Blue whales typically breed during the winter or early spring after they have undergone a journey of several thousand miles, leaving the cold waters of the northern and southern hemispheres in favor of the warmer waters near the equator. The male and female engage in a complicated courtship ritual, rolling around each other and diving to the depths before engaging in sexual intercourse as they return to the surface.
Blue whales reach sexual maturity between the ages of 5 and 10. As with other mammals, blue whales reproduce through sexual meiosis. The male and the female each produce haploid gametes, or reproduction cells. The female gamete is the egg, and the male gamete is sperm. The male deposits his sperm inside the female with his penis, which is the largest of its kind found on Earth. If fertilization is successful, a fetus begins to develop inside the mother's uterus, and after an 11- to 12-month pregnancy, the baby blue whale calf is born near the surface of the water. It emerges tail-first and weighs around 6,000 pounds at birth. The calf promptly swims to the surface to take its first breath, aided by its mother if necessary. The calf typically stays with its mother for a year or longer before striking out on its own.Learn More
Hippopotamuses are large land animals characterized by their nearly hairless skin, wide snouts, and brown or grayish-purple skin. Hippopotamuses are the third-largest land mammals on Earth, weighing an average of 7,900 pounds and reaching approximate lengths of 15 feet.Full Answer >
Penguins are not mammals, even though they are warm-blooded animals. Penguins are one of only a few species of flightless birds left in the world. Many people mistakenly believe penguins have fur instead of feathers because of the extremely tight packing of the feathers on their bodies.Full Answer >
A young whale is called a calf. The female whale is known as a cow, while the male is known as a bull. The gestation period of a whale can last from 9 to 18 months. The calf suckles from 6 months to 2 years before becoming an adult.Full Answer >
The bottlenose dolphin's diet consists primarily of fish and marine invertebrates. Other dolphins eat a variety of foods depending on their species, available food and the methods they have learned for hunting.Full Answer >