Where Do Whales Live?
Some cetacean species’ distribution is limited while others are found worldwide. Large species like blue, humpback, and fin whales are found globally, although they have their own groups and, in some cases, subspecies that have their own range.
Some whales, like belugas, narwhals, and bowheads, typically spend their whole lives in arctic regions. While these animals still do migrate, they normally remain in arctic waters. Some strays have been observed outside of the arctic. For example, three belugas were seen in Rhode Island waters in 2015. A lone bowhead was seen off Cape Cod in 2012 and 2014.
There are few endemic cetaceans in warmer water, with a notable example being the near extinct vaquita in Mexico, along with some species of dolphins.
In the U.S. certain endangered species, such as the North Atlantic right whale, receive extra protection via designation of foraging and calving areas as critical habitat. As defined by the Endangered Species Act, this is ‘specific geographic areas that contain features essential to the conservation of an endangered or threatened species and that may require special management and protection’. This protection dictates that ‘all Federal agencies must ensure that any actions they authorize, fund, or carry out are not likely to jeopardize the continued existence of a listed species, or destroy or adversely modify its designated critical habitat’.
Baleen whale species migrate annually, with many following a predictable pattern. In particular, both humpback and gray whales have notably long migrations.
Both species have migrations that total over 10,000 miles round trip, with the longest recorded migration being a 13,988 mile journey by a gray whale from Mexico to Russia and back. These animals have not only the longest migrations for whales—it is the longest migration for any mammal.
Animals migrate for a variety of reasons, including following food sources and giving birth. Along the Massachusetts coast, several species, including humpbacks, arrive in the spring to feed on large populations of small fish and zooplankton throughout the summer. These animals had spent their winter months in the Caribbean where the water is warm, but the ecosystem doesn’t provide much, if anything, to eat.
Conversely, many whale species dedicate their winter months to breeding and calving. In these months, whales migrate to warm tropical climates to give birth, as the calves have only a thin layer of blubber. Being born in warmer water puts less stress on their bodies.
Because whales have the ability to metabolize energy from the oil in their bone marrow and from blubber, certain species of whales can go months without eating while living off these energy reserves. They build up their reserves during the many hours of daily feeding during the spring and summer. In fact, they may eat as much as 4% of their body weight each day during the summer.
Some whales exhibit different migration patterns based on sex and/or age. For example, for right whales, it’s mainly the pregnant females who migrate. However, for humpback whales, both sexes are seen migrating. Calves will stay with the mother to nurse until they can hunt on their own, at which point they follow their normal migration cycle (around one year for baleen whales to be weaned).
On the other hand, most toothed whales are not thought to have set migration patterns. In sperm whales, the females and calves will stay in the breeding grounds close to the equator their whole lives. Male sperm whales have been found to wander the colder areas of the oceans alone, except for when breeding.
Coastal vs. Deep Water
Cetaceans live at a variety of depths depending on the species. For example, beaked whales are deep divers that are typically seen far from shore. North Atlantic right whales and gray whales can be seen without the use of binoculars if their prey items bring them in close to shore.
Others, like orcas, either stay in one general area if they are residents of that region (for example, the Salish Sea) or travel to different ocean habitats if they are transient pods.