The narwhal, often referred to as the “unicorn of the sea” due to its distinctive long tusk, is a whale species that navigates the challenging Arctic waters. It has adapted to its icy environment, with a specialized diet and unique feeding methods. Its feeding habits are tied to prey availability in its cold, deep-water habitats.
Arctic Delicacies
Narwhals primarily consume a limited range of prey, which aligns with the deep-sea ecosystems they inhabit. Their diet mainly consists of Greenland halibut, a flatfish found near the seabed, and various types of cod, including Arctic cod and polar cod. In addition to fish, narwhals also feed on cephalopods like Gonatus squid and crustaceans such as shrimp.
The size of their prey varies, with Greenland halibut typically ranging from 35-55 cm in length and weighing between 200-1400 grams, while squid are much smaller, averaging around 23 grams. Narwhals feed by swimming close to their prey and using a suction method to draw food into their mouths, as they lack well-developed teeth for chewing. Their feeding intensity also changes seasonally, with significant consumption occurring during late autumn and winter.
Strategies for Foraging
Narwhals are deep divers, allowing them to access deep-dwelling prey. They routinely undertake profound dives, often descending to depths exceeding 800 meters and sometimes reaching over 1,500 meters, spending considerable time in these dark, cold environments. These deep dives are particularly common in winter when narwhals inhabit offshore waters covered by dense pack ice. Their ability to withstand high pressures and manage oxygen during these prolonged submersions is a testament to their specialized physiology.
The narwhal’s renowned tusk, which can extend up to three meters in males, plays a role in their foraging behavior. While historically debated, recent drone footage has provided insights, showing narwhals using their tusks to tap and stun small fish, such as Arctic cod, making them easier to capture. This suggests the tusk can act as a tool for manipulating prey before consumption. Beyond a hunting aid, the tusk is also considered a sensory organ, capable of detecting changes in water temperature and salinity, which could assist in locating food sources or navigating their environment.
Narwhal migration patterns also influence their access to food sources. They exhibit predictable seasonal movements, transitioning from ice-free summering grounds to offshore wintering areas under thick pack ice. This migratory behavior ensures access to prey, especially rich Greenland halibut populations in areas like Baffin Bay.