Sentences with phrase «annual predation rates»

In their recently released book, The American Bird Conservancy Guide to Bird Conservation, ABC changes tack a bit — using what the authors call «conservative» estimates of the outdoor cat population and annual predation rates, for example, to arrive at their figure of «532 million birds killed annually by outdoor cats.»

where npc is the number of owned cats in the contiguous United States, pod is the proportion of owned cats granted outdoor access, pph is the proportion of outdoor owned cats that hunt wildlife, ppr is the annual predation rate by owned cats, cor is a correction factor to account for owned cats not returning all prey to owners, nfc is the number of un-owned cats in the contiguous United States, pfh is the proportion of un-owned cats that hunt wildlife, and fpr is the annual predation rate by un-owned cats.