Elephants are placental mammals, which means their young grow inside of the mother and are fed through a placenta that is attached to her body. Elephant babies are born live, not hatched from eggs.
Elephants give birth around every four years, and given their pregnancies can last around two years, that is quite a lot! Although elephants can live for 60-70 years, they typically only have about four or five babies during their lives.
Females give birth while standing. The birth itself lasts only a few minutes. A single calf is usually born head and forelegs first.
The egg of an elephant is Microlecithal and Isolecithal.
On other hand, Kangaroo are pouched mammals. They don't lay eggs, their young one is born in an immature state. Gestation period shows complete development in the abdominal pouch or marsupium.
All crocodiles lay hard-shelled eggs, which may weigh 50–160 grams (0.1–0.4 pound) each. A female lays an average of 12–48 eggs per nest, depending upon her age, size, and species.
Only two kinds of egg-laying mammals are left on the planet today—the duck-billed platypus and the echidna, or spiny anteater. These odd “monotremes” once dominated Australia, until their pouch-bearing cousins, the marsupials, invaded the land down under 71 million to 54 million years ago and swept them away.
The largest egg in the world is laid by the ostrich. The average egg of an ostrich weighs about three pounds, which for perspective is the weight of about 24 chicken eggs! Ostrich eggs are also approximately six inches long.
Ostrich eggs are the largest of all eggs, though they are actually the smallest eggs relative to the size of the adult bird — on average they are 15 cm (5.9 in) long, 13 cm (5.1 in) wide, and weigh 1.4 kilograms (3.1 lb), over 20 times the weight of a chicken's egg and only 1 to 4% the size of the female.
In fact, some elephants don't even seem to mind mice crawling on their faces and trunks. Elephant experts will tell you that elephants have no reason to be afraid of mice. In fact, they'll tell you that healthy elephants don't fear any other animals, because of their size and lack of natural predators.
Elephants are the largest land mammals in the world, so it's perhaps not surprising that they have the longest pregnancy of any living mammal: African elephants are pregnant for an average of 22 months, whilst for Asian elephants it's 18 to 22 months.
Although it seems as if Angele was trying to kick the newborn, this behavior is natural for elephants: this is how they help the little one get out of the placenta. Shortly after his birth, the little one got to his feet well and began to nurse.
Most carnivores can pause their pregnancies, including all bears and most seals, but so can many rodents, deer, armadillos, and anteaters. More than a third of the species that take a breather during gestation are from Australia, including some possums and all but three species of kangaroo and wallaby.
Elephant sex is short-lived, and females may mate with more than one bull in each estrus cycle, which can last up to 18 weeks. While elephants do not mate for life, a female may repeatedly choose to mate with the same bull, and sometimes bulls tend to get protective of these females.
There are over 500 species of shark living in waters around the world and the majority give birth to live young. The remainder are oviparous, meaning they lay eggs.
Results. In general, the eggs of insect parasites are the smallest eggs of insects. Relative to female size, the smallest insect eggs reported in the literature are the microtype eggs of Tachinidae (Hinton 1981). These eggs are usually 0.02 to 0.2mm long, very rarely as much as 0.4mm long (Hinton 1981).
The Bee Hummingbird is also the bird with the smallest nest in the world, at only 1 inch in diameter and depth. Their eggs are also the smallest bird eggs in the world, measuring a mere 12.5 x 8.5 mm, the size of a coffee bean. A Bee Hummingbird egg is only half the weight of a standard paper clip!
Ostriches are known to consume their own eggs for a variety of reasons, including as a source of nutrition and to recycle calcium and other nutrients. In the wild, ostriches often lay their eggs in communal nests, where multiple females lay their eggs in the same nest.
Do whales lay eggs? The answer is no. Because whales are marine mammals, the females carry the offspring in their wombs and have live births! However, since whales are fully aquatic mammals, how whales give births is much different than the births of terrestrial and semi-aquatic animals.
Answer and Explanation: Ostriches can lay both fertilized and unfertilized eggs, just like chickens can. It is the unfertilized eggs that people are able to eat, as they do not contain an embryo.
They react differently when external stimuli are applied while sleeping and while awake. But the bullfrog, Lithobates catesbeianus show the same reaction in both situations. This indicates that bullfrogs do not sleep. Lithobates catesbeianus is an animal that cannot sleep.
Platypus are monotremes - a tiny group of mammals able to both lay eggs and produce milk.
The Australian three-toed skink (Saiphos equalis) is doubly remarkable: Not only can it both lay eggs and bear live young, but it can do both within a single litter of offspring.