Each spring, the U.S. Forest Service hires dozens of seasonal biologists to venture into remote Northwest forests on federal land and set up acoustic recorders to monitor for sounds indicating the presence of northern spotted owls, a threatened species.  There are only as many as 5,000 northern spotted owls left in the Northwest… The counting is crucial for preventing the owls’ extinction. But President Donald Trump ordered a hiring freeze that means the Forest Service cannot hire more than 40 seasonal scientists to count the owls, according to Taal Levi, an associate professor at Oregon State University who works on owl monitoring. The monitoring typically involves about 60 scientists working from central California to Canada, Levi said. It also means the agency will likely go without dozens more scientists needed to monitor threatened and endangered salmon, frogs and other fragile species….