Savis warblers Locustella luscinioides have been studied intensively since 2000, during which a considerable number of blood samples were collected. The study of extra-pair paternity and sex allocation in this little-known species is likely to yield very interesting results due to the particularities of its life history (sexually monomorphic, simple monotonous song structure, multi-brooded), and provide very valuable data for comparative and meta analysis.
In this project, we will: (1) determine the rate of extra-pair paternity by using microsatellite alleles, (2) compare morphological, acoustic and behavioural features between the cuckolded males and the extra-pair sires, in order to study female sexual preferences, (3) evaluate the influence of heterozygozity and parental genetic similarity on extra-pair paternity, (4) determine the sex of hatchlings and evaluate whether environmental (eg. territory quality), intrinsic (eg. body condition of the female) or social factors (eg. social breeding system) affect the brood sex ratio in this species, and (5) determine if extra-pair offspring are male biased, which is expected if females select high quality or attractive males.
Neto, J. M., Hansson, B. & Hasselquist, D. 2011. Sex allocation in Savis Warblers Locustella luscinioides: multiple factors affect seasonal trends in brood sex ratios. Behavioral Ecology and Sociobiology 65: 297304.
Neto, J. M., Hansson, B. & Hasselquist, D. 2010. Low frequency of extra-pair paternity in Savis Warblers Locustella luscinioides. Behaviour 147: 14131429.