Do artificial nests reveal relative nest predation risk for real nests?

Abstract

Present knowledge of the effects of nest predation on spatial distribution, habitat selection and community structure of birds is to a large extent based on results from experiments with artificial nests. Although nest predation risk is likely to differ between artificial and real nests, most previous studies of nest predation using artificial nests have been lacking a proper control. We investigated whether predation rates on artificial nests predicted those on real nests by simultaneously comparing the fate of real and artificial nests (containing quail Coturnix coturnix and plasticine eggs) in 92 territories of the northern wheatear Oenanthe oenanthe in 1996. We also investigated whether risk for artificial nests was related to relative average risk for real nests in these territories (based on data collected two years before and two years after the experiment). Nest predation on artificial nests did predict relative predation risk for real nests only when quail egg depredation was used as the criterion for artificial nest predation. Despite plasticine egg depredation being the most common type of predation it was not associated with predation risk for real nests. Small mice and vole species dominated among cases with only plasticine egg depredation, while predatory mammals and snakes destroyed most quail eggs in artificial nests and most eggs in real wheatear nests. The results suggest that artificial nests may only predict the risk for real nests when the nest predator species are similar among the two types of nest. Furthermore, our data suggest that small mice and vole species rarely depredate nests of mid‐sized passerine birds. Our results cast doubt on many previous conclusions based on experiments with artificial nests, since predation risk for such nests is likely to be uncorrelated with risk for real nests due to nest‐type‐specific differences in nest preying species.

Ground Nesting in Recultivated Forest Habitats — A Study with Artificial Nests

“…As Pärt & Wretenberg (2002) suggested, nest predation on artificial nests did predict relative predation risk for real nest only when quail egg depredation was used as the criterion for artificial nest predation.…”

“…Davison & Bollinger (2000) suggest that future artificial nests studies should use nests and eggs that mimic the real nests and eggs of the target species as closely as possible. According to Pärt & Wretenberg (2002) artificial nests may only predict the risk for real nests when the nest predator species are similar among the two types of nest. Despite these, the number of artificial nest studies addressing ecological questions has continued to grow exponentially (Moore & Robinson 2004).…”

Using artificial nests to explore predation by introduced predators inhabiting alpine areas in New Zealand

“…Therefore, the motives of these omnivorous animals in destroying a nest may not be those of a predator. This problem may disrupt any relationship between artificial nest predation and real nest predation (Part & Wretenberg 2002). also, this result raises the possibility that the possums in the Borland Valley that left imprints on plastilina eggs may not have taken the paired chicken eggs there either.…”

Predation on artificial nests in open habitats of central Brazil: effects of time and egg size

“…However, artificial nests differ from natural nests in important ways, including appearance (nest shape and color), scent, egg size and parental activity (Major & Kendal 1996), which may result in biased estimates of true predation rates (Roper 1992, Haskell 1995, Maier & DeGraaf 2000. These problems have directed the use of artificial nests to test more restricted hypotheses such as to predict relative impacts between habitat types, or for comparisons between artificial and natural nests (Pärt & Wretenberg 2002, Batáry & Báldi 2005, Boyle 2008, Ryder et al 2010. The effectiveness of artificial nest experiments depend on local and specific agents, and each characteristic of the nest must be tested before local hypotheses on conservation and ecological patterns are evaluated (Major & Kendal 1996).…”