A B1 killer whale is a type of killer whale that is smaller than their big type A conspecifics. They have very large eye patches and typically show a beautiful pattern of grey on their back called a “dorsal cape.” They can appear yellowish at times because of the diatoms (cold water algae) that grow on their skin. B1 killer whales are slightly larger than type B2, ranging between 6 and 8 meters (20-26 ft) meters. They typically feed on seals, travel in small groups, and stick to the ice pack, where they can hunt easily. B2 killer whales tend to travel in larger groups and feed on a larger range of prey, such as penguins, fish, and occasionally Weddell seals. Both subtypes coexist in the same environment. B1 killer whales are rarer than B2 and might face critical threats due to climate change. A recent study focusing on the Western Antarctic Peninsula reported that the population size of type B1 is smaller than type B2 in the area and that the population of B1 killer whales is declining annually by about 5%, which could be explained by climate change and the loss of sea ice.