Macquarie University
01whole.pdf (4.41 MB)

Effect of group size and composition on individual behavior, group dynamics and population regulation in the Arabian babbler (Turdoides squamiceps)

Download (4.41 MB)
posted on 2022-03-28, 09:38 authored by Oded Keynan
Cooperative breeding is a social system in which individuals help care for young that are not their own. Considerable research has found that cooperation can result in a number of benefits for group members, including enhanced reproductive success and greater longevity. These benefits lead to the possibility that the social structure of the group an individual comes from may have important long-term fitness consequences. However, little is known about the relative importance of social and environmental factors on individual fitness traits and group dynamics in the long-term in cooperatively breeding species. Thus, long-term studies on how social and environmental factors influence the costs and benefits of cooperative behaviour are of extreme importance. In this thesis I explore how social and environmental factors influences the individual, the group and the population in cooperatively breeding Arabian babblers (Turdoides squamiceps). I did that by (a) experimentally investigating the factors influencing individual foraging strategies and innovative behaviour, (b) analysing a long-term database to study the effect of social and environmental factors on individual fitness traits and group dynamics, and (c) determining whether inverse density dependence (Allee effects) occurs at both the group and population level. I found that dominant and subordinate individuals differ in both foraging and cognitive strategies, and that novel foraging skills may be socially transmitted, outlining an important benefit of group-living. I also found that group size and reproductive competition significantly affected reproductive success and group dynamics, suggesting that social factors are important influences on both individual fitness and group demography. Finally, I found the existence of both group and demographic Allee effects in the study population, which represents an important consideration for the management and protection of cooperatively breeding species. These findings provides novel approaches that may benefit further studies on individual fitness and group dynamics in cooperative breeders.


Table of Contents

1. Introduction -- 2. General methods -- 3. Social foraging strategies and acquisition of novel foraging skills in cooperatively-breeding Arabian babblers -- 4. Task-dependent differences in innovation abilities by subordinate and dominant wild Arabian babblers -- 5. Causes of variation in dominance acquisition, tenure, and lifetime reproductive success in a cooperatively breeding bird -- 6. Long-term analysis of social and environmental influences on group dynamics in a cooperative breeder -- 7. Long-term population analysis reveals the presence of group and demographic Allee effects on a cooperatively breeding bird species -- 8. General discussion -- References -- Appendices.


Includes bibliographical references Thesis by publication. "A dissertation submitted to Macquarie University in application for the degree of Doctor of Philosophy November 2014".

Awarding Institution

Macquarie University

Degree Type

Thesis PhD


PhD, Macquarie University, Faculty of Science, Department of Biological Sciences

Department, Centre or School

Department of Biological Sciences

Year of Award


Principal Supervisor

Simon C Griffith

Additional Supervisor 1

Amanda Ridley

Additional Supervisor 2

Arnon Lotem


Copyright Oded Keynan 2015. Copyright disclaimer:




1 online resource (215 pages) colour illustrations, colour map

Former Identifiers