biostudies-literatureUnknown2(6)Gronstol GResource polygyny incurs costs of having to share breeding resources for female breeders. When breeding with a relative, however, such costs may be lessened by indirect fitness benefits through kin selection, while benefits from mutualistic behaviour, such as communal defence, may increase. If so, females should be less resistant to sharing a territory with a related female than with a non-related one. We investigated whether kin selection may lower the threshold of breeding polygynously, predicting a closer relatedness between polygynous females breeding on the same territory than between females breeding on different territories. Northern lapwings, Vanellus vanellus, are suitable for testing this hypothesis as they are commonly polygynous, both sexes take part in nest defence, and the efRoyal Society open science140409https://www.ebi.ac.uk/biostudies/studies/S-EPMC4632532biostudies-literatureKin selection and polygyny: can relatedness lower the polygyny threshold?PMC4632532Gronstol GBlomqvist DWagner RHPauliny AfalseKin selection and polygyny: can relatedness lower the polygyny threshold?Resource polygyny incurs costs of having to share breeding resources for female breeders. When breeding with a relative, however, such costs may be lessened by indirect fitness benefits through kin selection, while benefits from mutualistic behaviour, such as communal defence, may increase. If so, females should be less resistant to sharing a territory with a related female than with a non-related one. We investigated whether kin selection may lower the threshold of breeding polygynously, predicting a closer relatedness between polygynous females breeding on the same territory than between females breeding on different territories. Northern lapwings, Vanellus vanellus, are suitable for testing this hypothesis as they are commonly polygynous, both sexes take part in nest defence, and the ef2015-01-01T00:00:00Z2015 Jun2025-04-21T20:22:21.558Z2019-03-27T02:01:20ZS-EPMC46325322654356810.1098/rsos.140409