Significance of the breeding season for autumnal nest-site selection by Tree Sparrows Passer montanus

The Tree Sparrow is one of the species exhibiting classical autumn sexual behaviour. Autumn nest selection by this species was studied in Central Poland, especially with respect to the history of nest-boxes in the previous breeding season. During the autumn display, Tree Sparrows constructed nests significantly more often in boxes that had been occupied in spring by conspecifics, but only rarely in empty boxes, in boxes where House Sparrow Passer domesticus, tits Parus sp., Pied Flycatcher Ficedula hypoleuca, Redstart Phoenicurus phoenicurus had nested, or in boxes used by hymenopterans. During the autumn display, Tree Sparrows showed a preference for boxes where nestlings had hatched. Nests with nestlings in the breeding season are a cue used in selecting nest site in the autumn sexual behaviour.