Actually, war is often quite beneficial to animal populations -- when
humans are slaughtering one another they generally stop slaughtering other
species. Fishery populations on the Georges Bank, for example, rebounded
during the war of 1812 because fishers could not venture out without fear
of capture. Similarly, game populations apparently increased during the
Civil War. Total war, of course, may well be a different matter. I doubt
that game populations in Europe were benefitted by WWII.

Dale Goble
Moscow