Loose nesting aggregation in the Red-necked Nightjar, Caprimulgus ruficollis

Full article

Published:

Volume 48(1), June 2001. Pages 11-18.

Language:

English

Keywords:

Caprimulgiformes, Caprimulgus ruficollis, coloniality, nest aggregation, Red-necked Nightjar

Abstract:

The existence of loose nest aggregations in the Red-necked Nightjar Caprimulgus ruficollis is scarcely documented and very little is known about it. Here, we study whether the existence of loose nest aggregations in this species corresponds to a colonial behaviour or it is just related to habitat availability. We carried out a study in two different sites of Córdoba (Southern Spain) with apparently different patterns of nest dispersion. At each site we recorded: distance between neighbouring nests, breeding delay in relation to the earliest nest, defensive response, tolerance to conspecifics and breeding success. Our results show that nests seem to be aggregated in one site and isolated in the other. Compared to isolated nests, aggregated nests show a smaller breeding delay, a stronger communal defence response, a higher tolerance of intrusions and a breeding success similar to isolated nests. We failed to find benefits/costs typical of coloniality, indicating that nest aggregations are a response to habitat features.