Reasons why predators cannot be inferred from nest remains

Abstract

I present reasons that preclude the identification of nest predators from nest remains: interspecific overlap and intra-specific variation in patterns of nest destruction, unexpected predators, egg size, stage of development, experience of researchers, partial nest depredation, multi-predator visits, and parental activity at depredated nests. Because many of these problems may act simultaneously, I suggest that further attempts at validating this subjective field technique be abandoned, and instead that researchers and managers invest their time and resources in objective methods of predator identification, possibly through the use of predator identification devices.