One definition of the word 'lurk' is to lie in wait in a place of concealment. Among those birds that spend time along Louisiana bayous, one species in particular can be said to exhibit this behavior as a matter of habit. Rain crows, often heard but less often seen, are bona fide lurkers as they perch with hunched shoulders that belie a long, graceful neck in a pose that for all the world appears to me an expression of guilt.