A high incidence of non-cavity nesting in an introduced population of House Sparrows suggests that the species should not be constrained by cavity-nest site availability

Elizabeth Louise Sheldon,Simon Charles Griffith

doi:10.1186/s40657-017-0087-0

Abstract

BackgroundThe House Sparrow (Passer domesticus) has undergone dramatic population declines in many parts of Europe. It has been widely hypothesised that a lack of cavity nest sites has contributed to this decline. However the idea of the House Sparrow being nest site limited is somewhat incompatible with the long history of nest site plasticity in the species.MethodsThe nest-site selection in a population of non-native House Sparrows introduced to Australia from Europe just over 150 years ago was characterised. The prevalence of non-cavity nesting was quantified, and nest-site selection in terms of landscape and nesting structure were described.ResultsFlexible nesting behaviors were reported over a range of different landscapes and a surprisingly high rate of nesting in vegetation (43%) was documented. Most nests found in vegetation were not in cavities, but were woven into the foliage and supported by branches and stems.ConclusionThe high rate of vegetation nesting indicates that in this introduced population, the House Sparrow is unlikely to be constrained by cavity-nest site availability. The high degree of nest site plasticity in the Australian population may suggest that European House Sparrows have the potential to shift away from their proclivity for cavity nests. Future work in Europe should examine the incidence of non-cavity nesting in House Sparrows more closely, and perhaps reconsider the idea that House Sparrows are nest-site constrained.

Highlights

The House Sparrow (Passer domesticus) has undergone dramatic population declines in many parts of Europe
Background the House Sparrow (Passer domesticus) has been introduced to many parts of the world, and is one of the most globally distributed of all birds (Pimentel et al 2005; Shochat et al 2010), it has become a species of conservation concern in parts of its native range (Summers-Smith 2003; Robinson et al 2005)
The idea of the House Sparrow being nest site limited is somewhat incompatible with the long history of nest site plasticity in the species

Summary

Introduction

The House Sparrow (Passer domesticus) has undergone dramatic population declines in many parts of Europe. The House Sparrow (Passer domesticus) has been introduced to many parts of the world, and is one of the most globally distributed of all birds (Pimentel et al 2005; Shochat et al 2010), it has become a species of conservation concern in parts of its native range (Summers-Smith 2003; Robinson et al 2005). An increasing number of studies have cited nest site limitation as the leading (Dandapat et al 2010; Balaji 2014; Nath et al 2016) or contributory cause of House Sparrow population declines (Summers-Smith 2003; Goyal 2005; Anderson 2006; Ghosh et al 2010; Balaji et al 2013; Singh et al 2013; Paul 2015). The idea of the House Sparrow being nest site limited is somewhat incompatible with the long history of nest site plasticity in the species.

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