, Aug. 28 -- Wildlife may be responding to the physical presence of people much more than scientists previously understood, according to a new study that tracked more than 4,500 animals across the United States.

Researchers from the University of California, Santa Barbara, the Smithsonian's National Zoo and Conservation Biology Institute, and Yale University combined GPS data from 37 animal species with anonymised cellphone location data.

The study, published in the journal Science, found that animals respond differently to human activity depending on the species and how much the surrounding landscape has already been changed by people.

The findings could help scientists develop more effective and species-specific approaches to wildlif...