Individual contributions to group behaviour in the cooperatively breeding southern ground-hornbill Bucorvus leadbeateri
type: CreativeWork
description: Cooperative breeding, in which individuals other than breeders contribute to raising offspring, has been the focus of much scientific research over the past decades. Why do some individuals help to raise offspring that are not their own? In birds, cooperative breeding is found mainly in harsh regions with greater environmental variability, such that individuals might do better to help relatives than attempt to breed themselves. However, in some bird families cooperative breeding is instead associated with stable and benign environments, suggesting that species may form cooperative groups for different reasons. Most studies have focused on the benefits that additional group members bring to offspring, by increasing provisioning rates, nestling survival, and overall reproductive output. These benefits have been suggested to mitigate the effects of harsh climatic conditions and to be particularly important in the face of anthropogenic climate change, during which increases in temperature extremes and interannual rainfall variability are expected to push species' tolerance to the limit. However, other advantages of group living have been less often considered; for example, collective territory defence is common in cooperative breeders and ensures exclusive access to crucial resources such as food, nesting sites, and mates. A better understanding of the diverse factors favouring cooperative behaviour can offer insights as to why, and in what environmental conditions, social behaviour has evolved, and whether and how it might help animal populations to cope with environmental change. Therefore, the aims of this thesis were to investigate how individuals within cooperative groups contribute to reproduction and territory defence in an atypical cooperative breeder, the southern ground-hornbill Bucorvus leadbeateri. The large body size and exceptionally long lifespan of ground-hornbills leads to a “slow” life-history strategy, providing a striking contrast to most wellstudied…
abstract: Cooperative breeding, in which individuals other than breeders contribute to raising offspring, has been the focus of much scientific research over the past decades. Why do some individuals help to raise offspring that are not their own? In birds, cooperative breeding is found mainly in harsh regions with greater environmental variability, such that individuals might do better to help relatives than attempt to breed themselves. However, in some bird families cooperative breeding is instead associated with stable and benign environments, suggesting that species may form cooperative groups for different reasons. Most studies have focused on the benefits that additional group members bring to offspring, by increasing provisioning rates, nestling survival, and overall reproductive output. These benefits have been suggested to mitigate the effects of harsh climatic conditions and to be particularly important in the face of anthropogenic climate change, during which increases in temperature extremes and interannual rainfall variability are expected to push species' tolerance to the limit. However, other advantages of group living have been less often considered; for example, collective territory defence is common in cooperative breeders and ensures exclusive access to crucial resources such as food, nesting sites, and mates. A better understanding of the diverse factors favouring cooperative behaviour can offer insights as to why, and in what environmental conditions, social behaviour has evolved, and whether and how it might help animal populations to cope with environmental change. Therefore, the aims of this thesis were to investigate how individuals within cooperative groups contribute to reproduction and territory defence in an atypical cooperative breeder, the southern ground-hornbill Bucorvus leadbeateri. The large body size and exceptionally long lifespan of ground-hornbills leads to a “slow” life-history strategy, providing a striking contrast to most wellstudied…
author: Middleton, Kyle-Mark
keywords: Biological Sciences
date published: 2023
date modified: 2026-07-22T22:23:04Z
provider: University of Cape Town
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Department of Biological Sciences

PropertyValue
property ID: Handle
value: http://hdl.handle.net/11427/38073