Variation der Geschlechterratio bei Kiebitzen auf Madagaskar: experimenteller Test der Rolle von Parasiten und Immunfunktion

• Antragsteller: Professor Dr. Oliver Krüger
• Fachliche Zuordnung: Biologie des Verhaltens und der Sinne ; Evolution, Anthropologie
• Förderung: Förderung von 2013 bis 2024
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 233740704

Animal breeding systems are immensely diverse, and the origin and maintenance of this variation is one of the fundamental issues in evolutionary biology. Recent theoretical models suggest that breeding systems should be intimately linked to demographic properties of populations, although tests of this prediction in natural vertebrate populations are lacking. We propose to quantify the demography and breeding systems of small plovers Charadrius. Results of a pilot study on one of the proposed study species suggest that a key demographic parameter, adult sex ratio (ASR), is heavily biased toward males (6 males to 1 female), and that this species exhibits male only parental care and polyandry, consistent with theoretical predictions. This proposal aims to combine field ecology and behaviour with demographic modelling to estimate ASR in three plover species in Madagascar, the black-banded plover (Charadrius thoracicus), white-fronted plover (C. marginatus) and Kittlitzs plover (C. pecuarius). Pilot data suggest that the former two species are monogamous with biparental care of the young, whereas Kittlitzs plover is polygynous with uniparental care of the young. Using the most detailed field study of these species so far, we propose to quantify mating system (genetic and social) and parental care (incubation and brood care) in all three species. Sex ratio and survivorship will be measured for offspring, immatures and adults and the resulting data will feed into demographic models. Theoretical models predict that populations with male biased ASR should exhibit male only care and polyandry, whereas populations with unit sex ratio (1 male to 1 female) would exhibit biparental care coupled with genetic and social monogamy. This project is significant for three reasons:1) It will use comparative experiments and demographic analyses to estimate ASR in natural populations of closely related species in which pilot studies have provided exciting results. Collectively, these works will comprise the first field-based tests of theoretical models of ASR and parental behaviour. 2) The project will collect a large dataset on the mating systems of 3 Malagasy bird populations, and using these data and the DNA samples (see below), we plan to build further models for sex role evolution. 3) Finally, beyond evolutionary biology, this work is important for population ecology and conservation biology. Birds with skewed sex ratios are often globally threatened, so our results will provide excellent baseline data towards understanding population trajectories of threatened species.

• DFG-Verfahren: Sachbeihilfen
• Internationaler Bezug: Großbritannien
• Mitverantwortliche: Dr. Nayden Chakarov; Professor Dr. Joseph Hoffman
• Kooperationspartner: Professor Tamás Székely, Ph.D.