Female House Martin Delichon urbica provisions chicks at nests in two separate subcolonies

Abstract

An individually colour-ringed House Martin Delichon urbica, molecularly confirmed to be a female, after attending a first brood in early July 2007, became engaged with two second broods at the same time, one with the original mate of the first brood. The two nests were at opposite sides of the same building and not within each other's sight. During simultaneous observations on 1 September, the female was feeding large nestlings at each of the two nests, alternating between bouts of repeated feeds. This behaviour by a female with perhaps below-average survival prospects (she had a slightly damaged wing tip and a low weight at first capture) can be interpreted as a case of helping relatives or polyandry.