Exterior nest-boxes may negatively affect Barn Owl Tyto alba survival: an ecological trap

Abstract

SummaryNest-site reduction has played a significant role in the decline of Barn Owl Tyto alba populations throughout Europe and North America. Techniques of nest-site augmentation, involving the provision of nest-boxes, have been widely used in a range of species of conservation concern, including falcons, eagles, parrots, owls and cavity-nesting ducks. A common method of Barn Owl conservation is the placement of nest-boxes on church towers. Despite the usefulness of nestboxes, several studies have shown that there may be associated disadvantages and that nestboxes may even act as 'ecological traps'. The purpose of this research was to compare the survival rate of owlets hatched in nest-boxes with those hatched in the more ''natural'' environment of church towers. Survival time analysis elucidated that owlets developing in nest-boxes had significantly lower survival than those hatched in church towers. This difference was most obvious after the parent-dependent period of the life history. Surprisingly, the length of time from hatching to the onset of winter had no effect on the survival of the owlets, even though the accumulation of sufficient body reserves and acquisition of hunting experience are thought to be important in determining survival during the critical first winter of life. We propose possible causes for the negative effects of nest-boxes and recommend some modifications to the priorities of Barn Owl Action Plans, e.g. partial reopening of buildings instead of nest-box installation. This paper emphasizes the importance of considering revision of Species Action Plans in the case of other endangered species where conservation is based on nest-site supplement (e

The effectiveness of nest-box supplementation for the conservation of European rollers (Coracias garrulus)

“…This method is efficient in the conservation of secondary cavity-nesters and may contribute to the increase of population size in threatened bird species (Newton 1994, Gottschalk et al 2011, Olah et al 2014. Although nest-box provisioning is typically helpful for bird conservation, it should be applied with caution, as nest-boxes in low-quality habitats may serve as ecological traps and make unsuitable sites attractive for birds with decreased reproductive success and increased mortality (Klein et al 2007, Rodriguez et al 2011. Providing artificial nesting places is usually labour-saving and costly, therefore conservation programmes need to evaluate their efficiency.…”

Interspecific and intraspecific spatial separation by birds breeding in nest boxes

“…However, providing nest boxes in marginal habitats may be creating an ecological trap for the subset of the population forced to breed in a marginal habitat for foraging or has increased predation risk (Mänd et al 2005, Klein et al 2007, Rodríguez et al 2011. Moreover, the long-term value of nest boxes as breeding cavities has recently been questioned because boxes have lower humidity and poorer insulation than natural cavities in trees (Maziarz et al 2017).…”

“…Provision of nest boxes can allow an increase in breeding density in some, but not all, habitats (Mänd et al 2005, Camprodon et al 2008. However, provision of nest boxes can also lead to an ecological trap because birds may be "tied" to breeding in a suboptimal habitat (Mänd et al 2005, Klein et al 2007, Rodríguez et al 2011). …”

Breeding ecology of tits using artificial nest boxes in coniferous and deciduous forests in Mt. Namsan, Seoul Metropolitan, Korea

“…Provisions of artificial nest boxes have also been used as a conservation tool for several species of concern (Poole and Gill 2002;Klein et al 2007;Son et al 2012). Given that cavities are a major cue for the nest-site selection of cavity-nesting birds, abundant artificial nest boxes should make an area very attractive for many of these birds.…”