11.   But what happens when the prey species concentrate in lower elevations in winter?

12.   During the same time, there has been an increase in prey species for the cougars, including wild hogs, according to the Department of Fish and Game.

13.   Eagles also suffered because of declines in prey species, attributable to pollution and other human activities.

14.   The number of lions is up in the state and across the West, biologists said, resulting in unexpected consequences for bighorns and other prey species.

15.   Their main prey species have evolved with them, and so have developed formidable defenses.

16.   Photographs of tigers and prey species will then be analysed.

17.   From this, a minimum number of tigers, the relationship between tigers with prey species, and density, can be estimated.