Monitoring bears as they hunt seals through the ice and snow of their Arctic environment is no simple task. But thanks to technological advances like DNA analysis and satellite tracking, surveying polar bears is now a little bit easier. University of Minnesota biologists recently used a satellite to take a polar bear head count, for example, identifying about a hundred bears in northeastern Canada.
By analyzing DNA and molecules like hormones, scientists can not only identify specific animals, but can also get an overall indication of the animals' health. Noninvasive samples, like those taken from droppings or footprints, pose less risk to animals than tissue specimens - and are frequently cheaper to collect, too. (Although, as the Guardian points out, biologists aren't sure how stale tracks can get and still provide usable DNA.)
The footprint method "would be an invaluable tool for conservation biology," says the WWF's Arnaud Lyet. "At present, researchers use expensive, invasive techniques to track the population size and health of wildlife such as polar bears. Using footprint DNA, we could dramatically cut the investment required, so monitoring populations could be done more easily."