Biologist Eric Post said data show the timing of peak food availability no longer corresponds to the timing of caribou births, the university said Friday in release.

The study, conducted in collaboration with Mads Forchhammer at the University of Aarhus in Denmark, will be published in the July issue of the Philosophical Transactions of the Royal Society of London.

With temperatures rising, pregnant females find that the spring plants on which they depend to survive have already begun to decline in nutritional value. Post said the plants are peaking dramatically earlier.

"Spring temperatures at our study site in West Greenland have risen by more than 4 degrees Celsius over the past few years," he said. "As a result, the timing of plant growth has advanced, but calving has not."