New legal action aims to head off a Trump administration plan to open up to 24m acres of federal lands to cattle grazing, which opponents characterized as a gift to big agriculture and said could cause a spike in deaths among already imperiled wolves, grizzlies, steelhead salmon and other wildlife. The plan also calls for opening up parts of Grand Canyon national park, and other sensitive landscapes. Cattle destroy critical habitats for wildlife because they strip land bare of essential vegetation and pollute streams with feces, urine, sediment and carcasses. Meanwhile, park rangers and ranchers often kill grizzly bears and other predators who prey on cattle, despite that ranchers and the government pushed the cattle into the predators’ home range. The degree to which livestock grazing degrades ecosystems makes it a top threat to animals and plants at risk of extinction, environmental advocates say. These issues exceed the combined impacts of logging and mining on protected species.…