Multi-generational fidelity, ecological and social determinants of roosting in a cooperatively breeding bird (Argya squamiceps)

TL;DR

This study examines roosting behavior in Arabian babblers over 15 years, revealing long-term site fidelity and social patterns.

Contribution

The study documents the longest roosting site fidelity in cooperatively breeding birds and mammals.

Findings

Arabian babbler groups show strong fidelity to 2.4 main roosting sites within their territory.

Roosting sites are chosen in inner territory areas with dense canopies, regardless of territorial conflicts.

Groups maintain roosting site fidelity across multiple generations and over 15 years.

Abstract

Sleep is an important but overlooked component of animal behaviour, especially its social and conservation facets. Here, we use 15 years of data to comprehensively describe the roosting behaviour of cooperatively breeding birds and test hypotheses about its ecological and social determinants. We show that wild Arabian babbler groups in the Arava Desert of Israel preferred roosting in live plants with dense canopies (mostly Acacia tree spp. and reed clusters). Roosting sites were located in the inner areas of territories regardless of territorial conflicts. Groups almost always roosted in intimate huddles but tended to separate into sub-groups that roost in nearby trees as group size increased. Despite the abundance of suitable sites for roosting, each group only used an average of 2.4 main roosting sites within its territory. Social groups thus exhibited strong, non-random fidelity to specific roosting sites that extended over ≥4 group generations and ≥15 years. To the best of our knowledge, this is the longest roosting site fidelity shown for cooperatively breeding birds and mammals. This study stresses the importance of conserving roosting sites of species with strong site fidelity and lays the foundations for advanced sleep research in a highly cooperative species.

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