Butterflies are amazing creatures. Seemingly as delicate as tissue, they nonetheless can migrate thousands of miles and survive in frigid Arctic temperatures. Flying while freezing is only one of the unique traits of a newly-identified Arctic species called the Tanana Arctic (Oeneis tanana), which may owe its survival to the fact that it’s actually a hybrid of two ancient Alaskan butterflies.
To me it was surprising that no one had noticed this before.
That’s Andrew Warren, lepidopterist and author of a study in the current Journal of Research on the Lepidoptera (the order of insects that includes butterflies and moths) and the scientist who led the quest to correctly identify the Tanana Arctic butterfly. In 2010, he found a specimen labeled as the Chryxus Arctic butterfly at the Florida Museum of Natural History that didn’t look like a Chryxus Arctic. How could he tell? By the genitalia, of course.
In addition to the differences in genitalia, Warren found that this specimen was larger than normal and had unusual white spots in the underside of its wings. A Russian scientist confirmed that it had different DNA. But what was it?
Warren went to the spruce and aspen forests of the Tanana-Yukon River Basin in central Alaska and found additional specimens confirming that this was indeed a unique species - but one that closely resembled two others. DNA tests show that the Tanana Arctic is most likely a hybrid (butterflies are one of the few creatures where hybridization between related species occurs) of the Chryxus Arctic (O. chryxus) and the White-veined Arctic (O. bore).
This historic cross-mating occurred some time before the last ice age. Warren speculates that, as the rest of Alaska got frigid, the Tanana Arctic and White-veined Arctic remained in Beringia, an unglaciated region including the land mass that once connected what is now Alaska with Asia. Meanwhile, the Chryxus Arctic flew south to the Rocky Mountains.
Warren looks at the Tanana Arctic as sort of a ‘butterfly in the coal mine’ – butterflies are early indicators of climate change.
This butterfly has apparently lived in the Tanana River valley for so long that if it ever moves out, we'll be able to say 'Wow, there are some changes happening. This is a region where the permafrost is already melting and the climate is changing."
From the tiniest creatures come the biggest revelations. No wonder you feel bad when they smash into your windshield.