Dung beetles in an avian-dominated island ecosystem: feeding and trophic ecology.

摘要: Globally, dung beetles (Scarabaeidae: Scarabaeinae) are linked to many critical ecosystem processes involving the consumption and breakdown of mammal dung. Endemic New Zealand (Canthonini) an anomaly, occurring at high abundance low diversity on island archipelago historically lacking terrestrial mammals, except bats, instead dominated by birds. Have Zealand’s evolved specialise bird or carrion, have they become broad generalist feeders? We test dietary preferences analysing nitrogen isotope ratios wild performing feeding behaviour observations captive specimens. also use carbon stable isotopes determine if beetle Saphobius edwardsi will consume marine-derived carrion. Nitrogen indicated trophic generalism in this was supported behavioural where a range food resources were utilised. Alternative resource further illustrated experimentally signatures S. edwardsi, individuals provided with decomposed squid had δ15N δ13C values that shifted toward associated marine diet. Our findings suggest that, absence native resources, diet This may include as seabird colonies present forests before arrival humans. has probably enabled persist indigenous ecosystems despite decline birds introduction species.