Winter breeding season of Brown-throated Martins Riparia paludicola in Morocco

Abstract

Uniquely among birds of coastal North Africa, Brown-throated Martins breed during the northern winter. Over ten years, the amount of rainfall in the six months before the breeding season was positively correlated with numbers of nests in November, and negatively with nest numbers in January. The evidence available suggests that winter breeding is most likely a response to the availability of insect food, acting through rain-induced vegetation growth, rather than a strategy to avoid predation, competition, or adverse weather conditions. This species may be more able than other species to breed in winter, because their deep nest tunnels provide protection against severe weather.