Differences in predatory pressure on terrestrial snails by birds and mammals

Journal of biosciences

Piotr Tryjanowski³  Adrian Surmacki¹  Paulina Olborska³  Zuzanna M Rosin1² 

[1] Department of Avian Biology and Ecology, Faculty of Biology, Adam Mickiewicz University, Umultowska 89, 61-614 PoznaÅ„, Poland$$;Department of Cell Biology, Adam Mickiewicz University, Umultowska 89, 61-614 PoznaÅ„, Poland$$;Department of Behavioural Ecology, Adam Mickiewicz University, Umultowska 89, 61-614 PoznaÅ„, Poland$$

关键词: Apodemus sylvaticus;    Cepaea nemoralis;    natural selection;    shell size;    Turdus merula;    Turdus philomelos;   

DOI  :  

来源: Indian Academy of Sciences

【 摘 要 】

The evolution of shell polymorphism in terrestrial snails is a classic textbook example of the effect of natural selection in which avian and mammalian predation represents an important selective force on gene frequency. However, many questions about predation remain unclear, especially in the case of mammals. We collected 2000 specimens from eight terrestrial gastropod species to investigate the predation pressure exerted by birds and mice on snails. We found evidence of avian and mammalian predation in 26.5% and 36.8% of the shells. Both birds and mammals were selective with respect to snail species, size and morphs. Birds preferred the brown-lipped banded snail Cepaea nemoralis (L.) and mice preferred the burgundy snail Helix pomatia L. Mice avoided pink mid-banded C. nemoralis and preferred brown mid-banded morphs, which were neglected by birds. In contrast to mice, birds chose larger individuals. Significant differences in their predatory pressure can influence the evolution and maintenance of shell size and polymorphism of shell colouration in snails.

【 授权许可】

Unknown