Author: Taylor Headland
Headland, Taylor, 2025 Urban tolerance of raptors at the global, regional, and local level, Flinders University, College of Science and Engineering
Terms of Use: This electronic version is (or will be) made publicly available by Flinders University in accordance with its open access policy for student theses. Copyright in this thesis remains with the author. You may use this material for uses permitted under the Copyright Act 1968. If you are the owner of any included third party copyright material and/or you believe that any material has been made available without permission of the copyright owner please contact copyright@flinders.edu.au with the details.
Urbanisation is a key driver of biodiversity loss worldwide, causing irreversible ecosystem changes at the global, regional, and local level. While the impacts of urbanisation on wildlife, particularly in an urban setting, have been studied extensively for some taxa, there is a lack of understanding of how raptor species may differ in their ecology from urban to rural landscapes, especially in the Southern Hemisphere. This study investigates the factors that influence urban tolerance of raptors at multiple scales.
Using data sourced from community science projects (also referred to as citizen science) in combination with observational raptor data collected in the field, this study explores how urban tolerance and the use of urban green spaces vary amongst Kestrel species across the globe (Chapter 1), which traits influence urban tolerance in Australian raptor species (Chapter 2), and how the richness and diversity of Australian raptors vary along an urban-rural gradient (chapter 3). At the global level, urbanisation was the most important predictor of Kestrel occurrence and count for all three species modelled, which were all urban avoidant. Urban green space, particularly grassland, shrubland, and cropland, were important predictors of Kestrel occupancy in cities. At the regional level, out of the 24 Australian raptor species analysed, 13 species were urban tolerant, while 11 species were urban avoidant. Many of the urban tolerant species were bird specialist feeders. Smaller Australian raptor species were found to be more tolerant of urban areas than larger raptor species. At the local level, species richness analyses revealed that a greater number of species were observed in towns compared to cities, and a greater number of individual birds were observed in the rural zone compared to the urban zone of towns. Species diversity analyses showed no significant difference in the diversity of birds observed across cities and towns and their urban zones. Trait-based analysis revealed that body mass, diet breadth and habitat breadth were not significant predictors of where birds were observed across locality types and zones.
The use of large-scale datasets and complex statistical analysis has given insight into the urban tolerance of raptors in the Southern Hemisphere, which has traditionally been poorly understood. This study bolsters our knowledge of how raptors respond to urbanisation as well as the underlying traits associated with urban tolerance across the urban-rural interface. It also draws attention to the importance of urban green space in cities and their benefit to urban-adapted wildlife in the form of foraging and breeding grounds. The distribution of raptors in the Southern Hemisphere is being impacted by urbanisation across large spatial scales, and the results of this study highlight the need to conserve suitable natural habitats that support raptor survival beyond urban areas.
Keywords: raptors, birds of prey, urban tolerance, citizen science, urban green space
Subject: Biology thesis
Thesis type: Doctor of Philosophy
Completed: 2025
School: College of Science and Engineering
Supervisor: Diane Colombelli-Négrel