At representatives of some species of a kangaroo the weight of newborn cubs is only 500 — 750 milligrams, that is is nearly 30,000 times less, than at mother.
As kangaroo cubs are bornAccording to specialists zoologists, at a kangaroo female whose height about one and a half meters, the kid of 2 centimeters is born. Practically right after the birth the microscopic kengurenok has to cover the considerable distance to a maternal bag. Scientists long could not solve as the newborn manages to find the road there, the female, at first sight, helps nothing to the kid. According to observations of zoologists, become kangaroo mother, quietly keeps within on a back, only glancing at the newborn cub. And mother has right to rest - even before childbirth she did considerable work: she carefully licked the surface of the stomach. However movements of language were quite thought over - mother diligently prepared quite narrow strip which will become the convenient path conducting directly to a bag.
However, according to other sources, at some species of a kangaroo mother quite often helps the kid, softly pushing him to a bag.
This path which is diligently made by mother is almost sterile and in itself prompts to the kid a right way - sliding on wet wool, a cub, trying to creep, can not be afraid to turn aside. As soon as it curtails from the correct route, it will appear on dry wool, the instinct will prompt to it at once to return back - on "a slippery path" on which it will get straight to mother's bag.
Kenguryata are born blind and almost naked, their length this moment is only 2 centimeters, and weight - 1 gram. It should be noted that it is indicators at a kangaroo of large types. At the least representatives of this family of marsupials, the so-called wood kangaroos living on trees, cubs are born smaller and easy.
Development is kengurit in a maternal bag
Having been born underdeveloped and not having ability independently to suck, the kenguryat right after penetration into mother's bag literally grow to a nipple. The end of a nipple as a result quite strongly inflates, filling all mouth of the kid. Thanks to reductions of a special muscle which squeezes lacteal gland of mother, milk begins to be injected directly into a mouth a kengurenka.
In a bag the kid should spend about eight months. According to the zoologists watching these animals, quite often the kid it ceases to be fed with milk and leaves the shelter only after the birth of a new cub.
Not so long ago it became known of tragic incident in the Kaliningrad zoo when the pack of stray dogs, having jumped at night through a protection, tore to pieces family of a kangaroo. As a result states of emergency died 5 adults of animals. Only a time later experts of the menagerie with surprise and joy found out that in a bag of one of females there is a living kid. Nobody assumed that in family of the died kangaroos there was a replenishment - a cub which age was about 3 months, was reliably hidden in a maternal bag and escaped only thanks to it.