Saturday, November 24, 2012

Long Beaked Echidna

Long Beaked Echidna | Endemic to New Guinea, long-beaked echidnas are widespread and found in both Papua New Guinea in the west and Papua on the Indonesian side. They are also known from the island of Salawati off New Guinea’s western tip, and may possibly occur on the islands of Supiori and Waigeo, although their presence here has yet to be confirmed.

Recently classified as three separate species, long-beaked echidnas belong to an ancient clade of egg-laying mammals that includes the platypus of Australia. They are easily distinguished from short-beaked echidnas by their long snouts, which account for two-thirds of the length of the head. Despite laws designed to protect these species, they are in decline in areas accessible to humans. Echidnas have lost much of their forest habitat to logging, mining and farming, and are regarded as highly prized game animals by local people, who hunt them with specially trained dogs. One species, Attenborough's long-beaked echidna, is thought to have an extremely restricted range and may be at high risk of extinction.

Long-beaked echidnas are monotremes, a group that also includes the short-beaked echidna and duck-billed platypus. Fossil evidence indicates that this group of mammals has changed very little during the last 100 million years. However, the fossils do not provide any evidence of the origins of the group and their ancestral relationships, nor to how they relate to marsupials and placental mammals. Fossil monotremes from the Pleistocene Epoch (which began 1.8 million years ago) are very similar to the living species.

The most distinguishing feature of long-beaked echidnas is their long snouts, which curve downwards and account for two-thirds of the length of the head. They have no teeth; instead their tongues are covered in spikes (teeth-like projections), which are very effective in hooking prey and drawing it into the mouth. They have compact, muscular bodies, with strong limbs and claws for digging. Their back and sides are covered with spines, which vary in colour from white through to dark grey or black. The body is also covered in brownish-black hairs, which sometimes hide the spines. Males are larger than females and have spurs on the inside of the hind limbs, near the foot.

Little is known of the ecology of long-beaked echidnas. They are thought to be largely nocturnal, spending the day resting in shallow burrows or hollow logs, and foraging amongst the forest litter at night for food. The diet consists almost exclusively of earthworms, although individuals may occasionally eat termites, insect larvae and ants. Echidnas lead solitary lives, coming together only to breed. This is thought to be seasonal, with the female laying 4-6 eggs into her pouch each July. Hatching occurs ten days later, and the young echidnas remain in the pouch for a further 6-7 weeks, or until the spines develop. All echidnas have the ability to erect their spines when they feel threatened. If the ground is soft, the animal will burrow into it to protect its belly. On hard ground it will curl up into a spiky ball like a hedgehog.

No comments:

Post a Comment