The presence of predatorial burrowing owls on the Farallon Islands deep into winter is harming the survival of adult ashy storm petrels, according to a study published by Point Blue Conservation Science. Owls arrive in the Farallones around mid-October, when the islands’ invasive house mouse population is at its peak. Several opportunistic owls stay to feast on one of the highest reported mouse densities for any island in the world. When the mouse population crashes…