Breeding biology of the House Martin Delichon urbica in Algeria

Abstract

Dates of egg laying, clutch size, the numbers of hatchlings and fledglings, and egg dimensions were studied in Annaba, Algeria in 2004-2005. The onset of laying is related to the end of the wet period and shows some inter-year variation. 38-45% of breeding pairs produce two broods per year. Mean clutch size declines with the progress of the breeding season. Mean values vary between the first (4.7 eggs) and second clutch (3.5 eggs) but not between years. Hatching and fledging success is relatively low in comparison with other Western Palearctic populations, probably because of environmental constraints operating at the southern edge of the House Martin breeding area. The relatively small size of Algerian House Martin eggs fits the general geographic pattern of variation.