as an armchair ornithologist, i was recently pondering how surprising it was to see the same bird in both san diego and reykjavik. how is it possible that the arctic tern has such a wide range, i thought to myself. WELL, avid readers, you must wait no longer for the answer. it just so happens that the arctic tern has the longest known migration of any known animal.
its breeding grounds are in red, wintering grounds in blue, and migration patterns in green.
this kind of mobility ensures that arctic terns see two summers per year, and more sunlight than any other animal on earth. the terns fly 19,000 km per trip and accomplish these feats just a few months into their lives. this feat is incredible when you consider that many birds who migrate from central to north america, and fly across the gulf of mexico (no mean feat) have used up all stores of fat and will die without quickly regaining weight once they reach land again.
of course, the arctic tern is a product of the slow path of evolution; comparing shorter-migration birds with it is not like comparing a slothy couchbound person with an ultramarathoner, but it’s still incredibly impressive that this small bird is capable of so much. the largest terns weigh only 130g, which is less than a regular-sized can of tuna.
the arctic tern does almost everything it ever has to do in the air; it lands to breed every one to three years, depending on its breeding cycle. they migrate quite far off-shore, and take a meandering path to take advantage of prevailing winds, so the only time they are seen on land is generally during the breeding and hatching period.
arctic terns live for about twenty years, which seems like a really long time, but maybe that life span is due to their super aggressive behaviour. they are capable of repelling attacks from larger mammalian predators, like cats and foxes, and sometimes even attack humans. CAUSE THEY ARE METAL LIKE THAT