Bowhead whale

Bowhead whales eat tiny animals that float in the sea.

The whale opens its huge mouth. Long, bristly plates called baleen work like a sieve. The water flows out, and the food stays in.

Even though bowheads are giants, they eat tiny animals: krill and copepods, small shrimp-like animals that drift in the water.

Bowheads are baleen whales. Instead of teeth they have hundreds of long plates of baleen hanging from the top of the mouth, with about 300 on each side. The whale takes in a huge mouthful of water and strains out the food, like water pouring through the teeth of a comb. NOAA Fisheries estimates a bowhead needs about 100 metric tons of food a year.

Small to medium-sized crustaceans, especially krill and copepods, make up most of the diet; mysids and amphipods are also common, and at least 60 prey species have been recorded (IUCN). Bowheads have the longest baleen plates of any whale, and a single plate can be about 13 feet (4 meters) long (North Slope Borough).

Feeding depth changes with the seasons: in winter bowheads seem to feed mainly near the bottom, while in summer and autumn they feed mostly in mid-water and near the surface where copepods are concentrated. NOAA estimates each whale needs about 100 metric tons of prey a year.

Bowhead whales make lots of different sounds.

They call to each other under the water. Their calls help them find their way under the ice.

Bowhead whales are very noisy. They make many different calls, and sound helps them stay in touch, find food and avoid danger.

NOAA Fisheries says bowheads use the echoes of some of their calls to help find food and to find their way through the ice as they migrate. Low sounds travel a long way under water, so they may let bowheads talk across great distances.

Bowheads are highly vocal, with a large repertoire of calls. NOAA notes that echoes of some calls appear to help them find food and navigate through ice during migration, and that, judging from anatomy and the calls of related whales, they probably hear best at low frequencies, which can carry long distances.

Most of the Western Arctic population winters in the Bering Sea and moves north and east into the Beaufort Sea as the ice opens in spring. Studies near seismic surveys for oil and gas have recorded changes in diving and calling, which is one reason noise is watched closely as the Arctic opens up.

Long ago, people hunted many bowhead whales.

Now they are protected, and their numbers have grown again. Today there are many thousands of bowhead whales.

For hundreds of years, whalers hunted bowheads for their oil and baleen. By the 1920s there were fewer than 3,000 left in the whole world. Then commercial whaling of bowheads was banned.

Since then many bowheads have come back. The IUCN now lists them as Least Concern, with more than 25,000 whales. But two small groups, near Svalbard and in the Sea of Okhotsk, are still tiny, and melting sea ice brings new worries such as more ships and noise.

Commercial whaling from the 1500s onward depleted bowheads everywhere; NOAA says global numbers fell below 3,000 by the 1920s. Commercial hunting has been prohibited since the 1930s. The IUCN's 2018 global assessment lists the species as Least Concern and increasing, with over 25,000 animals; the Western Arctic stock grew about 3.7 percent a year and NOAA's current estimate is about 15,229 (2019 surveys).

The Okhotsk Sea and East Greenland-Svalbard-Barents Sea subpopulations remain small fractions of their former size and are assessed separately as Endangered. Limited hunting by Indigenous communities is managed under International Whaling Commission rules and has not prevented recovery. Watch-points include entanglement in fishing gear, ship strikes, noise, oil and gas development, and long-term loss of sea ice.