A comparative analysis of the breeding biology of the Red‐billed Chough Pynhocorax pyrrhocorax and the Alpine Chough P. graculus coexisting in the Alps

Abstract

We compare the breeding biology of a small population of Red-billed Chough Pyrrhocorax pyrrhocorax with that of the Alpine Chough P graculus coexisting in the western Italian Alps. The analysis focused on nest site choice, timing of breeding, reproductive success and parental effort (assessed by means of behavioural indices such as food provisioning rates and time budgets inside and close to the nest). The Alpine Chough nested in a greater variety of sites: natural cliffs, windows of a dam, pot-holes and abandoned buildings; the Red-billed Chough used only natural cliffs. Laying dates also differed significantly, with the Red-billed Chough breeding one month earlier than its congener.Differences in the feeding ecology of those species might be responsible for the observed temporal partitioning, thus facilitating coexistence. Breeding success and reproductive behaviour were similar, and the species differed in only one out of eight breeding parameters. It is suggested that similar strong constraints on breeding behaviour have resulted in the similarities in behaviour seen in these species.

The altitudinal frontier in avian climate impact research

“…Water Pipit Anthus spinoletta , Rauter et al. 2002; Himalayan Accentor Prunella fulvescens , Lu 2006; Tibetan Ground Tit Pseudopodoces humilis , Ke & Lu 2009; choughs Pyrrhocorax spp, Laiolo & Rolando 2001; White‐tailed Ptarmigan Lagopus leucura , Martin & Wiebe 2004), few have considered variation in these demographic parameters in relation to altitude (e.g. Lu et al.…”

The foraging ecology of yellow-billed and red- billed choughs changed between two climatically different years

“…In such a condition, interspecific coexistence is enabled through reproductive and dietary segregation. The yellow-billed chough nests in a greater variety of sites and one month later than its congener 29 . The yellow-billed chough is a surface feeder that is mainly frugivorous from September to February (berries), herbivorous-omnivorous in March and April, and insectivorous from May to August (grasshoppers from July onward).…”

“…The yellow-billed chough is widespread in the European Alps (it is also known as the Alpine chough), where it has been extensively studied since the 1990s. Research on these breeds has focused on their breeding biology 23 , foraging behaviours 24 – 26 , local movements 27 – 29 , survival 30 and relationships with man 31 – 34 . In the western Italian Alps, the two species are sympatric and may also be present in the same habitat at the same time (syntopy).…”