Size-assortative nest choice by the Japanese fluvial sculpin in the presence of male-male competition |
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Authors: | T. Natsumeda |
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Affiliation: | Centre for Ecological Research, Kyoto University, Shimo-sakamoto 4-1-23, Otsu, Shiga 520-01, Japan |
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Abstract: | Nest choice by the Japanese fluvial sculpin Cottus pollux and its relationship to male reproductive success, was examined in a natural habitat, central Japan. The larger males tended to occupy the deeper nest cavities, suggesting size-assortative nest choice by the species. Stepwise regression analysis showed that cavity area was correlated positively to male reproductive success. Nest choice experiments without a competitive male indicated an absence of size-assortative nest choice, but larger males tended to choose a large nest when another male was present, suggesting that size-assortative nest choice by the species is attributable to male-male competition for large nests, such being related to a resource-defence polygynous mating system. |
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Keywords: | sculpin nest cavity male reproductive success male-male competition |
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