Skip to content

Research at St Andrews

Brood sex ratio varies with diet composition in a generalist raptor

Research output: Contribution to journalArticle


While sex allocation has been investigated productively at both population and family levels, as yet no general theory has been developed that is capable of linking processes at these two ecological scales, and very few empirical studies have examined cross-scale patterns. In Finnish northern goshawks (Accipiter gentilis), nestling sex ratio of local subpopulations is related to the spatial and temporal variation in the abundance of their principal avian prey, woodland grouse. Using data from an urban breeding population in Hamburg, Germany, I investigated: (1) whether brood sex ratio of goshawks varies with diet composition at the family level; (2) whether such variation could reflect adaptive adjustment; and (3) how family-level allocation can drive population-level patterns, such as those observed in Finland. Feral pigeons (Columba livia) were the most important prey species, with a pooled contribution to total diet of 36%. Brood sex ratio varied significantly with the proportion of pigeons in the breeding-season diet of pairs (increasing male bias). However, there was no evidence for sex-differential effects of diet composition, so it remains unclear whether the observed sex-ratio variation was an adaptive response. As all study pairs inhabited an (urban) environment where pigeons were unusually abundant, family-level sex-ratio adjustment caused a marked male bias in offspring sex ratio at the population level (male-biased nestling sex ratio in four of five years; pooled data: 60% males). This suggests that the large-scale variation observed in Finnish goshawk populations mirrors sex-ratio adjustment shown by individual families in response to small-scale environmental conditions. Apart from linking patterns empirically across ecological scales, this study is, to my knowledge, the first to demonstrate that family-level brood sex ratio varies with realized resource use (diet composition) in a raptor species. Previous studies either failed to find significant associations or, more commonly, violated theoretical assumptions by measuring environmental prey abundance (often integrated over large areas) rather than realized prey use of individual breeding pairs. I conducted a meta-analysis of offspring sex-ratio data from 17 goshawk populations across Europe to put my results into perspective. (c) 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 105, 937951.



Original languageEnglish
Pages (from-to)937-951
Number of pages15
JournalBiological Journal of the Linnean Society
Issue number4
Publication statusPublished - Apr 2012

Discover related content
Find related publications, people, projects and more using interactive charts.

View graph of relations

Related by author

  1. Inter-aviary distance and visual access influence conservation breeding outcomes in a territorial, endangered bird

    Flanagan, A. M., Rutz, C., Farabaugh, S., Greggor, A. L., Masuda, B. & Swaisgood, R. R., 4 Feb 2020, In : Biological Conservation. 242, 108429.

    Research output: Contribution to journalArticle

  2. Purifying selection in corvids is less efficient on islands

    Kutschera, V. E., Poelstra, J. W., Botero-Castro, F., Dussex, N., Gemmell, N. J., Hunt, G. R., Ritchie, M. G., Rutz, C., Wiberg, R. A. W. & Wolf, J. B. W., Feb 2020, In : Molecular Biology and Evolution. 37, 2, p. 469-474 6 p.

    Research output: Contribution to journalArticle

  3. Optimizing the use of biologgers for movement ecology research

    Williams, H., Taylor, L., Benhamou, S., Bijleveld, A., Clay, T., de Grissac, S., Demsar, U., English, H., Franconi, N., Gómez-Laich, A., Griffiths, R., Kay, W., Morales, J. M., Potts, J., Rogerson, K., Rutz, C., Spelt, A., Trevail, A., Wilson, R. & Börger, L., 1 Oct 2019, In : Journal of Animal Ecology. Early View

    Research output: Contribution to journalArticle

  4. Animal cultures matter for conservation

    Brakes, P., Dall, S. R. X., Aplin, L. M., Bearhop, S., Carroll, E. L., Ciucci, P., Fishlock, V., Ford, J. K. B., Garland, E. C., Keith, S. A., McGregor, P. K., Mesnick, S. L., Noad, M. J., Notarbartolo di Sciara, G., Robbins, M. M., Simmonds, M. P., Spina, F., Thornton, A., Wade, P. R., Whiting, M. J. & 5 others, Williams, J., Rendell, L., Whitehead, H., Whiten, A. & Rutz, C., 8 Mar 2019, In : Science. 363, 6431, p. 1032-1034 5 p.

    Research output: Contribution to journalArticle

  5. Population genomics and structure of the critically endangered Mariana Crow (Corvus kubaryi)

    Cortes-Rodriguez, N., Campana, M. G., Berry, L., Faegre, S., Derrickson, S. R., Robinette Ha, R., Dickow, R. B., Rutz, C. & Fleischer, R. C., 1 Mar 2019, In : Genes. 10, 3, 17 p., 187.

    Research output: Contribution to journalArticle

Related by journal

  1. Divergence and reproductive isolation between two closely related allopatric Iris species

    Volis, S., Zhang, Y-H., Deng, T., Dorman, M., Blecher, M. & Abbott, R. J., Jun 2019, In : Biological Journal of the Linnean Society. 127, 2, p. 377-389 13 p.

    Research output: Contribution to journalArticle

  2. Energetic costs in the coevolutionary relationship between bitterling fish and freshwater mussels

    Methling, C., Douda, K., Liu, H., Rouchet, R., Bartáková, V., Yu, D., Smith, C. & Reichard, M., 7 Nov 2018, In : Biological Journal of the Linnean Society. Advance Articles

    Research output: Contribution to journalArticle

  3. What is known and what is not yet known about deflection of the point of a predator's attack

    Humphreys, R. K. & Ruxton, G. D., 2 Mar 2018, In : Biological Journal of the Linnean Society. 123, 3, p. 483-495 13 p.

    Research output: Contribution to journalReview article

  4. Nonreceding hare lines: genetic continuity since the Late Pleistocene in European mountain hares (Lepus timidus)

    Smith, S., Sandoval-Castellanos, E., Lagerholm, V. K., Napierala, H., Sablin, M., Von Seth, J., Fladerer, F. A., Germonpré, M., Wojtal, P., Miller, R., Stewart, J. R. & Dalén, L., 1 Apr 2017, In : Biological Journal of the Linnean Society. 120, 4, p. 891-908

    Research output: Contribution to journalArticle

  5. Strong between-site variation in New Caledonian crows' use of hook-tool-making materials

    St Clair, J., Klump, B. C., van der Wal, J. E. M., Sugasawa, S. & Rutz, C., Jun 2016, In : Biological Journal of the Linnean Society. 118, 2, p. 226-232 7 p.

    Research output: Contribution to journalArticle

ID: 23996867