Narwhals are medium-sized whales, and are around the same size as beluga whales. Total length in both sexes, excluding the tusk of the male, can range from 3.95 to 5.5 m (13 to 18 ft). Males, at an average length of 4.1 m (13.5 ft), are slightly larger than females, with an average length of 3.5 m (11.5 ft). Typical adult body weight ranges from 800 to 1,600 kg (1,760 to 3,530 lb).Male narwhals attain sexual maturity at 11 to 13 years of age, when they are about 3.9 m (12.8 ft) long. Females become sexually mature at a younger age, between 5 and 8 years old, when they are around 3.4 m (11.2 ft) long.
The pigmentation of narwhals is a mottled pattern, with blackish-brown markings over a white background. They are darkest when born and become whiter with age; white patches develop on the navel and genital slit at sexual maturity. Old males may be almost pure white.Narwhals do not have a dorsal fin, possibly an evolutionary adaptation to swimming easily under ice. Their neck vertebrae are jointed, like those of land mammals, instead of being fused together as in most whales. Both these characteristics are shared by the beluga whale. The tail flukes of female narwhals have front edges that are swept back, and those of males have front edges that are more concave and lack a sweep-back. This is thought to be an adaptation for reducing drag caused by the tusk.
Facts
The narwhal looks like a cross between a whale and a unicorn with its long, spiraled tusk jutting from its head. Males most commonly have tusks, and some may even have two. The tusk, which can grow as long as 10 feet, is actually an enlarged tooth. Ongoing research by WWF collaborators indicates that the tusk has sensory capability, with up to 10 million nerve endings inside. The tusk may also play a role in the ways males exert dominance.
Narwhals spend their lives in the Arctic waters of Canada, Greenland, Norway and Russia. The majority of the world’s narwhals winter for up to five months under the sea ice in the Baffin Bay-Davis Strait area (between Canada and western Greenland). Cracks in the ice allow them to breathe when needed, especially after dives, which can be up to a mile and a half deep. They feed mainly on Greenland halibut, along with other fish, squid and shrimp.
Why they matter?
Whales, like the narwhal, are at the top of the food chain and have an important role in the overall health of the marine environment. Narwhals are also culturally important to indigenous communities in the Arctic. Like polar bears, the narwhal depends on sea ice for its existence and can be directly impacted by climate change.
Threats
1. Oil and Gas Development
Vessels that support oil and gas development mean increased shipping in sensitive areas. Increased shipping means more noise that can mask communications for many Arctic marine species and it increases the potential for collisions with marine mammals, especially whales. It also brings more pollution and a greater possibility of oil or fuel spills.
2. Ocean Noise
Shipping, industrial extraction, marine construction and military activities cause underwater noise pollution. Since whales depend on sound to communicate, any interference by noise pollution can negatively affect their ability to find food and mates, navigate, avoid predators and take care of their young.
3. Climate Change
Thousands of years of evolution have prepared Arctic species like the polar bear, walrus and narwhal for life on and around the sea ice. Because of climate change, that ice cover has been changing rapidly, in both extent and thickness, and shrinking far too quickly for these species to adapt. A narwhal’s entire life is connected to sea ice, both as a place to feed and a place to take refuge. Slow swimming whales rely on sea ice as a place to hide from predators like killer whales.
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