Nest Concealment and Nest Defence by
Two Passerines
Protection of broods from predators using
aggressive behaviour of other species is one of the most unusual
strategies used by birds to evade predation. One such strategy is the
creation of protective nesting association in which one or more species
relate and directly benefit from nesting within the protective umbrella
created by other species. In this project I evaluate whether nesting
associations of two species influence nest defence intensity. A model
system in the study are the Barred Warbler and the Red–backed Shrike.
Barred Warblers nesting within shrike breeding territories strongly
defended their nests. Shrikes not nesting together with warblers were
significantly more aggressive than those breeding in the protective
nesting association. This study suggests that positive interactions
within the heterospecific network of relations in ecosystems may be one
of the factors responsible for diversifying the intensity of avian nest
defence.



Barred Warbler (by Marek Kołodziejczyk)

Red-backed Shrike (by Marek Kołodziejczyk)
Read the full article, published by Zoological
Studies, here
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