Advantages and disadvantages of coloniality in the swallow, Hirundo rustica

摘要: Abstract The advantages and disadvantages of coloniality in swallows, Hirundo rustica, were studied 1971–1975 1977–1985. Nest sites not limiting the local population density, swallows tended to aggregate actively at specific sites. Colony size was positively correlated with food abundance amount lee for prevailing westerly winds. per individual swallow decreased colony size, nestling feeding rates lower colonial than solitary swallows. Social foraging effects, measured as success relation number simultaneously conspecifics, important. Extra-pair copulations chases female by male nonmates common colonies. percentage time males spent mate guarding, frequency intraspecific nest parasitism guarding during egg laying increased size. Infanticide unmated occurred more frequently larger colonies, being an important mortality factor. Mite infection causing change between first second clutches predation averaged only 1·2%. A stuffed owl predator detected quickly Predation on fledglings adult may have been large Old mated young benefited from breeding Young females benefit breeding. asynchronous arrival pattern leave some early-arriving a deteriorating condition because resource has be divided individuals. All should stay their shortage means that these obtain all, if they move new colony. Many likewise making best bad job when