Mammals




Monotreme
"Monotreme" means "one opening" and refers to the single rear opening, that these animals have for getting rid of wastes, laying eggs, and mating. The lower intestine, excretory system and reproductive system all end at this opening, called the cloaca. This feature is common in reptiles and birds but extremely rare among mammals. The most well-known and special feature of the monotremes, and the one that seems most reptilian, is that the females lay eggs rather than giving live birth. Monotremes are the only living, egg-laying mammals. Other characteristics that platypus and echidnas have in common are similar skeletons and highly modified snouts equipped with nerves whose endings are sensitive to pressure and to natural electricity. Monotremes have fur, but not whiskers, while the echidnas, in addition to fur, have sharp, defensive spines, which are modified hairs, scattered over their backs and sides.Monotremes walk in a reptilian manner, like alligators and crocodiles. Like the arms of someone in the middle of doing a pushup, the upper bones of monotreme forelimbs and hindlimbs go straight out from the body, horizontal to the ground, and the lower limb bones go straight down. Other lines of mammal evolution have abandoned this clumsy sort of movement and now carry their entire legs vertically beneath their bodies.

Special Exhibition- Duck Billed Platypus
Duck-Billed Platypuses are semi-aquatic mammals. They have a body length between 40 and 60 cms, a tail length between 8.5 and 15 cms, a bill length between 5.2 and 5.8 cms and they weigh between 0.8 and 2.5 Kgs . Males are larger than females and there are size variations depending on their location and the season. They have short, thick fur which is coloured dark brown on their back, but lighter on their underside. They have short limbs with webbed front feet and partially webbed hind feet. Males have a horny spur that they can emit venom from while fighting, which is strong enough to kill small animals and cause intense pain to a human. Their bill is flexible and it is covered in electroreceptors and mechanoreceptors that respond to electrical and tactile stimuli. Their tail is broad and flat and is used to aid swimming and to store fat reserves, an adaptation it shares with the tasmanian devil. They rest in their burrows during the day and they are mainly active at night. They are excellent swimmers and they spend most of their time in the water. They can close their nostrils, eyes and ears to prevent water from entering them when they dive below the surface. Platypuses are known to emit a low growl if they are disturbed and several other vocalizations have been herd being emitted from captive animals.

Marsupials
All marsupials share reproductive traits that distinguish them from other mammals. For example, the uterus, the organ in which the female carries her young, is divided into left and right compartments. The female has two vaginas, or openings, one leading to each compartment. The male penis usually is two-pronged, which enables the male to place one prong in each of the female’s vaginas during mating. One of the more significant reproductive traits is the lack of a true placenta in pregnant marsupials. The placenta is an organ that develops in most other mammals, called placentals, to provide nutrients and remove wastes from the developing embryo. Instead of a fully developed placenta, the pregnant marsupial forms a type of yolk sac in her uterus. The embryo absorbs nutrients from this yolk sac for four to five weeks, after which it emerges from the birth canal in an extremely undeveloped state.

Special Exhibition- Koala
Koalas are relatively small to medium size marsupials. Several theories relating to the adaptive size of koalas have been proposed by researchers. They suggest that because koalas rely on fermentation of eucalyptus leaves to obtain energy, their body size must remain relatively small in order to increase the relative volume of fermentation chambers with respect to the rest of their body. This ensures that koalas are able to meet their energy requirements. Also, because koalas are arboreal, there must be a consideration for the energetic costs required to shift a body against the forces of gravity. If koalas grew too large, it would increase the necessary metabolism and energy required for climbing. Under the influence of these considerations, koalas have reached a relatively optimal size for a herbivorous, arboreal mammal. The size of a mature koalas is slightly variable, and males are typically larger than females. Full grown males range between 20 & 30 pounds while females generally range between 15 & 22 pounds. Males usually grow to be between 29 & 33 inches, and females grow to be between about 26 & 29 inches (Sea World). Koalas have stocky, pear-shaped bodies. Their wide base is advantageous for balance and wedging themselves into the forks of trees. Koalas also have a reduced tail and relatively long limbs which benefit in sitting and climbing.

Dog
Domestic dogs come in a bewildering variety of shapes and sizes. They have been selectively bred for millennia for various behaviors, sensory capabilities, and physical attributes, including dogs bred for herding livestock, different kinds of hunting, catching rats , guarding, helping fishermen with nets, pulling loads, guarding carriages and horsemen, and as companion dogs. Some kinds were even bred simply as lap warmers. Their basic morphology though, no matter how modified, is that of their wild ancestors, gray wolves. Like many other predatory mammals, the dog has powerful muscles, fused wrist bones, a cardiovascular system that supports both sprinting and endurance, and teeth for catching and tearing. Compared to the bone structure of the human foot, dogs technically walk on their toes.

Polar Bear
Polar bears are the largest land carnivore. Male polar bears (boars) grow two to three times the size of female polar bears (sows). Boars weigh about 350 to more than 650 kg and are about 2.5 to 3 m long. Sows weigh about 150 to 250 kg and are about 2 to 2.5 m long. Pregnant females can weigh as much as 500 kg. The largest polar bear ever recorded was a male weighing 1,002 kg and measuring 3.7 m long . Compared to other bears, polar bears have elongated bodies and long slender necks.The coat can vary from pure white to creamy yellow to light brown depending upon season and angle of light. The hind limbs are longer than the forelimbs. This makes the large, muscular hind end stand higher than the shoulders.Polar bear legs are large and stocky. Feet are five-toed paws. Polar bears have large paws compared to body size, reaching 30 cm in diameter. The large paws of a polar bear act like snowshoes, spreading out the bear's weight as it moves over ice and snow.The forepaws are round, and the hind paws are elongated.Each toe has a thick, curved, nonretractable claw. The claws are used for grasping prey and for traction when running or climbing on ice. The sole of a polar bear's foot has thick, black pads covered with small, soft papillae (dermal bumps). The papillae create friction between the foot and ice to prevent slippage. Long hairs growing between pads and toes also help prevent slippage. A polar bear's head is oblong and relatively small compared to body size. The muzzle is elongated with a "Roman-nosed" (slightly arched) snout.The nose is broad and black. Polar bears have 42 teeth, which they use for catching food and for aggressive behavior. Polar bears use their incisors to shear off pieces of blubber and flesh. Canine teeth grasp prey and tear tough hides. Jagged premolars and molars tear and chew. Polar bears swallow most food in large chunks rather than chewing.A polar bear's eyes are dark brown, set relatively close together, and look forward. The ears are small and rounded, and lay flat when under water. The tail is small, about 7 to 12 cm long. Polar bears are completely furred except for the nose and footpads, which are black. A polar bear's coat is about 2.5 to 5 cmthick. A dense, woolly, insulating layer of underhair is covered by a relatively thin layer of stiff, shiny, clear guard hairs. Polar bear fur is oily and water repellent. The hairs don't mat when wet, allowing the polar bears to easily shake free of water and any ice that may form after swimming. Ice forms when the wet fur is exposed to air temperatures at or below freezing. The hairs reflect light, giving a polar bear its white coloration. Oxidation from the sun, or staining, can make the hairs look yellow or brown. Polar bears completely molt (shed and replace their fur) annually, in May or June. The molt can last several weeks. A polar bear's skin is black. A polar bear's coat is about 2.5 to 5 cm thick. A dense, wooly, insulating layer of underhair is covered by a relatively thin layer of stiff, shiny, clear guard hairs.

Panda
Pandas are about the size of the American black bear. An adult panda is typically 1.5 meters long and weighs about 75 to 135 kilograms . Males are 10% to 20% heavier than females. Pandas live between 18 to 25 years in the wild. Pandas have large molars and large jaw muscles extending from their jaw to the top of their head that crush the fibrous plant material and tough stalks of their main food, bamboo. Pandas are most active at twilight and night. Their pupils have vertical slits, like snakes and many nocturnal animals, which allow them to see better at night. Flexible forepaws and an enlarged wrist bone that works as an opposable thumb are useful for handling bamboo. Like humans, pandas walk with both their heel and toes make in contact with the ground. Hairs on the soles of their feet give them traction and reduce heat loss on ice and snow. Pandas can climb trees. Usually, however, only cubs or females in heat climb trees. The panda's coat has two layers: a coarse outer layer and a dense, wooly under layer. Their fur is slightly oily which prevents water penetration in the cool, damp climate where the pandas live.

Homo sapiens
Homo sapiens is identified, for purposes of classification, as an animal with a backbone that suckles its young; that gestates its young with the aid of a placenta; that is equipped with five-digited extremities, a collarbone, and a single pair of mammary glands on the chest; and that has eyes at the front of the head, stereoscopic vision, and a proportionately large brain. The species belongs to the family Hominidae. The details of skeletal structure distinguishing Homo sapiens from the nearest primate relatives—the gorilla, chimpanzee, and orang-utan—stem largely from a very early adaptation to a completely erect posture and a two-footed striding walk. The uniquely S-shaped spinal column places the centre of gravity of the human body directly over the area of support provided by the feet, thus giving stability and balance in the upright position. Other mechanical modifications for bipedalism include a broad pelvis, a locking knee joint, an elongated heel bone, and a lengthened and aligned big toe. Although varying degrees of bipedalism are seen in other anthropoids, all have straight or bowed spines, bent knees, and grasping feet, and all use the hands to bear part of the body weight when moving about.

Killer Whale
The orca or killer whale is a toothed whale and is a member of the Dolphin family (it is the largest dolphin). There are 3 distinct species of these warm blooded, air breathing mammals: Resident Killer Whales, Transient Killer whales, and Off-shore Killer Whales. The main factors which set each species apart are - social behavior, physical appearance, preferred food, and vocal dialects. At this stage, there is little known of the Off-Shore species of Killer Whales as they are seldom seen in protected coastal waters. Although the travelling ranges of Residents Killer Whales, Transients Killer Whales, and Off-shores Killer Whales overlap, they have never been seen to mix.One of the best locations for orca whale watching is off Vancouver Island in British Columbia, Canada. Here you can find a story about a orca whale watching tour off northern Vancouver Island, British Columbia. Check out this website for interesting pictures from British Columbia. Killer Whales are easily recognized due to their striking black and white coloration, and a sleek, streamlined, fusiform (tapered at both ends) body shape. The rounded and paddle-like forelimbs are pectoral flippers which are used mainly to steer and, with the help of the flukes, to stop. The dorsal fin acts as a keel and probably helps stabilize a killer whale. The dorsal fins of male killer whales are the tallest of any cetacean in the world, growing up to 1.8 m (6 ft.). Female dorsal fins are smaller at about 0.9 to 1.2 m (3-4 ft.) and may be slightly curved back. Male killer whales, or bulls, begin maturing at 12 to 14 years of age and over the next few years, grow very quickly and attain physical maturity at about 20 years. Most males probably reach a length of 8 to 9 metres. Females, or cows, average about 7 metres in length and reach reproductive maturity at about 14 to 15 years. The gestation period is 16 to 17 months. A single calf is usually born (although twins have been recorded). 200 kilograms. Newborn killer whales nurse for at least one year. The mortality rate of calves is quite high - over 40% of resident calves die in their first six months.

Vampire Bat
Vampire Bats are small flying mammals. They give birth to live young and nourish them with milk. They are nocturnal; they are most active at night and sleep during the day hanging upside-down. Vampire Bats live in Central and South America. Vampire Bats are microchiropterans, bats who use echolocation. Bats' wings are long fingers covered by thin skin, and they have furry bodies. These tailless mammals have weak legs and don't walk very well. Vampire Bats have a wingspan of only 8 inches (20 cm). The body is the size of a person's thumb. Vampire Bats can see, but use echolocation as their primary sense in order to find insects and small animals to eat. While flying, these bats send out high-pitched sounds that bounce off other objects. The bat listens for the bounced sound, and can determine where objects are located. People cannot hear these high-pitched sounds. The vampire bat is the only bat (and the only mammal) that eats blood, preying on cattle, horses, large birds and pigs. Vampire bats don't suck animals' blood, they make a small hole with their two very sharp incisor teeth and lap up the blood, which doesn't clot (thicken) because of anti-coagulants (anti-thickeners) in the bat's saliva.

Chimpanzee
Chimoanzee belong to the order Primates, which includes monkeys, apes, and humans. Chimpanzees are assigned to the family Pongidae, which includes all of the other apes: gorillas, orang-utans, and gibbons. Compared with monkeys, apes are larger, have no tail, and have longer arms and a broader chest. When apes stand upright, their long arms reach below their knees. They also have a great deal of upper body strength, needed for a life spent mostly in the forest canopy.