Sperm Whale

True Wild Life | Sperm Whale | The sperm whale is one of the world's water giants and is found in ocean waters worldwide. Although historically known as the common cachalot, the sperm whale gets it's name from the waxy-liquid substance found in it's head, that is used in candles, soap and cosmetics by humans. The sperm whale was once found in large groups, known as pods, around the world but extensive whaling of the sperm whale has led to it being classified as a vulnerable species today. The sperm whale is most commonly found in the deep ocean, where there is an abundance of food and along continental shelves.

An adult sperm whale can grow to nearly 70ft long, making the sperm whale the largest toothed animal on the planet (although about a third of the length of the sperm whale is made up of it's head alone). Sperm whales have around 50 large teeth in total, which are cone-shaped and weigh about 1kg each. Sperm whales are not only one of the world's biggest animals but are also one of the deepest diving animals in the ocean (along with elephant seals and bottlenose dolphins), and commonly dive to depths of nearly 500 metres for up to half an hour at a time. It is believed however, that sperm whales are able to dive much deeper reaching depths of around 3 km for periods of 90 minutes or more.

The sperm whale is one of the ocean's largest and most dominant predators, feeding primarily on medium sized squid. The sperm whale is also known to hunt larger squid species including the colossal and giant squids, and also octopus and large fish. The sheer size of the adult sperm whale means that it has no real natural predators in the ocean, besides being over-hunted by humans. The smaller sperm whale calves however have been known to be taken by killer whales and occasionally large sharks.

After a gestation period that lasts anywhere from a year to a year and a half, the female sperm whale gives birth to a single sperm whale calf into the surrounding water. Calves are thought to suckle (feed on their mother's milk) for up a few years before they begin hunting for themselves. Female sperm whales are able to breed when they are around 10 years old and can live to be beyond the age of 70.

Today, due to centuries of hunting, the sperm whale population is thought to be under threat in the wild. Although the sperm whale population is said to be stronger than that of other whale species, sperm whales are also now under threat from other factors including noise and chemical pollution in the water.

Minke Whale

True Wild Life | Minke Whale | There are two recognised subspecies of minke whale, the common minke whale and the larger Antarctic minke whale, both however are classified as baleen whales meaning that minke whales filter food from the water rather than biting it. The common minke whale (dwarf minke whale) is generally found in the North Atlantic Ocean and also parts of the North Pacific Ocean. The common minke whale (dwarf minke whale) is the smaller of the two minke whale subspecies with adult common minke whales reaching about 5 m in length.

The Antarctic minke whale is found inhabiting the frozen Antarctic waters but the Antarctic minke has also been known to venture into the Southern Atlantic Ocean and occasionally the Southern Pacific Ocean. The Antarctic minke whale is the larger of the two minke whale subspecies, and at around double the size of the common minke whale, some adult Antarctic minke whales grow to more than 10 meters in length! Despite the clear division of the two minke whale species territories, it is not uncommon for the common minke whale to be found in the waters of the southern hemisphere although the Antarctic minke whale is rarely found too far north. The reason behind this is thought to be because the common minke whale can survive in more temperate waters, where the Antarctic minke whale prefers to inhabit the more frozen ones.

The minke whale has a carnivorous diet, as the minke whales filters to water in the oceans to extract nutrients from it. Amongst the most common minke whale meals are krill and plankton, but minke whales will often eat small fish and crabs. As the minke whale is a type of baleen whale, the minke whale does not have teeth as such. The tiny bristle like teeth in the mouth of the minke whale means that the minke whale cannot really bite down on food, so the minke whale uses its teeth to filter food particles out of the water.

Minke whales tend to breed in the late winter to early spring, with minke whale breeding occurring near the surface of warmer waters. The gestation period is about 10 months and the calf is born near the surface of warm, shallow waters. The newborn minke whale calf is able to swim to the surface of the water within 10 seconds for its first breath with a little help from its mother who uses her flippers to guide the minke whale calf to the surface. Minke whales calves are usually able to swim within their first half and hour of life.