Believe it or not, pigeons are related to doves (both hail from the columbidae  family of birds) but to many co-op and condo buildings, the former are not at  all symbolic of peace. Quite the contrary. Although rats, mice, cockroaches,  and now bedbugs get most of the bad press involving urban pest animals, pigeons  are pests, too, perching on any overhanging surface, cooing and chirping and  leaving pigeon-fluff and droppings everywhere.  

 An overabundance of birds result in more than just a messy, unsightly situation;  if bird waste accumulates on air vents, window-mounted air conditioning units,  or intake grates, building residents may be at risk for a number of extremely  unpleasant—even life-threatening—parasitic ailments.  

 The Grey Bird of Messiness

 Even a city like New York teems with avian life. But for all the bevy of birds  in the five boroughs, pigeons are the ones that cause the biggest headaches.  But why pigeons and not geese for example, or finches, or barn swallows?  

 The first reason is that, like many native New Yorkers, pigeons don’t like to leave. “They don’t migrate,” says Heath Waldorf, vice president of Bell Environmental in Parsippany, New  Jersey. “Lost of other pest birds migrate—geese, blackbirds, sparrows. But pigeons are here all year round.”  

 The species of pigeon in New York, Waldorf says, originated in England, where  they perched high on the famed cliffs of Dover. This is another reason the  birds love New York: the high-rise buildings remind them of home.