Factors Affecting Timing of Brood Desertion By Female Kentish Plovers Charadrius Alexandrinus

Abstract

[We investigated the factors affecting timing of female desertion in the Kentish plover Charadrius alexandrinus, in relation to a number of previously proposed hypotheses. Females deserted their broods on average 5.9 ± 1.4 (SE) days after hatching. Although timing of desertion was highly variable (0-30d), females deserted on the day of hatching in 9 out of 33 broods (median = 2.3 d). Timing of desertion was not related to mass or condition of the female at hatching, suggesting that energetic costs of incubation were not involved in determining desertion time. Similarly, there was no significant relationship between timing of desertion and the quality of the female's mate, either in terms of his mass, condition, or relative contribution to parental care prior to desertion. Desertion time was also unrelated to brood quality measured by weight, size or number of chicks at hatching. However, timing of desertion was negatively related to hatching date. We conclude that the strategy of desertion is time-constrained: females with early-hatching broods can afford to spend more time with their first brood (perhaps enhancing their expected gain from this brood) and still have sufficient time to desert, remate and rear a second brood. Females with later-hatching broods must desert this brood earlier in order to have time to rear a second brood successfully., We investigated the factors affecting timing of female desertion in the Kentish plover Charadrius alexandrinus, in relation to a number of previously proposed hypotheses. Females deserted their broods on average 5.9 ± 1.4 (SE) days after hatching. Although timing of desertion was highly variable (0-30d), females deserted on the day of hatching in 9 out of 33 broods (median = 2.3 d). Timing of desertion was not related to mass or condition of the female at hatching, suggesting that energetic costs of incubation were not involved in determining desertion time. Similarly, there was no significant relationship between timing of desertion and the quality of the female's mate, either in terms of his mass, condition, or relative contribution to parental care prior to desertion. Desertion time was also unrelated to brood quality measured by weight, size or number of chicks at hatching. However, timing of desertion was negatively related to hatching date. We conclude that the strategy of desertion is time-constrained: females with early-hatching broods can afford to spend more time with their first brood (perhaps enhancing their expected gain from this brood) and still have sufficient time to desert, remate and rear a second brood. Females with later-hatching broods must desert this brood earlier in order to have time to rear a second brood successfully.]