The Pygmy Marmoset (Callithrix (Cebuella) pygmaea) is a monkey native to the rainforest canopies of western Brazil, southeastern Colombia, eastern Ecuador, and eastern Peru. It is one of the smallest primates (The smallest primate is the pygmy mouse lemur), with its body length ranging from 14-16 cm (excluding the 15-20 cm tail) and the smallest monkey. Males weigh around 140 g (5 ounces), and females only 120 g (4.2 ounces). They have brownish-gold fur with black ticking on their shoulders, backs, and heads, while their ventral fur is light yellow to white.

Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Family: Cebidae
Genus: Callithrix
Subgenus: Cebuella
Species: C. pygmaea
Binomial name: Callithrix (Cebuella) pygmaea
Sub Species
Callithrix (Cebuella) pygmaea pygmaea
Callithrix (Cebuella) pygmaea niveiventris

Infants are born with different pelage than is seen in adults; they are a lemon-yellow color with black ticking over their bodies while the head is a dark grey with yellow fur on and around their ears. By the end of the first month, they lose this coat and resemble adults.

Adult pygmy marmosets have tails that are longer than their bodies and marked with conspicuous black rings. The fur on their faces sweeps back over their forehead and ears and they have two white marks on either side of their mouth and a white, vertical line on their noses. These facial markings probably serve to enhance perception of facial expression and head movements in visual communication in the diffuse light of dense forests.

Though they exhibit squirrel-like patterns of locomotion, including quadrupedally running up and down tree trunks, vertically clinging to tree trunks as they feed on sap, and branch and vine-running on both the top and underside surfaces of horizontal substrates, they are not more closely related to squirrels than other primates. Their small body size allows them to use very slender supports but does not inhibit their locomotion; pygmy marmosets can leap up to five meters. They are also able to turn their heads 180 degrees, an adaptation which allows them to scan the environment for predators while vertically clinging to a tree. Pygmy marmosets are able to support their weight on the tips of their long, sharp, claw-like nails (called tegulae) which are different from the flat nails (called ungulae) seen in other primates, including humans, and are probably an adaptation to a life spent clinging to trees. An additional characteristic that aids in their exudate-eating behavior is the shape of their lower incisors. They are narrow and elongated such that the five teeth in the front and center of the lower jaw are all the same length. This helps them gnaw into trees efficiently and stimulate sap flow. They also have an enlarged cecum, a part of the digestive tract which allows extended time for the breakdown of plant gums. Another unusual characteristic seen in pygmy marmosets and other callitrichines is the pattern of giving birth to non-identical twins more frequently than singletons.

Range

Found in Peru, Ecuador, Colombia, Bolivia, and Brazil, pygmy marmosets range over a large area and the subspecies are isolated by geographic barriers which include several large rivers. The northern subspecies, C. p. pygmaea, is found in the state of Amazonas, Brazil, southern Colombia, northern Bolivia, northeastern Ecuador, and eastern Peru. Its range is bound by the Rio Solimões and Rio Caquetá. C. p. niveiventris is found in eastern Peru and Amazonas, Brazil south of the Rio Solimões and north of the Rio Purus. It extends as far east as the Rio Madeira and is bound in the west by the Andes.

Habitat

Pygmy marmosets occupy mature evergreen forests in and at the edges of periodically inundated river floodplains. They are habitat specialists that prefer areas with no more than two or three meters of standing water for more than three months out of the year and are found in highest densities in river-edge forests. If they are found in highland areas, it is usually along small, seasonal forest streams that are subjected to frequent, minor flooding. They utilize vertical strata of the forest from ground level up to 20 m (65.6 ft) and rarely venture into the highest level of the canopy. The understory is composed of reeds, tall grasses, and a few herbaceous plants, vines, shrubs, and saplings. There are also dense thickets formed by bamboo reeds, shrubs, and vines. The tallest trees in this area often have crown heights between 30 and 40 m (98.4 and 131 ft) which support hanging vines and epiphytes.

Data on rainfall and temperature have been reported for a study site in Peru in the Rio Maniti basin where the rainy season lasts from October to May and the dry season lasts from June to September. The highest amount of rain falls in March, with levels reaching more than 340 mm (1.12 ft). During the driest part of the year, only about 150 mm (5.9 in) of rain falls per month. Temperatures remain fairly constant throughout the year, hovering around 27° C (80° F) and 80% humidity. In Ecuador at the Cuyabeno Faunal Production Reserve, average monthly rainfall from March to August exceeds 250 mm (9.84 in) with considerably drier periods during September through February. Average temperatures fluctuate between 22 and 29° C (71 to 84° F) with the rainy season seeing warmer temperatures.

Rivers begin to rise in the beginning of the dry season such that between February and June, the floodplain becomes inundated. During this time, there is an abundance of fruits, but as the floodplain dries out during the dry season, fruits also become noticeably scarce.

Ecology

Characteristics such as elongated, sharp incisors and claw-like nails are adaptations to the very specific diet of the pygmy marmoset -- gums and other exudates. They are exudativore -insectivores and spend the majority of their time gouging holes into trees or vines with their sharp lower teeth and then eating the gum, sap, resin, or latex that is exuded. Holes are generally ten to 20 mm (.787 in) wide, four to 18 mm (.157 to .709 in) deep, and nearly perfectly circular. The "oldest" holes on a tree are closer to the ground and they get "newer" farther up the tree, indicating a pattern of usage. Insects make up the other important part of the diet, and grasshoppers are especially coveted. Pygmy marmosets forage in the crown foliage of trees at about five to 15 m off the ground, looking in vine-tangles and shrubby vegetation for spiders, orthopterans, butterflies, moths, beetles, and ants.

While 60 to 80% of their total feeding time is spent on exudates, they spend between 12 and 16% on insects, and supplement their diet with fruits, buds, flowers, nectars, and very occasionally small lizards.

Pygmy marmosets use sleeping sites, or roosts, each night and their day starts shortly after sunrise when all members of the group leave the sleeping site. Sleeping sites are generally made of dense tangles of vines or, on rare occasion, tree holes. Each group has two or three sleeping sites but only use one on a regular basis. In heavy rain or dark, overcast mornings, pygmy marmosets take up to an hour longer to leave the sleeping site. Once it has left the roost, the group travels directly to their primary exudate tree where the marmosets feed for 30 to 90 minutes on gum that has been exuded during the night. After this feeding bout, there is a shift in activity to more social activities such as huddling, grooming, and playing. After this brief period of rest from foraging, the group begins to focus on insect foraging and exudate foraging until midday when rest and social behavior become the predominant activities. Intense feeding activities begin again in late afternoon until the group travels back to the roost for the night. The two peaks of exudate feeding occur between 6:00 and 9:00 a.m. and again between 3:00 and 6:00 p.m. Activities are not always coordinated between all group members; some may be foraging for insects while others are feeding on exudates nearby.

A pygmy marmoset group, ranging in size from two to nine individuals, utilizes a primary exudate tree in its home range until the exudate yield declines at which point they gradually move to a new area, if one is available, in the vicinity of the old home range. Groups of pygmy marmosets exchange home ranges as one group leaves an area and allows an exudate tree to recover, approximately every few months.

When an area remains unoccupied long enough for a tree to begin producing gum in large amounts again, it is a potential new home range for a different group. Densities of pygmy marmosets are quite high in riverine forests and are up to 233 individuals per km2 (90.0 per mi2). Removed from a river's edge, pygmy marmosets are found in densities closer 50 or 60 individuals per km2 (19.3 or 23.2 per mi2) . With such high densities, home ranges for each group are very small, averaging .003 km2 (.001 mi2) but less than .005 km2 (.002 mi2), and the horizontal day range within these home ranges about 300 m (.186 mi), but they may travel much farther when considering vertical movement within their home range. Home ranges of neighboring groups do not overlap and there are few, if any, interactions between groups.

Because of their extremely small body size, pygmy marmosets are subject to predation by raptors, small felids, and climbing snakes. In some cases, they exhibit mobbing behavior in which the entire group flocks to an intruder, loudly vocalizing and attacking the intruder until it retreats; other times, they remain frozen until the threat has passed.

Diet

Pygmy marmosets are gumophores, which means that they gouge holes in trees and feed primarily on tree sap or gum. They also eat insects, small lizards, spiders, and some fruits. In fact, 67 percent of their feeding time is spent eating tree exudates or preparing new food sources by gnawing tree trunks or large branches, from which they will later collect sap.

Gums are particularly important for pygmy marmosets because their home ranges are so small that they cannot rely on fruit year round. As an adaptation for gnawing, marmosets have long, forward turned, lower incisors that are the same length as their canines; this is the case in all marmosets and is termed the short-tusked condition. (Tamarins, another group of small monkeys, have lower canines that are longer than their lower incisors.) They also have two molars as opposed to three in most other monkeys.

Behaviour

Pygmy marmosets live in groups of about six members, which includes a monogamous male and female and the offspring of up to four litters. Sometimes there are two males, but one is dominant to the other and restricts access to the female. They are diurnal and arboreal, and are capable of jumping vertically up to 5m.

Pygmy marmosets are arboreal and live in extended family groups. They are very agile and active-- running along horizontal or diagonal branches with a galloping gait. They can make long, horizontal leaps of a yard or more and cling or leap vertically. Unfortunately, because of the swift movements, pygmy marmosets are very hard to observe in the wild. When frightened, they clamber up a tree trunk, following a rapid, spiral-like route. They feed on saps and gums, gouging holes in the bark with its specialized incisors. Their small size is well adapted to the marginal energy provided by sap. Pygmy marmosets have a variety of vocalizations, including a trill for communication over distance, a high, sharp warning whistle, and a clicking sound for threats.

Reproduction

Breeding may take place at any time of the year. In the courtship display, the male walks with his body arched, smacking his lips and pushing his tongue in and out.

Nonidentical twins (sometimes triplets) are born twice a year. Male marmosets take excellent care of the young. They carry the babies on their hips and shoulders until the young are about 2 months old, at which time they are independent of both parents. The females care for the young only when nursing or cleaning.

After two months, the young spend their time playing, wrestling and chasing each other and other members of the group. At 6 months, they have reached adult size.

Pygmy marmosets are active during the day. Most activity takes place on cool mornings and in late afternoons. They gallop along branches and can leap three feet or more. They sometimes rest by piercing their nails into the bark of a tree. They sleep at night in hollowed trees or tangled vines.

Conservation

Pygmy marmosets are currently not endangered. However they are listed as special concern or somewhat threatened. Because of their size, mobility and coloration, it is almost impossible to count the pygmy marmosets living in the South American forests. A threat to these small monkeys is the pet trade.

The main predators of the pygmy marmoset are birds of prey. These monkeys are flexible and adapt to environmental changes caused by humans. For example, they have been found living in small groups of trees on the edges of farms that have been created by clear cutting. They have also been known to use secondary forest habitats if there is suitable food available.

Fascinating Facts

• Group members help carry and bring food to the young. Helpers gain parental care skills while they wait for the opportunity to have young of their own!
• The word marmoset is said to be adapted from a French word meaning a grotesque image or mannequin
• An alarmed marmoset turns its head in all directions
• The pygmy marmosets at Woodland Park Zoo are prolific. One of the breeding females had twins every five months. The troop ranges from eight to 10 individuals, with the older offspring of the breeding female and her mate remaining in the group for about two years. As they mature, these offspring are sent to other zoos, where they will mate with other unrelated marmosets
• The small size of the Pigmy Marmoset is great for hiding in the leaves from predators.
• The smallness of this monkey doesn’t keep him from chasing intruders from his territory.
• Pygmy marmosets are only about six inches tall as adults. The tail may add another nine inches. They are gumivores, which means they supplement their diet with the sap, or gum, from certain forest trees.
• They dig a groove in the bark of a tree with specially adapted, shovel shaped incisor teeth. Then they lick out the sap.

Tapirs are large browsing mammals, roughly pig-like in shape, with short, prehensile trunks. They inhabit jungle and forest regions of South America, Central America, and Southeast Asia. All four species of tapir are classified as endangered or vulnerable. Their closest relatives are the other odd-toed ungulates, horses and rhinoceroses.

Looking at a tapir’s small, flexible proboscis (snout and upper lips) and thick, rough skin, the casual observer might think it is a relative of pigs, or related to anteaters or elephants.

Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Perissodactyla
Family: Tapiridae
Genus: Tapirus
Species
Baird's Tapir: Tapirus bairdii
Malayan Tapir: Tapirus indicus
Mountain Tapir: Tapirus pinchaque
Brazilian Tapir:Tapirus terrestris

Amazingly, its closest relatives are the horse and rhinoceros. Similar to their earliest hoofed ancestors, tapirs have four toes on the front feet and three toes on the hind feet. Toes are separated widely, with the middle toes larger than the others. All toes have hooves, and each foot has a callous pad which supports some of the weight.

The front half of the tapir’s body and hind legs is black, and the rear half above the legs is white. This black-and-white pattern obscures its outline, helping the tapir to become practically invisible in its shady forest environment. Lying down in the day, it resembles a large rock. While foraging at night, the tapir blends in with shadows and moonlight, making it difficult for nocturnal predators to detect its presence.

Except for mothers with their young, tapirs are solitary animals. Tapirs have a highly developed sense of smell.

They roam the forest floor and riverbanks at night, noses to the ground, to sniff out food and other tapirs, and to detect the scent of predators. When a tapir smells an appetizing leaf, it uses its short, fleshy proboscis as a sensitive finger to grab and pull the leaf toward its mouth and then moves on.

At first glance, tapirs may look like slow and clumsy animals, and an easy catch for a predator. Nothing can be further from the truth! Tapirs have recessed eyes and short ears, legs and tail. They also have a stocky body that is rounded in back and tapered in front. When threatened, their compact and streamlined shape enables them to crash through the thickest forest underbrush with remarkable speed. They are also excellent divers and swimmers, and seek refuge from predators in deep waterways, where they can remain submerged for several minutes.

If cornered, the thick, hard skin on its neck helps to protect it from a predator’s sharp fangs. Tapirs also have strong jaws and large teeth that can inflict a serious bite.

Species

• Baird's Tapir (Tapirus bairdii)
• Malayan Tapir (Tapirus indicus)
• Mountain Tapir ( Tapirus pinchaque)
• Brazilian Tapir also called Lowland Tapir (Tapirus terrestris)

Baird's Tapir

Baird’s Tapir (Tapirus bairdii) is one of the three species of tapir found in Latin America.

Baird's Tapir: sniffing

Baird's Tapir has a distinctive cream-colored marking on its face and throat and a dark spot on each cheek, behind and below the eye. The rest of its hair is dark brown or grayish-brown. The animal is the largest of the three American species and, in fact, the largest land mammal found in the wild from Mexico to South America. Baird’s Tapirs usually grow to 2 meters in length (6.5 feet) and 1.2 meters (4 feet) in height, and adults weigh between 240 and 400 kilograms (525 and 880 pounds). Like the other types of tapir, they have small stubby tails and long, flexible proboscises. They have four toes on each front foot and three toes on each back foot.

It is named for the American naturalist W. M. Baird who traveled to Mexico in 1843 and observed the animals. However, the species was first documented by another American naturalist, W. T. White.

Malayan Tapir

The Malayan Tapir (Tapirus indicus), also called the Asian Tapir, is the largest of the four species of tapir and the only one native to Asia. The scientific name is somewhat misleading, as the Tapirus indicus is not native to India; the name refers rather to the East Indies.

The animal is easily identified by its markings, most notably the light-colored “saddle” which extends from its shoulders to its rump. The rest of its hair is black, except for the tips of its ears which, as with other tapirs, are rimmed with white. This pattern is for camouflage: the disrupted coloration makes it more difficult to recognize it as a tapir, and other animals may mistake it for a large rock rather than a form of prey when it is lying down to sleep.

Malayan Tapirs grow to between 6 and 8 feet (1.8 to 2.4 m) in length, stand 3 to 3.5 feet (90 to 107 cm) tall, and typically weigh between 550 and 700 pounds (250 to 320 kg), although they can weigh upwards of 900 pounds (410 kg) on occasion.

A female tapir with proboscis outstretched, Woodland Park Zoo, Seattle

The females are usually larger than the males. Like the other types of tapir, they have small stubby tails and long, flexible proboscises. They have four toes on each front foot and three toes on each back foot. The Malayan Tapir has rather poor eyesight but excellent hearing and sense of smell.

Mountain Tapir

The Mountain Tapir (Tapirus pinchaque) is the smallest of the four species of tapir and is the only one to live outside of tropical rainforests in the wild.

Mountain Tapir

The Mountain Tapir is referred to as Sacha Huagra by Quechua speakers, danta cordillerana (cordilleran tapir) and danta lanuda (woolly tapir) by Spanish-speakers in Colombia, danta negra (black tapir) by Spanish-speaking Ecuadorians, and tapir de altura (tapir of the heights) or gran bestia (large beast) by Spanish-speaking Peruvians.

The species name comes from the term "La Pinchaque", an imaginary beast said to inhabit the same regions as the Mountain Tapir

The Mountain Tapir is most easily recognized by its wooly coat (it is sometimes referred to as the wooly tapir) and its white lower lip. Mountain Tapirs may have greyish-black or brown coats, often depending on where they live, and often the hair around their cheeks is lighter.

Adults are usually around 1.8 meters (6 feet) in length and 0.75 to 1 meter (2.5 to 3 feet) in height. They typically weigh between 150 and 225 kilograms (325 to 500 pounds). The females are more often larger than the males, but usually the sexes are indistinguishable by size. Like the other types of tapir, they have small stubby tails and long, flexible proboscises. They have four toes on each front foot and three toes on each back foot.

Brazilian Tapir

The Brazilian Tapir (anta in Portuguese), also known as the Lowland Tapir (Tapirus terrestris) is one of four species in the tapir family, along with the Mountain Tapir, the Malayan Tapir, and the Baird's Tapir.

It is dark brown in color and has a low, erect mane running from the crown down the back of the neck. The Brazilian Tapir can attain body lengths of 1.80 to 2.50 m with a 5 to 10 cm long tail and 270 kg in weight. It stands somewhere between 77 to 108 cm at the shoulder.

Brazilian Tapir

Tapirus terrestris is 77 to 108cm [30 to 43 in.] at the shoulder. The total body length of females ranges to 221cm [just over 7 ft.], and of males to 204cm [6 ft., 7 in.]. The tail is a short stump of approximately 8cm. The hindfeet have three hooved toes and the forefeet have an additional, much reduced, fourth toe. Coloration varies from tan to black or red. The undersides and short legs are generally dark and the cheeks, throat, and ear edges are often lighter in color. A black mane extends from the forehead to the midback. One of the most distinguishable characteristics of the Brazilian tapir is its proboscis, which is long, flexible, prehensile, and covered with sensory vibrissae. A tall sagittal crest makes the head appear convex. Females have a single pair of mammary glands. Young are colored quite differently from the adults; they are dark brown and have white spots and stripes.

Hybrids

Hybrid tapirs from the Baird's Tapir and the Brazilian Tapir were bred at the San Francisco Zoo around 1968 and produced a second generation around 1970.

Brazilian Tapirs are often seen swimming in the many rivers of Iwokrama Forest.

Physiology

exhibit the flehmen response, a posture in which they raise their snouts and show their teeth, in order to detect scents. This response is frequently exhibited by bulls sniffing for signs of other males or females in oestrus in the area. Proboscis length varies among species; Malayan Tapirs have the longest snouts and Brazilian Tapirs have the shortest. The evolution of tapir probosces, made up almost entirely of soft tissues rather than bony internal structures, gives the Tapiridae skull a unique form in comparison to other perissodactyls, with a larger sagittal crests, orbits positioned more rostrally, a posteriorly telescoped cranium, and a more elongated and retracted nasoincisive incisure

Tapirs have brachyodont, or low-crowned, teeth that lack cement. Their dental formula is I 3/3, C 1/1, P 4/3-4, M 3/3, totaling 42 to 44 teeth; this dentition is closer to that of equids, who may differ by one less canine, than their other perissodactyl relatives, rhinoceroses. Their incisors are chisel-shaped, with the third large, conical upper incisor separated by a short gap from the considerably smaller canine.

A much longer gap is found between the canines and premolars, the first of which may be absent. Tapirs are lophodonts, and their cheek teeth have distinct lophs (ridges) between protocones, paracones, metacones and hypocones.

Tapirs have brown eyes, often with a bluish cast to them which has been identified as corneal cloudiness, a condition most commonly found in Malayan Tapirs. The exact etiology is unknown, but the cloudiness may be caused by excessive exposure to light or by trauma. However, the tapir's sensitive ears and strong sense of smell help to compensate for deficiencies in vision

Baby Brazilian Tapir.

Natural history

The tapir family is old by mammalian standards: the earliest fossil tapir dates to the early Oligocene, and Eocene rocks from as early as 55 million years ago contain a wide range of tapir-like animals. These ungulates could be found world-wide. Perissodactyls, including tapiroids, became the predominant large terrestrial browsers through the Oligocene, and many members of the group survived until the late Pleistocene. It is believed that Asian and American tapirs diverged around 20 to 30 million years ago, and that tapir varieties moved from North America to Central and South America around 3 million years ago.

Baby Mountain Tapir.

Lifecycle

Young tapirs reach sexual maturity between three and five years of age, with females maturing earlier and coming into oestrus every two or three months. Under good conditions, a healthy female tapir can reproduce every two years, giving birth to a single youngster is born after a gestation of about 13 months. The natural lifespan of a tapir is approximately 25 to 30 years, both in the wild and in zoos. Little is known for sure about tapirs’ mating patterns in the wild: there is some evidence that mature tapirs mate with the same partner for life, but pairs spend little or no time together aside from sexual activity. Apart from mothers and their young offspring, tapirs lead almost exclusively solitary lives.

Behavior

Although they frequently live in dryland forests, tapirs with access to lakes or rivers spend a good deal of time in and under the water, feeding on soft vegetation, taking refuge from predators, and cooling off during hot periods. Tapirs near a water source will swim, sinks to the bottom and walks along the riverbed to feed, and have been known to submerge themselves under water to allow small fish to pick parasites off their bulky bodies. Along with fresh water lounging, tapirs often wallow in mud pits, which also helps to keep them cool and free of insects.

In the wild, the tapir’s diet consists of fruit, berries, and leaves, particularly young, tender growth. Tapirs will spend many of their waking hours foraging along well-worn trails, snouts to the ground in search of food. Baird’s Tapirs have been observed to eat around 40 kilograms (85 pounds) of vegetation in one day.

Tapirs are largely nocturnal and crepuscular, although the smaller Mountain Tapir of the Andes is generally more active during the day than its congeners.

Habitat, predation, and vulnerability

Adult tapirs are large enough that they have few natural predators, and the thick skin on the backs of their necks helps to protect them from threats such as jaguars, crocodiles, anacondas, and tigers. The creatures are also able to run fairly quickly, considering their size and cumbersome appearance, finding shelter in the thick undergrowth of the forest or in water. However, tapirs have no reliable defense against humans, by far the greatest threat to their survival. Hunting for meat and hides has substantially reduced their numbers and, more recently, massive habitat loss has resulted in the conservation watch-listing of all four species: both the Brazilian Tapir and the Malayan Tapir are classified as vulnerable; and the Baird’s Tapir and the Mountain Tapir are endangered. Tapirs tend to prefer old growth forests and the food sources that can be found in them, making the preservation of primary woodlands a top priority for tapir conservationists.

The Malayan tapir, the species most isolated geographically from the rest of the genus, has a significantly smaller number of chromosomes and has been found to share fewer homologies with the three types of American tapirs. A number of conserved autosomes (13 between karyotypes of the Baird’s Tapir and Brazilian Tapir, and 15 between the Baird’s and Mountain Tapir) have also been found in the American species that are not found in the Asian animal.

However, geographic proximity is not an absolute predictor of genetic similarity; for instance, G-banded preparations have revealed that Malayan, Baird’s and Brazilian Tapirs have identical X chromosomes, while Mountain Tapirs are separated by a heterochromatic addition/deletion.

Lack of genetic diversity in tapir populations has become a major source of concern for conservationists. Habitat loss has isolated already small populations of wild tapirs, putting each group in greater danger of dying out completely. Even in zoos, genetic diversity is limited; all captive mountain tapirs, for example, are descended from only two founder individuals.

Attacks on humans

Tapirs are generally shy, but when they are scared they can defend themselves with their very powerful jaws. In 1998, a zookeeper in Oklahoma City was mauled and had an arm severed by a tapir bite, after she attempted to feed the attacking tapir's young.

In 2006, a 46-year-old man who was lost in the Costa Rican jungle was found by a search party with a "nasty bite" from a wild tapir. However, such examples are rare; for the most part, tapirs are likely to avoid confrontation in favor of running from predators, hiding, or, if possible, submerging themselves in nearby water until a threat is gone.

Fascinating Facts

• The heaviest tapir on record weighed 1,190 pounds!
• The Malayan tapir supposedly can walk on a river bottom like the hippopotamus!
• Tapirs have changed little in appearance in the past 20 million years!
• Tapirs are the largest native mammal on the South American continent.

The orangutans are two species of great apes with long arms and reddish, sometimes brown, hair native to Malaysia and Indonesia. They are the only extant species in the genus Pongo and the subfamily Ponginae, although that subfamily also includes the extinct Gigantopithecus and Sivapithecus genera. The orangutan is an official state animal of Sabah in Malaysia.Their name in malaysian means Man of the Woods.

Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Family: Hominidae
Subfamily: Ponginae
Genus: Pongo
Type Species: Simia pygmaeus
Species: Pongo pygmaeus, Pongo abelii

Orangutans are the most arboreal of the great apes, spending nearly all of their time in the trees, making a new nest in the trees every night. Adult males are about 4.5 ft (1.4 m) tall and up to 180 lb (82 kg) in weight. They are only found in rainforests on the islands of Borneo and Sumatra. These two small isolated populations were classified as subspecies until recently, when they were elevated to full specific level.

Orangutans are highly endangered in the wild. Orangutan habitat destruction due to logging, mining and forest fires has been increasing rapidly in the last decade. Much of this activity is illegal, occurring in national parks that are officially off limits to loggers, miners and plantation development. There is also a major problem with the illegal trapping of baby orangutans for sale into the pet trade; the trappers usually kill the mother to steal the baby.

Like the other great apes, orangutans are remarkably intelligent. Although tool use among chimpanzees was documented by Jane Goodall in the 1960s, it wasn't until the mid-1990s that one population of orangutans was found to use feeding tools regularly. A 2003 paper in the journal Science described the evidence for distinct orangutan cultures.

Although orangutans are generally passive, aggression towards other orangutans is very common; they are solitary animals and can be fiercely territorial. Immature males will try to mate with any female, and may succeed in forcibly copulating her (rape) if she is also immature and not strong enough to fend him off. Mature females easily fend off their immature suitors, preferring to mate with a mature male. Wild orangutans are known to visit human-run facilities for orphaned young orangutans released from illegal captivity, interacting with the orphans and probably helping them adapt in their return to living in the wild.

Orangutans are highly intelligent with an ability to reason and think. This large, gentle red ape is one of our closest relatives, sharing 97% of the same DNA as humans. Indigenous peoples of Indonesia and Malaysia call this ape "Orang Hutan" literally translating into English as "People of the Forest". In times past they would not kill them because they felt the orangutan was simply a person hiding in the trees, trying to avoid having to go to work or become a slave.

Orangutans are unique in the ape world. There are four kinds of great apes: gorillas, chimpanzees, bonobos and orangutans. Only the orangutan comes from Asia; the others all come from Africa. There are two separate species of orangutan - the Sumatran orangutan (Pongo abelii) and the Bornean orangutan (Pongo pygmaeus)

The orangutan is the only strictly arboreal ape and is actually the largest tree living mammal in the world. The rest of the apes do climb and build sleeping nests in the trees, but are primarily terrestrial (spending their lives on the ground). Even the hair color of the orangutan, a bright reddish brown, is unique in the ape world.

The orangutan has the most remarkable ability to travel through the forest treetops. They make their home in these trees and build nests each night out of leaves and branches in the very tops of the trees.

This is where they live and sleep - sometimes as much as 100 feet above the ground. The orangutan has little need to come down from the trees, as they are uniquely adapted for their arboreal lifestyle.

Almost all of the food they eat grows in the treetops and the frequent rains fill the leaves thus supplying their drinking water. When water is difficult to get, they chew leaves to make a sponge to soak up water in tree cavities. When it rains very hard the orangutan makes an umbrella for himself out of big leaves. Many people are familiar with the studies that have shown chimpanzees using tools, such as termite-fishing sticks. Recent studies show that some populations of orangutans also fashion tools to aid in the difficult task of foraging for food.

Some might say orangutans have four hands instead of two hands and two feet. This makes them graceful and agile while climbing through the trees but it makes walking on the ground somewhat slow and awkward.

That is why the orangutan is at a great disadvantage on the ground, and why the orangutan rarely comes down from the treetops. Their food is there, their home is there and they are safer there.

An orangutan's lifespan is about 35-40 years in the wild, and sometimes into the 50's in captivity. They reach puberty at about 8 years of age, but a female isn't ready for her own baby until she's in her teens.

The orangutan has the longest childhood dependence on the mother of any animal in the world, because there is so much for a young orangutan to learn in order to survive. The babies nurse until they are about six years of age. The young males may stay close by their mothers for a few more years but the females may stay until they are into their teens, allowing them to observe mothering skills as they watch their younger sibling being raised by the mother. Orangutan females only give birth about once every 8 years - the longest time between births of any mammal on earth. (This results in only 4 to 5 babies in her lifetime.) This is why orangutan populations are very slow to recover from disturbance.

Food is often scarce in the rain forest and that is why the orangutan is a semi-solitary creature. In times of great abundance of food, orangutans may use the opportunity to socialize and gather in small groups.

Diet

Their diet is made up of bark, leaves, flowers, a variety of insects, and most importantly, over 300 kinds of fruit. The mothers must teach the babies what food to eat, where to find that food, in which trees and during which seasons. It is thought that the orangutan must have a very detailed map of the forest in her mind, and detailed knowledge of the fruiting cycles of many species of trees. (This prevents wasting valuable energy searching for fruit trees randomly, and traveling to a certain fruiting tree whose fruits will not ripen for some time).

The babies must eventually know hundreds of species of plants and trees, which ones are edible, and how to process them; some are very difficult to eat because they are protected by sharp spines and shells.

Terminology

The word orangutan (also written orang-utan, orang utan and orangutang) is derived from the Malay orang hutan meaning man of the forest, although local people do not use this term to refer to orangutans. Maias and mawas are also used in Malay, but it is unclear if those words refer only to orangutans, or to all apes in general.

The word was first attested in the form orang-outang, and variants with -ng instead of -n as in the Malay original are found in many languages. This spelling (and pronunciation) has remained in use in English up to the present, but has come to be regarded as incorrect by some, e.g. However, dictionaries such as the American Heritage Dictionary regard forms with -ng as acceptable variants.

The name of the genus, Pongo, comes from a 16th century account by Andrew Battell, an English sailor held prisoner by the Portuguese in "Angola" (probably somewhere near the mouth of the Congo River), which describes two anthropoid "monsters" named Pongo and Engeco. It is now believed that he was describing gorillas, but in the late 18th century it was believed that all great apes were orangutans; hence Lacépède's use of Pongo for the genus

Habitat

Ten thousand years ago, orangutans were found throughout Southeast Asia ranging all the way into southern China. Their populations probably numbered in the hundreds of thousands. Today, however, the few orangutans left live in the tropical rainforests of Borneo and Sumatra.

Indonesia’s forests represent 10% of the world’s remaining tropical forests with an area of 260 million acres. According to the European League, by 2001 Indonesia has lost 99 million acres of forest in the last 32 years, which is equivalent to the combined size of Germany and the Netherlands. In total, Indonesia has lost 80% of its original forest habitat and continues to lose 6.2 million acres a year.

Indonesia is one of the five most species-diverse countries in the world, with 12% of all mammal species, 16% of reptile and amphibian species, and 17% of bird species. Of these, 772 are threatened, giving Indonesia the third highest number of threatened species, falling behind Malaysia and the United States. Of Indonesia’s approximately 40 primate species, 20 were found to have lost more than half their original habitat in the last 10 years.

Anatomy

Orangutans have a large, bulky body, a thick neck, very long, strong arms, short, bowed legs, and no tail. Orangutans are about 2/3 the size of the gorilla.
Hair: They are mostly covered with long reddish-brown hair.
The Head: The orangutan has a large head with a prominent mouth area. Adult males have large cheek flaps (which get larger as the ape ages).
Senses: Orangutans have senses very similar to ours, including hearing, sight, smell, taste, and touch.
Hands and Feet: Orangutan hands are very much like ours; they have four long fingers plus an opposable thumb. Their feet have four long toes plus an opposable big toe. Orangutans can grasp things with both their hands and their feet. The largest males have an arm span of about 7.5 feet (2.3 m).

Culture

Not long ago, many people thought culture was unique to the human species, but in recent years, scientists are finding increasing evidence of socially learned traditions elsewhere in the animal kingdom. In January 2003, a group of researchers, including primatologist Dr. Carel van Schaick of Duke University and OFI’s president, Dr. Biruté Mary Galdikas, described two dozen behaviors that are present in some orangutan groups and absent in others. According to the report, these practices are learned from other group members and passed down through the generations. In parts of Borneo, for example, orangutans use handfuls of leaves as napkins, wiping leftover food from their chins.

Orangutans in parts of Sumatra, conversely, use leaves as gloves, helping them handle spiny fruits and branches, or as seat cushions in spiny trees.

Behaviour

Orangutans are diurnal animals, spending a large portion of daylight hours searching for and consuming food. Most of their lives are spent in trees where they travel from branch to branch by climbing, clambering, and brachiating. Usually each night, a new nest for sleeping is constructed from branches and built 15 to 100 feet up in a tree. Although mostly arboreal, males will occasionally come to the ground to move between stands of trees. While females stay near their mothers’ home ranges, males emigrate long distances. This helps minimize inbreeding within populations.

In the wild, orangutans have been observed making simple tools to scratch themselves. They also use leafy branches to shelter themselves from rain and sun, and sometimes even drape large leaves over themselves like a poncho. They have also been observed using branches as tools during insect foraging, honey collection, and protection against bees, and to fish for branches or fruit that is out of reach.

Adult male orangutans usually keep a considerable distance between one another; their participation in social groups is usually limited to temporary sexual "consortships" with adult and adolescent females. Adult females may be seen with their young, with adult females, and with adolescents who are not necessarily their own. The mother-young relationship lasts for many years, whereas the time spent with non-related orangutans is relatively short. Sub-adult males usually associate with females. Adolescent females travel together when age differences are minimal. This semi-solitary social system may have evolved as a result of the scattered food distribution and a lack of large predators.

Whereas the female orangutan can often remain sexually passive, a male must pursue his reproductive interest, using his pendulous laryngeal sac for the "long call," parts of which sound like a loud roar. The male orangutan’s call plays an important role in repelling male rivals and advertising his availability to sexually receptive females, helping him to compete aggressively with other adult males. Thus, mature male orangutans appear to be intolerant of each other, and the meeting of two mature males usually results in either aggression or avoidance.

Adaptations

Male orangutans are approximately twice the size of females, weighing up to 300 pounds and reaching a height of 5 feet. The male’s larger size may be an adaptation for mating, as strong competition among males for females tends to promote this type of sexual dimorphism. The orangutans’ long, narrow hands and feet are especially useful for grasping branches. Their opposable thumbs and big toes are short to facilitate the hook-like function of their hands and feet.

Conservation

Orangutans are an endangered species according to most wildlife monitoring organizations and conservation groups. Ten thousand years ago, orangutans were found throughout Southeast Asia ranging all the way into southern China. Their populations probably numbered in the hundreds of thousands.

Unfortunately, the species today is found only in limited populations on the islands of Borneo and Sumatra. Due to the destructive activities of humans, the wild population may have diminished in the past decade by as much as 50%. Estimates of the current population are from less than 50,000 to 60,000 with more than three quarters of all orangutans found on Borneo.

The destruction and degradation of the tropical rain forest, particularly the lowland forests, is the main reason orangutans are threatened. This has been caused primarily by human activity (intense permitted logging, illegal logging, conversion to palm oil plantations and farm lands, mining, settlements, road construction) and also by natural phenomena (large-scale fires). Additionally, the illegal animal trade has been a significant factor in the decline the wild orangutan population. Finally, orangutans are occasionally hunted and eaten by some of the indigenous peoples of Borneo as well as immigrant loggers who do not have a dietary prohibition to eating primate bushmeat.

Fun Facts!

• In Malay orang means "person" and utan is derived from hutan, which means "forest." Thus, orangutan literally means "person of the forest."
• Orangutans’ arms stretch out longer than their bodies - over 7 ft. from fingertip to fingertip - and are used to employ a "hookgrip." When on the ground, they walk on all fours, using their palms or their fists.
• When male orangutans are about 15 years old, they develop large cheek pads, which female orangutans apparently find attractive.
• When males are fighting, they charge at each other and break branches. If that doesn’t scare one of them away, they grapple and bite each other.
• For the first few years of his/her life, a young orangutan holds tight to his/her mother’s body as she moves through the forest in search of fruit. Later, he/she will follow the mother as she moves through the trees.
• Like humans, orangutans have opposable thumbs. Their big toes are also opposable.
• Orangutans have tremendous strength, which enables them to brachiate (swing from branch to branch) and hang upside-down from branches for long periods of time to retrieve fruit and eat young leaves.

The orca (Killer whale) is the largest member of the oceanic dolphin family Delphinidae. They are traditionally referred to as blackfish, a group including pilot whales, pigmy and false killer whales and melon headed whales. It is the second-most widely distributed mammal on Earth (after humans) and is found in all the world's oceans, from the frigid arctic regions to warm, tropical seas.

Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Cetacea
Family: Delphinidae
Genus: Orcinus
Species: O. orca
Binomial name: Orcinus orca

It is also a versatile, deadly predator, eating fish, turtles, birds, seals, sharks and even other juvenile and small cetaceans. This puts the orca at the pinnacle of the marine food chain. The orca also attacks whales, in particular gray whales.

The name "killer whale" reflects the animal's reputation as a magnificent and fearsome sea mammal that goes as far back as Pliny the Elder's description of the species. Today it is recognized that the orca is a dolphin rather than a whale and that it is not a danger to humans. Aside from a boy who was charged (but not grabbed) while swimming in a bay in Alaska, there have been no confirmed attacks on humans.

There have, however, been isolated reports of captive orcas attacking their handlers at marine theme parks.

The species has adapted to living in a variety of environments from tropical to polar seas and the list of known prey types is impressive varying from schooling fish to large whales. However, killer whale populations do not behave as generalists but specialize on certain types of prey. The prey choice is of central importance to the behaviour, habitat use and distribution pattern of the different killer whale populations. In Norwegian waters Norwegian spring spawning herring is the main type of prey for killer whales. Killer whales occurring in the coastal waters of Iceland feed also on herring and there are several similarities in the behaviour of Icelandic and Norwegian killer whales.

Killer whales are sexually dimorphic, meaning that it is possible to distinguish between mature males and females based on their appearance. The largest killer whale male which has been measured was 9.6 meters long, the longest female 8, 2 meters long. The average length of Norwegian killer whale males is 7 meters, of females 5,5 meters. In addition to their larger body size, adult males have a taller dorsal fin than females.

Common to all killer whales is that they live in groups; single killer whales are rarely sighted. Again, the group size and stability varies among the populations. The most common social organisation among killer whales consists of matrilineal, stable family groups. In practice this means that killer whales of both sexes stay in the group they were born into throughout their lives! So the large adult males in a group are not the fathers of the calves, but rather their uncles or big brothers. Another remarkable aspects of these stable matriarchal groups, is that each family has its own vocal dialect. Long term photoidentification studies of killer whales in Norway have shown that also here the killer whales live in stable family groups.

Orcas often raise their body out of the water in a behaviour called spyhopping. Scientists debate its purpose.

Mating does not occur within the groups. Killer whale gestation period is estimated to be 16 months. The Norwegian killer whales have a peak in calving in late fall (November-December) and therefore mating season should be in late summer. Killer whale females get sexually mature at about 13-15 years old and they get one calf every 3-5 years. The females stop breeding when they are about 40 years old but continue to live several years, even decades after their last calf has been born. The old matriarchs have an important function in the groups where much of the behaviour is learned.

Naming

The name "orca" (plural "orcas") was originally given to these animals by the ancient Romans, possibly borrowed from the Greek word ???? which (among other things) referred to a species of whale.

The term "orc" (or its variant "ork") has historically been used to describe a large fish, whale or sea-monster. It is now considered an obsolete equivalent for "orca."

The name "killer whale" is widely used in common English. However, since the 1960s, "orca" has steadily grown in popularity as the common name to identify the species, and both names are now used - leading to confusion. The species is called orca in most other European languages, and, as there has been a steady increase in the amount of international research on the species, there has been a convergence in naming.

Taxonomy and evolution

The orca is the sole species in the genus Orcinus. It is one of thirty-five species in the dolphin family. Like the Sperm Whale genus Physeter, Orcinus is a genus with a single, abundant species with no immediate relatives from a cladistic point of view, thus palaeontologists believe that the killer whale is a prime candidate to have an anagenetic evolutionary history

— that is the evolution of ancestral to descendant species without splitting of the lineage. If true, this would make the orca one of the oldest dolphin species, although it is unlikely to be as old as the family itself, which is known to date back at least five million years.

Three distinct populations

Modern research indicates that there are three distinct population types or classifications of orcas off the western coastline of North America. While each looks similar, they have distinct genetic differences, food preferences, and habits. These are the called the transient, resident and offshore types.

Transient attacking a sea lion

Transient

Transient orcas generally travel in small groups, usually up to 7 or 8 animals. These are referred to as groups rather than pods because they do not have as strong a social bond, and do not necessarily remain as a family unit, probably due to their diet. They are generally seen cruising along the shorelines hunting for prey. It is this group’s ruthless hunting and eating habit that gained orca the nick name "killer whales."

Often, to avoid injury, they will disable their prey before killing and eating it. This may involve throwing it in the air, slapping it with their tails, ramming it, or breaching and landing on it. The whole process can be quite lengthy at times, seeming to be like torture for the prey, but is primarily for safety and training for the young killer whales. Female transients are characterized by pointed dorsal fin tips. The range for transient killer whales is unknown, but may be as much as 1500 miles or more.

Resident

Resident orcas are the most commonly sighted of the populations, often observed in coastal waters. Female residents characteristically have a rounded dorsal fin tip that terminates in a sharp corner. While nomadic, their range is much smaller, and they are known to visit certain areas consistently. The resident orca’s diet consists primarily of fish, including salmon and herring and they frequent areas where their preferred fish are abundant.

They are continually on the move, sometimes traveling as much as 100 miles in a day, but may be seen in a general area for a month or more. Range for resident killer whale pods may be as much as 800 miles or as little as 200 miles. Resident orcas live in complex and cohesive family groups known as pods. Resident pods are generally larger than the transient and offshore pods, having up to 50 or more members. Several pods occasionally join to form what are referred to as superpods, sometimes numbering in excess of 150 animals. On November 15, 2005 the United States government listed the Southern Resident population of killer whales as an endangered species under the Endangered Species Act (ESA) due to deterioration of the three pods which spend most of the year in Georgia and Haro Straits, as well as Puget Sound in British Columbia and Washington state.

Offshore killer whales

Offshore

Offshore orcas were given this name for what the name implies. They remain offshore cruising the open oceans feeding primarily on fish. They have been seen traveling in groups of up to 60 animals. Currently there is little known about the habits of this population, but they can be distinguished genetically from the residents and transients. Female offshores are characterized by dorsal fin tips that are continuously rounded.

Physical characteristics

The animals are distinctively marked, with a black back, white chest and sides and a white patch above and behind the eye. They have a heavy and stocky body and a large dorsal fin with a dark gray "saddle patch" behind it. Males can be up to 9.5 m long (31 ft) and weigh in excess of 6 tons; females are smaller, reaching up to 8.5 m (28 ft) and a weight of about 5 tons. Calves at birth weigh about 180 kg and are about 2.4 m long (8 ft).

Unlike most dolphins, the pectoral fin of an orca is large and rounded — more of a paddle than other dolphin species. Pectoral fins of males are significantly larger than those of females. At about 1.8 m (6 ft), the dorsal fin of the male is more than twice the size of the female's, and is more of a triangle shape — a tall, elongated isosceles triangle, whereas the dorsal fin of the female is shorter and generally more curved.

Nicks, cuts and scrapes on these fins, as well as distinctive features of each fin, help scientists identify individuals. There are also minor variations in physical characteristics between resident and transient Killer Whales.

Large male orcas are very distinctive and are unlikely to be confused with any other sea creature. When seen from a distance in temperate waters, females and juveniles can be confused with various other species, such as the false killer whale or Risso's dolphin. Most life history data about orcas has been obtained from long-term surveys of the population off the coasts of British Columbia and Washington and by monitoring captive orcas.

Due to the completeness of the study and highly structured nature of the pods in this population, the information is detailed and accurate; however, transient groups and groups in other oceans may have slightly different characteristics. Females become mature at around 15 years of age. From then they have periods of polyestrous cycling with non-cycling periods of between three and sixteen months. The gestation period varies from fifteen to eighteen months. Mothers calve, with a single offspring, about once every five years. In analysed resident pods, birth occurs at any time of year, with the most popular months being those in winter. New-born mortality is very high — one survey suggested that nearly half of all calves fail to reach the age of six months.

Calves nurse for up to two years, but will start to take solid food at about twelve months. Cows breed until the age of 40, meaning that on average they raise five offspring. Typically females live to the age of fifty, but may survive well into their eighties or nineties in exceptional cases. Males become sexually mature at the age of 15, but do not typically reproduce until age 21. Males live to about 30 on average, and to 50 in exceptional cases.

Range

The orca is the second-most widely distributed mammal in the world, after the human. They are found in all oceans and most seas including (unusual for cetaceans) the Mediterranean and Arabian Seas. Cooler temperate and polar regions are preferred, however. Although sometimes spotted in deep water, coastal areas are generally preferred to pelagic environments.

Information for off-shore regions and tropical waters is more scarce but widespread, if not frequent; sightings indicate that the orca can survive in most water temperatures. Sightings are rare in Indonesian and Philippine waters. No estimate for the total worldwide population exists. Local estimates include 70-80,000 in the Antarctic, 8,000 in the tropical Pacific (although tropical waters are not the orca's preferred environment, the sheer size of this area — 19 million square kilometres — means there are thousands of orcas), up to 2,000 off Japan, 1,500 off the cooler northeast Pacific and 1,500 off Norway. Adding very rough estimates for unsurveyed areas, the total population could be around 100,000.

Social interaction

Fish-eating orcas in the North Pacific have a complex system of social grouping. The basic unit is the matriline, which consists of a single female (the matriarch) and her descendants. The sons and daughters of the matriarch form part of the line as do the sons and daughters of those daughters (the sons and daughters of the sons join the matriline of their mates) and so on down the family tree.

Because females can live for up to ninety years, it is not uncommon for four or even five generations to travel together. These matrilineal groups are highly stable over many years. Individuals will only split off from their matrilineal group for up to a few hours at a time in order to mate or forage. No permanent casting out of an individual from a matriline has ever been recorded. The average matriline size as recorded in northeast Pacific waters is nine animals.

Matrilines form loose aggregations called pods, consisting on average of about 18 animals. Members of a pod all have the same dialect (see the section on vocal behaviour below) and consist of closely related matriline fragments. Unlike matrilines, pods will split apart for days or weeks at a time in order to carry out foraging before joining back together. The largest recorded pod is 49 animals.

The final layer of association, perhaps more arbitrary and devised by humans rather than the other very natural divisions, is called the community and is loosely defined as the set of clans that are regularly seen mixing with each other. Communities do not follow discernible familial or vocal patterns.

Diet

The orca is an apex predator and the array of species on which orcas prey is extremely diverse. Specific populations show a high degree of specialization on particular prey species. For example, some populations in the Norwegian and Greenland sea specialise on herring and follow that fish's migratory path to the Norwegian coast each autumn. Other populations in the area prey on seals.

The orca is the only cetacean species to regularly prey on other cetaceans. Twenty-two species have been recorded as preyed on, either through an examination of stomach contents, examining scarring on the other cetacean's body, or by simply observing the feeding activity. Groups of orcas will even prey on larger cetaceans such as minke whales, gray whales, female and juvenile sperm whales or young blue whales. A group of killer whales take a young whale by chasing it and its mother through the sea, wearing them out.

Eventually the orcas manage to separate the pair and surround the young whale, preventing it from returning to the sea's surface to breathe. Large whales are typically killed by drowning in this way.

There has also been one recorded case of probable orca cannibalism. A study carried out by V. I. Shevchenko in the temperate areas of the South Pacific in 1975 recorded two male orcas whose stomachs contained the remains of other orcas. Of the 30 orcas captured and examined in this survey, 11 had empty stomachs — an unusually high percentage which indicates the orcas were forced to cannibalism through a lack of food. The diet of killer whales shows substantial variation among different populations. Fish-eating populations prey on 30 species of fish, particularly salmon (including chinook and coho), herring, and tuna. Basking sharks, oceanic whitetip sharks, and very occasionally even great white sharks are taken for their nutrient-rich livers. Other marine mammals, including most species of seal and sea lion, are taken by mammal-eating populations. Walrus and sea otters are taken less frequently. Several species of bird are also taken, including penguins, cormorants and sea gulls. Cephalopods, such as octopuses and a wide range of squids, are also targets.

Possessing great physical prowess as well as intelligence, Orcas use complex hunting strategies to find and subdue their prey. They sometimes will throw seals to one another through the air in order to stun and kill the animal. While salmon are usually hunted by a single orca or a small group of individuals, herring are often caught using carousel feeding:

the orcas force the herring into a tight ball by releasing bursts of bubbles or flashing their white underside. The orcas then slap the ball with their tail flukes, either stunning or killing up to 10-15 herring with a successful slap. The herring are then eaten one at a time. Carousel feeding has only been documented in the Norwegian orca population and with some oceanic dolphin species. Sea lions are killed by head-butting or by being slapped and stunned by a tail fluke.

Co-operating with humans

More unusally, Orca have also be known to co-operate with humans in the hunting of other whales. One famous incidence of this was near the port of Eden in South-Eastern Australia in the 1920s. A pod of Orca, led by a dominant male called Old Tom, would assist whalers in hunting baleen whales - the Orca would find the target whales, shepherd them into Twofold Bay and then alert the whalers to their presence and often help to kill the whales. In return the whalers allowed the orcas to eat the tongue and lips of the whale before hauling it ashore.

Captivity

The orca's intelligence, trainability, striking appearance, playfulness in captivity, and its sheer size have made it a popular exhibit at aquariums and various aquatic theme parks. The first orca capture and display took place in Vancouver in 1964. Over the next 15 years around sixty or seventy orcas were taken from Pacific waters for this purpose.

In the late 1970s and the first half of the 1980s, orcas were generally taken from Icelandic waters (fifty in the five years to 1985). Since that time, orcas have been successfully bred in captivity and wild specimens are considerably rarer. Orcas in captivity may develop pathologies such as dorsal fin collapse, seen in 60-90% of captive males.

There have been incidents with orcas in captivity attacking humans. In 1991, a group of orcas killed a trainer named Keltie Byrne at Sealand in Victoria, British Columbia (where employees were not allowed in the water with orcas), apparently not knowing she could not survive underwater. In 1999, at the SeaWorld park in Orlando, Florida, one of the same orcas allegedly killed a tourist who had snuck into the orca's pool at night. (The dead tourist, who was otherwise physically unharmed, was also thought to be a victim of hypothermia.) In late July 2004, during a show at the SeaWorld park in San Antonio, Texas, an orca pushed its trainer of ten years underwater and barred the way to the rim of the pool; the trainer could only be rescued from the raging animal after several minutes.

One of the more infamous incidents involving orca aggression took place in August 1989, when a dominant female orca, Kandu V, struck a newcomer orca, Corky II, with her mouth during a live show. Corky II had been imported from Marineworld California just months prior to the incident. According to reports, a loud smack was heard across the stadium.

Although trainers tried to keep the show rolling, the blow severed an artery near Kandu V's jaw, and she began spouting blood. The crowd was quickly ushered out, and after a 45-minute hemorrhage, Kandu V died. Opponents of these shows see these incidents as supporting their criticism.

Conservation

Up until 25 years ago, killer whales were widely feared and largely misunderstood. Fishermen and mariners often shot them on sight. With the introduction of killer whales into aquariums and oceanariums in the 1960's and 70's, public interest and a better understanding of these animals grew. They were no longer thought of as ferocious beasts but rather as intelligent and inquisitive creatures. Today, however, we are threatening them in new ways. Increasing boat traffic, over-fishing, pollution and other human activities all potentially threaten whales and their fragile environmen.

Hunting

Orcas were targeted in commercial whaling for the middle part of the twentieth century once stocks of larger species had been depleted. Commercial hunting of orcas came to an abrupt halt in 1981 with the introduction of the moratorium on all whaling. (Although from a taxonomic point of view an orca is a dolphin rather than a whale, it is sufficiently large to come under the purview of the International Whaling Commission.)

Vessel Traffic

With the increase of vessel traffic comes the increase of noise and disturbance in the killer whales' habitat. Long-term effects of vessel disturbance on killer whales are unknown, but short-term effects have been documented

Whales rely heavily on sound to communicate and navigate. Underwater noise pollution from boats and other human activities has the potential to interfere with the whales' ability to communicate with one another while foraging, or mask echolocation signals the whales use to locate prey. In addition to all the noise pollution, killer whales also face the danger of ship strikes and being hit by boat propellers.

Decreasing Food Supplies

In recent years, the population of British Columbia and Washington's salmon stocks has been declining dramatically. Declines could be due to degradation of spawning habitat, reduced ocean survival and over-fishing. Resident killer whale populations feed preferentially on these fish. In particular, chinook salmon are their favourite salmonid species. Returns of chinook to many coastal spawning streams and rivers have been poor in recent years. How this reduction in salmon availability may affect resident killer whales in the long run is difficult to say. They may have to switch their diet to another species or shift their distribution patterns to other areas where food is more plentiful. Transient killer whale prey is very plentiful in B.C. and Washington, however, in areas like Alaska and the Aleutian Islands, populations of seals and sea lions have declined sharply. This may be affecting transient killer whales in those areas.

Pollution

West Coast killer whales have recently been found to be the most contaminated marine mammals in the world. Synthetic chemicals such as PCBs have been banned in Canada and the US for years but their use is still occurring in areas around the world.

These chemicals are very long lived and can remain in our atmosphere for decades after their production. Once they get in the marine environment they bioaccumulate up the food chain. Marine mammals tend to be top predators and therefore consume large amounts of contaminated food. Whether or not these high levels are a serious threat to the health and survival of killer whales is unknown at this time. But PCBs have been known to cause weakened immune systems and to impair reproduction in harbour seals leading to an increased susceptibility to disease.