Living organisms respond to climate change in two ways, by evolutionary adaptions and phenotypic plasticity, also known as an observable change.
When two or more clearly different phenotypes exist in the same population of a species, the species is called polymorphic.
That’s happening now, according to researchers, to reindeers in the Arctic.In the Arctic island near the North Pole called Svalbard, a chain of islands north of Norway, have lost about 8 per cent of their body weight, dropping from 55 kg (121 pounds) to 48 kg (196 pounds).
The drop in weight happened in the 1990s when scientists first noted that temperatures were rising.
Warmer summers are great for reindeer but winters are getting increasingly tough,” Professor Steve Albon, an ecologist at the James Hutton Institute in Scotland who led the study with Norwegian researchers, said in the Guardian.
Some reindeer starve and females often give birth to stunted young.
In summer, however, plants flourish in a food bonanza that ensures healthy females more likely to conceive in autumn. The wild herd studied had expanded to about 1,400 animals from 800 since the 1990s.
While evolutionary adaptation in animals with long generation times is not likely to keep pace with the ongoing rapid warming of the Arctic, the researchers demonstrates that Arctic ungulates are capable of behaviorally buffering climate related changes in their habitat.
Icing events triggered an immediate increase in Svalbard reindeer movement rates with displacement toward less icy ranges with less severe feeding conditions, lower body mass loss, lower mortality index, and higher fecundity.