On the breeding ecology of the Dead Sea sparrow, Passer moabiticus.

Abstract

ABSTRACT The breeding biology of the Dead Sea sparrow was studied in two localities in the Rift Valley in Israel. The birds are monogamous and breed in loose colonies. Laying occurs from the end of March to the end of June. Mean incubation length is ca. 12 days and is significantly and negatively correlated with ambient temperatures. Mean clutch size ranges between 3.6 and 4.5 and decreases during the season. Hatching and fledging success range from 40% to 43% and from 27% to 28%, respectively. Nesting failures are caused by competition with other bird species, predation, desertion and infertility of eggs. Some females (9%-20%) relay after the young of the first clutch fledge; the mean time interval between laying the first eggs of the first and second clutches is 40–43 days. Sometimes females relay while still feeding young of the first clutch. The timing of laying and its relation to various environmental parameters is discussed, as well as the relationship between the breeding range extension of this s...