Scientists studying grey wolves in Yellowstone national park have developed a method to predict how animals will respond to climate change.
The discoveries gleaned from the study, published on Thursday in Science, could eventually help scientists discover which animals are more resilient to climate change – and which would be at most immediate risk of extinction.
"We now have the tools to determine how wolves would react to climate change," said Tim Coulson, a professor of life sciences at Imperial College London, who led the study. "With any luck, in the future we can apply the methods developed from the wolves down to small mites or to large herbivores."
The study used data that is already routinely collected on radio-collared wolves to get a glimpse of some basic responses to a changing environment – population numbers, genetics, body size, and the timing of key events in the wolf life cycle, such as when they first have pups.
It also took account of changing genetics in the wolves' coats. Unlike in Europe, the grey wolves of Yellowstone actually have black or grey coats.
Research scientists from the US department of the interior, Utah State University and the University of California travelled over the park by helicopter, tracking wolf packs. They shot the wolves from the air with darts, before descending to weigh them and take blood samples. The scientists collected more than a decade's worth of data from the 280 wolves living in the park.
The animals were re-introduced to Yellowstone in the mid-1990s after being driven to extinction more than 70 years earlier. White settlers to the Rocky Mountain West in the late 19th and early 20th centuries shot, poisoned and trapped wolves at will – an extermination effort encouraged by the federal government, which was interested in promoting livestock interests.
The last wolf was reported shot in the area around Yellowstone in the 1920s.
Since their re-introduction, however, the wolf population has exploded in the areas around the park. Wildlife officials estimate there are now about 1,700 wolves in Montana, Idaho, Wyoming, Oregon and Washington – about five times more than envisaged under the original recovery plan.
Scientists have been working for several years on how to insulate animals from a changing climate. Some animals will be constantly on the move, up hill and to cooler locations at a rate of about a quarter of a mile a year according to one study, in search of suitable homes.
Other animals will run out of space, and die out. Still others may successfully adapt, growing bigger or smaller to suit their new conditions.
The Science study allows researchers to look at a number of key variables, including growth rate, fertility, and life span. "One of the ways people could take our framework is to ask whether animals that are able to adapt body size, or coat colour, are likely to change sufficiently fast so that the animals can cope with change," Coulson said.
The latest study does not go into sufficient detail to predict how the gray wolves of Yellowstone will react to a smaller snow pack in the Rocky Mountains, or changes in the population of elks that are their prey, or diseases that may be brought by climate change, Coulson said. That will require further research.
But he said the new computer model developed in the study allows researchers to study for the first time how animals react to climate change, both in terms of behaviour – such as the age they first reproduce – and genetics – such as whether it has black or grey coat.
And he said it would have applications far beyond wolf populations.
"In reality we can apply the methods we developed across a range of animals and behaviours," he said.