An unusual alliance of Republican lawmakers and animal rights advocates, together with others, is creating storm clouds for a plan to protect one threatened owl by killing a more common one. Last August, the U.S. Fish and Wildlife Service approved a plan to shoot roughly 450,000 barred owls in California, Oregon and Washington over three decades. The barred owls have been out-competing imperiled northern spotted owls in the Pacific Northwest, as well as California spotted owls, pushing them out of their territory. Supporters of the approach — including conservation groups and prominent scientists — believe the cull is necessary to avert disastrous consequences for the spotted owls. Last month, The Times has found, federal officials canceled three owl-related grants to the California Department of Fish and Wildlife totaling roughly $1.1 million, including one study that would remove barred owls from over 192,000 acres in Mendocino and Sonoma counties.