For a long time, even zoologists could not answer the question of how the kangaroos give birth. Despite the widespread distribution of these marsupials in Australia, Tasmania and New Guinea and their close proximity to humans, they managed to retain many secrets. Only at the present stage of the development of science did scientists learn how the kangaroo genus takes place .
Kangaroos do not have a certain season when mating should take place. But the reproductive processes in representatives of all kinds of kangaroo are very active.
In the nuptial period, the real fights between males can unfold for the attention of females. A very important role in these duels is played out by the tail, which actually performs the function of the fifth leg. The winner is entitled to mating. Despite the developed sense of competition for the female, the maternal instincts are completely absent in the males. After the love games end, the male disappears. About whether the offspring will survive, the female should take care.
Pregnancy and childbirth kangaroo
The period of pregnancy in kangaroos is very short. Depending on the species, the offspring appears 30-40 days after mating. In order for labor to pass safely, the female must find a secluded place. Her position during delivery is sedentary, while the animal's tail is between the legs. It's on him that a newborn baby kangaroo falls.
Babies are born very small and translucent. In fact, this is not yet fully formed embryo. The maximum size of the body in the youngest of the largest species of kangaroos is 2-3 centimeters, and the weight is 25 grams. They have well developed only those organs that help them get into the bag to the mother. These are long, rather strong forelegs, mouth and nose.
After the childbirth is over, the kangaroo licking a path out of the wool, along which the baby must reach the bag. But you have to crawl in there yourself. This is facilitated by the location of the fur on the belly of the mother, as well as well-developed sense organs. The way to the bag the kid makes tightly clinging to the front legs for the fur on the body of the female.
The first months of life
Getting into the bag, the baby is sucked to one of the nipples of the mammary glands, which are located there. Since he is born without wool, the first few months are not able to independently adjust the temperature of his body. Therefore, within two months he never leaves his mother's bag.
This body itself has a rather interesting structure. Inside the bag is smooth, but its edges are protected by thick fur. This allows you to protect offspring from bad weather. In addition, the female kangaroo is able to control the muscles of the bag. She decides when to release a cub from her. The bag closes tight enough. For example, during swimming it does not get water.
At different stages of its development the cub eats milk, which differs in composition. The female has four nipples, and her body is capable of producing two completely different types of milk. The one that the baby drinks immediately after the kangaroo has been born has antibacterial properties. This is very important, because the immunity of a newborn is not fully formed yet.
"The large family
In 1-2 months after the birth of the first toddler the female is again ready for mating. When the second baby is born, the first one still lives in the bag. Thus, simultaneously the female kangaroo takes care of two different-aged children. The fabric of the bag is very elastic, and they are able to withstand the weight of the offspring after they begin to grow up.
At the time when the second baby appears, his older brother begins to eat milk from the second nipple, which, as already mentioned, is different in composition.
In some species of kangaroos, for example, kvokka, nature provides for the conception of two embryos at once. But first one kid develops, and only after reaching one month begins the development of the second. If the first fetus perishes, the growth of the second begins immediately. Thus, the species we are considering does not need to spend time on additional pairing.
The birth of twins or triplets happens in other, larger species of kangaroos. Photos made by scientists prove the existence of such "large families".
Typically, the baby spends in the mother's bag for about seven months. Becoming old enough, he begins to get out of it for a short time and try vegetable food. However, at the first sign of danger, he again seeks shelter in his mother's bag. Only after the baby has finally got stronger, he begins an independent life.
Care for the offspring
The functions of the female do not end with giving life to the offspring and feeding it. It ensures their safety, and also keeps the bag clean. Since a small kangaroo does not leave its habitat for the first months of life, all the products of their life activity also remain in it. Therefore, the female opens it and simply lick the cubs until they grow up.
She also removes the bag after the kangaroo people leave her forever. Often this happens when the young offspring no longer fit there. It happens that the mother throws them out on their own.
As you know, the offspring of different mothers differ in smell, so that the female recognizes her children. It is generally accepted that kangaroos do not have a propensity for adoption. Nature stipulates that there are two cubs in the bag, so for others there is no place. However, cases were recorded whereby offspring, with the permission of the female, fed and slept in her bag. Most often this happens when the older calf dies. Thus, the second nipple remains free, but milk continues to be produced.
Scientists also recorded cases when females changed their babies. The reason for their behavior is unknown.
Data on the fact that kangaroos are "adopted" by the cubs of other animals, scientists do not.