THE WILD MAMMALS
(Dr. Girish Chandra)
MONOTREMES (THE EGG LAYING MAMMALS)
The ECHIDNA (Tachyglossus and Zaglossus)
Echidna is sometimes referred to as a Spiny Anteater since it has sharp spines on their backs. The Echidna is found all over Australia in different temperatures and habitats. Echidnas live in forests, woodlands, deserts and mountains. They are generally crepuscular and nocturnal, when they dig termite hills and feed on termites and other insects.
The PLATYPUS (Ornithorynchus anatinus)
The duck billed platypus which is the only mammal in the world to have a beak, fur and webbed feet, is found in lakes, creeks, rivers and streams along the eastern side of Australia, from Cooktown in north Queensland to Hobart. Body is exceptionally well stream-lined for aquatic life. The fur is waterproof, with an outer layer of long flat-bladed guard hairs and an inner layer of fine hairs, which trap air and maintain body temperature. They feed on crustaceans and molluscs which they crush with epidermal horny plates inside their oral cavity.
MARSUPIALS (THE POUCHED MAMMALS)
Marsupials include kangaroos, koalas, wallabies, wombats, bandicoots, and opossums. The red kangaroo (Macropus rufus) is the largest of them that can reach a height of six feet when standing on hind legs and weigh as much as 80 kg. The smallest living marsupials include the pilbara (Ningaui timealeyi) that weighs less than 3.0 grams and Planigale ingrami that measures 4.7 inches in length and weighs 4 grams.
The Blue Whale (Balaenoptera musculus) is a marine mammal. It measures up to 33 metres (110 ft) in length and weighs about 180 tonnes. It is believed to be the largest animal to have ever lived. The Blue Whale’s body is long and slender and can be various shades of bluish-gray with ventral side pale yellow. The dorsal fin is very small. The head is flat and has a prominent ridge running from the blowhole to the top of the upper lip. The front part of the mouth is thick with baleen plates, which are around 300 in number, each around one metre long and hang from the upper jaw. Between 60 and 90 grooves called ventral pleats run along the throat parallel to the body. These plates assist in evacuating water from the mouth after lunge feeding. Blue whales feed almost exclusively on krill which are crustaceans.
The sperm whale (Physeter catodon) is named owing to a waxy spermaceti oil that this whale produces in the spermaceti organ located in its head. The sperm whale is a toothed whale that has a huge brain that weighs about 9 kg, which is the largest brain of any animal. The sperm whale has a single 20 inches long blowhole. Sperm whales are the largest toothed whales. Adult males grow to be about 50-60 feet long, weighing about 40-50 tons. Females are smaller, about 33-40 feet long, weighing about 14-18 tons. The four-chambered heart of the average sperm whale weighs about 126 kg.
Manatees (Trichechus species) are large, fully-aquatic marine mammals sometimes known as sea cows that are classified in the order Sirenia. The name comes from the Spanish manatí, meaning "breast" indicating prominent thoracic mammary glands. They are mainly herbivores, spending most of their time grazing in shallow waters and at depths of 1-2 m. Manatees can be found in shallow, slow-moving rivers, estuaries, saltwater bays, canals and coastal areas.
The Dugong (Dugong dugon) is the smallest member of the order of Sirenia. It derives its name from the Malay term, duyung means "lady of the sea" or "mermaid". Dugongs are found discontinuously in coastal waters of east Africa from the Red Sea to northernmost South, northeastern Indian, along the Malay peninsula, around the northern coast of Australia to New Guinea and many islands of the South Pacific. Dugongs are aquatic herbivores and feed on the sea grasses and are reported to occasionally eat algae.
Dolphins (Delphinus delphi and other species) are marine mammals that are closely related to whales and porpoises. There are about 40 species of dolphin in 17 genera. They vary in size from 1.2 metres and 40 kilograms to 9.5 m. They are found worldwide, mostly in the shallower seas of the continental shelves, and are carnivores, mostly eating fish and squid. The family Delphinidae is the largest in the Cetacea, and relatively recent: dolphins evolved about ten million years ago, during the Miocene. Dolphins are considered to be amongst the most intelligent of animals and their often friendly appearance and seemingly playful attitude have made them popular in human culture.