Whatever the purpose, scientists know this for certain: The Arctic region, which the narwhals call home, is warming twice as fast as the rest of the planet, and by analyzing these tusks, researchers can glean surprisingly detailed insights into how the animals are dealing with catastrophic change. Writing in March in the journal Current Biology , scientists described what they found in 10 tusks collected from animals in northwest Greenland.
They found that between and , the mercury in the tusks increased by an average of 0. This is consistent with increased mercury discovered in the bodies of other top predators in several regions across the Arctic, possibly due to air pollution blowing in from the south. This corresponds to a dramatic decline in Arctic sea ice since the year Mercury is a potent neurotoxin that bioaccumulates in species as they ingest it over a lifetime.
When an organism at the bottom of the food chain consumes mercury, it collects in its tissues. The researchers examined the measurements of male narwhals living in waters off Greenland over the course of 35 years.
They found that the largest male narwhals had disproportionately long tusks. Read More. Paid Content How Hong Kong protects its sea sanctuaries. History Magazine These 3,year-old giants watched over the cemeteries of Sardinia.
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Perhaps a narwhal uses its tusk to check the weather forecast and then steer clear of the colder and saltier water. Scientists are still puzzled by the discovery of the unique tusk anatomy. Scientists only just discovered the sensory capabilities in , so for now, we can only speculate.
Perhaps the tusk is used to locate females in heat by pinpointing hormones levels in the water. Or, perhaps, the sensory capability is a newly evolved trait that emerged after the tusk became a male-only trait. A recent drone video shows a group of particularly handy narwhals using their tusks to stun fish with a quick strike before eating them. The discovery was quite a surprise to scientists who were using the drones to estimate current narwhal populations.
More research is needed to tease out how this discovery fits in with the larger picture of tusk evolution. In fact, the tusk might be used in multiple ways involving both natural and sexual selection, as is the case for African elephants. Skip to main content. Tusks of attraction To begin, not all narwhals have tusks, and a few, including one on display at the Sant Ocean Hall, have two. The narwhal tusk is actually one of two teeth. In males, the tusk protrudes from the upper, left lip.
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