Social information in nest colonisation and occupancy in a long-lived, solitary breeding bird

Abstract

Recent work increasingly reveals the importance of social information in individual dispersal decisions, population dynamics and conservation. Much of the knowledge gained to date comes from studies on short-lived and/or densely breeding species. In contrast, our understanding of the processes involved in nest-site selection for long-lived, solitary breeding species is insufficient. We increased nest-site availability by nest-box supplementation over a 5-year period in a population of a long-lived, solitary, secondary-cavity nesting bird, the European roller Coracias garrulus, breeding in natural cavities and human constructions. We tested the nest limitation and the inadvertent conspecific social information hypothesis in order to study the dynamics and mechanisms of abandonment of previously used nests and the colonisation of new ones. Our data lend support to the nest-limitation hypothesis both in terms of quantity-population and the size of breeding clusters increased, and suitability--the majority of pairs used and re-occupied nest-boxes. Nevertheless, the use of natural cavities did not decrease after 5 years. At the between-patch scale, rollers were revealed to colonise nest-boxes based on conspecific social attraction, namely distance to the nearest neighbour in the same season. Despite the unpredictability of patch productivity, at the within--patch scale, the selection of previously unoccupied cavities was consistent with the performance-based conspecific attraction hypothesis. Philopatry could account for the repeated use of cavities, because nests that were used for two successive years were more likely to also be reused in the subsequent season.

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

“…We found that the distance to the closest occupied nest-box or natural breeding hollow may affect nest-box occupancy. This finding supports the result of a Spanish study (Václav et al 2011), which showed that conspecific social attraction was important to the colonization of nest-boxes in the same season. Our results high- Table 3.…”

History and adaptation stories of the vertebrate fauna of southern Spain’s semi-arid habitats

“…A nest box installation program increased the population of rollers by 56% in four years during which natural holes were still used too (i.e. the population increase was not merely a change in the place of nesting) (Václav et al, 2011).…”

Natural cavity restoration as an alternative to nest box supplementation

“…Nest box supplementation has been reported to have economic, sociological, and scientific benefits (Møller ; Jedlicka et al ) as well as population increases of threatened species (e.g. Václav et al ; Berthier et al ; Kiss et al ). However, a number of shortfalls have also been reported: nest boxes are sometimes regarded as ecological traps (Schlaepfer et al ; Klein et al ; Rodríguez et al ) and, at the population scale, nest box programs may segregate spatially birds of various quality (Rodríguez et al ), leading to negative changes in local demography (Gauthier & Smith ; Petty et al ).…”