past 40 years including hammerhead sharks, thresher sharks, and porbeagle sharks. While hammerhead shark is a name familiar to most, most people have never heard of porbeagle sharks; some of the lesser known sharks are in even greater danger.
There is a lot we don't know about sharks, but we DO know that if we don't act soon to stop overfishing, some of the most ancient and magnificent animals on the planet may soon disappear.
Lynx is a member of the cat family. There are four species of lynx within the Lynx genus: Spanish, Canadian, Eurasian lynx and the bobcat.
These medium-sized wild cats have short tails, tufts of black hair on the tips of their ears, large whiskers and a ruff under their necks with black bars resembling a bow tie. Their padded paws are large, allowing them to easily walk on snow.
The bobcat and the Canada lynx are the smallest species; the Eurasian lynx is the largest species; while each species may vary considerably.
Lynx coloring varies according their climate; from gold to beige-white to medium brown. Some have dark brown spots, especially on their legs. All lynx have white chests and bellies. The white fur extends to the insides of their legs. Lynx in the Southwestern United States are dark in color. In colder climates they are lighter in color.
The length of their fur and paw sizes also vary due to their climate. They are short-haired with smaller, less padded paws in the Southwestern United States. In colder northern climates, lynx have thicker, lighter colored fur and larger paws.
The Eurasian lynx lives in central and northern Europe across Asia up to Northern Pakistan and India. In Iran, they live in the Mount Damavand area. In North America, the Canada lynx and bobcat live in the temperate zone. Bobcats are common in the continental United States, southern Canada and northern Mexico. Canada lynx live in boreal forests of Alaska and Canada.
Lynx are usually solitary animals, though they sometimes travel and hunt together. Mating occurs once a year in late winter. A female gives birth to one to four kittens following a gestation period of around 70 days. Young lynx will live with their mother for another winter, or about nine months.
As young adults they live on their own, creating dens under ledges or in crevices. They prefer to occupy high altitude forests with dense grass, shrubs or reeds. They can climb trees and are proficient swimmers.
Their large paws help them to balance and hunt and to travel and hunt in snowy, high altitude habitats. Their acute hearing allows them to hear oncoming prey and predators over long distances. Sharp vision is another important sense used for hunting. Strong jaws and sharp teeth help the lynx to bite down on prey.
Lynx hunt from an ambush, using the element of surprise. These agile climbers spend most of their time in tree branches, waiting for prey to pass beneath them. Lynx eat a wide range of animals including snowshoe hares, fish, foxes, white-tailed deer, small red deer, chamois, squirrels, mice, birds, goats, sheep, voles, grouse, reindeer, roe deer and ptarmigans.
Lynx do not usually take their kill back to their den, except when a mother is providing food for her lynx kittens. They have very large ranges; the largest range of all felids. Male territories are larger and often overlap several female territories.
Lynx are very vocal cats. They meow, purr, hiss, chatter and yowl.
Lynx are nocturnal (active during the night). They are very cautious around people and predators. The main predators of lynx are cougars, coyotes, wolves, and humans.
Lynx can live over 14 years in the wild.
THREATS TO LYNX
In many countries, the hunting of lynx is illegal. Bobcat hunting and trade is common the United States, though they are classified as a state endangered species in Ohio, New Jersey, Indiana, and Iowa - and as a State threatened species in Illinois. Regulated hunting is permitted in Mexico and in Canada.
Lynx populations have been greatly reduced due to hunting and poaching by the fur industry.
The Iberian lynx is almost extinct. They are currently being captive bred to be reintroduced to the wild. Reintroduction projects have also taken place in Europe, and resettlement attempts have been attempted in the United States.
The Spanish lynx is one of the most endangered cats in the world.
The Canadian lynx is becoming very rare in the northern United States due to hunting, habitat destruction and competition with bobcats.
Barracudas are a large species of fish that live in the warmer, coastal regions of the planet's oceans. They are known for their aggressive and dominant predator behavior. There are over 20 species of barracuda in the world.
While barracudas are widely spread across the seas, they are more commonly found in tropical areas where there is an abundance of food sources. Although barracudas also live in the deep ocean, they prefer the coastal areas along continental shelves and near coral reefs. Barracudas are nocturnal animals, active during the night.
All species of barracuda have an elongated shape and a pointed head with powerful jaws housing sharp, fang-like teeth. Different species of barracudas vary in sizes and colors. Barracudas can grow to be very large. The upper part of a barracuda body is covered with scales that can be black, gray, brown or blue. A barracuda's belly is always white. Irregular dark spots are located on both sides of the barracuda's body.
Barracudas are carnivores. The barracuda feeds mainly on smaller species of fish, crustaceans, invertebrates and squid. They are opportunistic predators, feeding on other animals in the surrounding area. They use a surprise tactic to capture their prey, ambushing with tremendous power. They can swim very quickly in short bursts to overtake their prey.
Barracudas prefer a solitary life, but sometimes gather in groups called schools. Schools provide safety and cooperative hunting opportunities.
Barracudas have few natural predators. Sharks and killer whales prey on barracudas.
Mother barracudas spawn during the spring. The female barracuda releases her eggs into the ocean which are then fertilized externally by the male barracuda. Baby barracudas have little interaction with their parents.
Barracudas can live over 15 years in the wild.
THREATS TO BARRACUDAS
The biggest threats to barracudas are recreational fishing and the barracuda meat trade.
All ocean animals are threatened by pollution, the fishing industry and changes in climate. Global fish populations are collapsing, affecting all marine life. Plastics and toxic waste are destroying aquatic ecosystems. Almost half of all ocean pollution is from irresponsible human activities that take place on land, including animal agriculture, sewage, chemical spills, industrial runoff and garbage dumping.
Marine habitats are being destroyed by coastal pollution. The clearing of mangrove forests and scraping of underwater mountain ranges through deep-sea trawling are also having detrimental affects on marine ecosystems.