Breeding biology of a Kentish Plover (Charadrius alexandrinus) population in an inland saline lake

Full article

Published:

Volume 43(1), June 1996. Pages 69-85.

Language:

English

Keywords:

breeding biology, brood desertion, Charadrius alexandrinus, parental care, mating system, sequential polygamy.

Abstract:

We studied the breeding biology of Kentish Plovers (Charadrius alexandrinus) in Fuente de Piedra lake (southern Spain) in 1991 and 1992. Breeders showed sexual dimorphism in tarsal length and body mass; body mass decreased throughout the breeding season only in males. Laying dates spanned 88 days in 1991 and 110 in 1992. Eggs deposited in the late nesting season were larger than those in the beginning of the season. Females incubated during daytime and males during the night. Apparent clutches of 1-2 eggs occurred mostly late in the nesting season and reflect a high incidence of partial predation (recorded in 17% of 288 2-3 egg clutches). Nest predation increased in the course of the breeding season, and only 19% of all clutches produced chicks. Variables measured for each nest site (nest cover, distances to water and to nearest neighbour) did not influence nest predation. Kentish Plover pairs that lost clutches usually renested together, on average 11-24 days after loss of their previous clutch. The body masses of females were similar between first and subsequent replacement nestings. Biparental care of chicks lasted longer than in several other populations of Kentish Plovers. When the chicks were 15-20 days old one of the adults, usually the female, deserted the brood. Gull-billed Terns (Gelochelidon nilotica) preyed on chicks up to 16 days of age. Both sexes showed antipredator behaviours (alarm calls, mobbing). Possibly, the greater maternal protection of the brood at Fuente de Piedra compared to other breeding locations results from an interrelationship between high predation pressure and type of predators, since mobbing of Gull-billed Terns by adult plovers was effective in deterring the terns. After deserting broods, some females mated to new males (sequential polyandry). Sequential polygyny was recorded in males that fledged chicks early enough for a subsequent nesting attempt. We propose that the duration of the breeding season and high clutch failure rates constrained the frequency of sequential polygamy in our population.