There are many predators eager to rob nests of their eggs and chicks including jays, crows, snakes and mammals. Nesting birds take great pains to keep their brood safe, choosing hidden locations and acting elusive and inconspicuous around their nests. Many birds, like bushtits, also adorn their nests with lichen and plant materials that mimic the immediate surroundings. Perhaps this nest was a little too out-in-the-open and not camouflaged well enough.
