Dasher, Dancer, Prancer, Endangered, Threatened, and Declining. Reindeer populations are on the decline, and if their numbers continue to diminish, Santa's sleigh pullers may only be remembered in Christmas folklore, rather than as handsome creatures roaming Arctic tundra.

With reindeer population already low across Northern latitudes, and especially low in China, genetic variance among mates becomes less and less. Their biggest risk now is inbreeding, which could result in genetic deteriorations and birth complications, furthering their decline.

As per John Muir’s ecosystem thinking: “when we try to pick out anything by itself, we find it hitched to everything else in the Universe", this loss of reindeer populations could actually exacerbate climate change. A Finnish study has confirmed that grazing reindeer can slow global warming by preventing solar heat absorption, which leads to climate change. The Turku University study reveals that areas where reindeer did not graze had higher levels of heat radiation, thanks to higher levels of shrubs and trees that absorbed heat.

A similar study in Sweden found that roaming reindeer counteract some of the effects of climate change, and can also prevent the climate-change-caused spread of invasive species in the Arctic tundra.

A reindeer is for Earth’s life, not just for Christmas cards.