Effects of rearing conditions on natal dispersal processes in a long‐lived predator bird. Issue 13 (13th June 2018)

• Record Type: Journal Article
• Authors: Azpillaga, Maialen; Real, Joan; Hernández‐Matías, Antonio
• Is Part Of: Ecology and evolution. Volume 8:Issue 13(2018)
• Page Start: 6682
• Page End: 6698
• Publication Date: 2018-06-13
• Subjects: body condition -- Bonelli's eagle -- demographic heterogeneity -- natal dispersal -- raptor -- rearing conditions; Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.4165
• Languages: English
• ISSNs: 2045-7758

Abstract

Abstract: Natal or prebreeding dispersal is a key driver of the functioning, dynamics, and evolution of populations. Conditions experienced by individuals during development, that is, rearing conditions, may have serious consequences for the multiple components that shape natal dispersal processes. Rearing conditions vary as a result of differences in parental and environmental quality, and it has been shown that favorable rearing conditions are beneficial for individuals throughout their lives. However, the long‐term consequences of rearing conditions on natal dispersal are still not fully understood in long‐lived birds. In this study, we aim to test the following hypotheses to address the relationship between rearing conditions and certain components of the natal dispersal process in Bonelli's eagle ( Aquila fasciata ): (1) The body condition of nestlings depends on the quality of the territory and/or breeders; and (2) the survival until recruitment, (3) the age of recruitment, and (4) the natal dispersal distance (NDD) all depend on rearing conditions. As expected, nestlings reared in territories with high past productivity of chicks had better body condition, which indicates that both body condition and past productivity reflect the rearing conditions under which chicks are raised. In addition, chicks raised in territories with high past productivity and with good body condition had greater chances of surviving until recruitment. Furthermore, birds that have better condition recruit earlier, and males recruit at a younger age than females. At last, although females in good body condition exhibited higher NDD when they recruited at younger ages, this pattern was not observed in either older females or males. Overall, this study provides evidence that rearing conditions have important long‐term consequences in long‐lived birds. On the basis of our results, we advocate that conservation managers work actively in the promotion of actions aimed at improving the rearing conditions under which individuals develop in threatened populations. Abstract : Conditions experienced by individuals during their development, that is, rearing conditions, are known to carry strong consequences on multiple components of fitness, especially those that take place in the short‐term; however, much less evidence is available for long‐term effects of rearing conditions on individual's performance, including the components of natal dispersal processes. This work addresses the effect of rearing conditions on several components of the natal dispersal process in Bonelli's eagle ( Aquila fasciata ), a long‐lived predator bird that is endangered in Europe. Overall, our results illustrate that rearing conditions have a strong effect on the multiple processes that compose natal dispersal, but they also highlight that the determinants of these processes are complex and interact in a complex fashion.