Overlap of habitat use by foxes, other introduced predators and their prey

Grimshaw, Hannah (2022) Overlap of habitat use by foxes, other introduced predators and their prey. Honours thesis, University of Southern Queensland. (Unpublished)

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Australia has experienced the highest rate of mammalian extinction and loss of biodiversity in the world. A primary cause of diversity loss has been the introduction of mammalian predators, such as foxes (Vulpes vulpes). Introduced predators predate on native species, spread novel diseases, and impose both direct and indirect competition. Foxes also negatively impact the agricultural industry through similar means. Foxes have thrived in Australia as they are particularly adaptable and can survive within most habitat types, except for extremely arid or tropical landscapes. Current control methods used to reduce and maintain populations are unable to eradicate foxes from large areas or prevent immigration and reimmigration following a reduction in population. An increase in anthropogenic landscapes have increased the expansion of transportation networks, which impose multiple impacts to natural ecosystems and wildlife. Wildlife crossings are commonly used to alleviate these risks, although it can be difficult to determine the most effective structures to benefit the maximum number of species. Wildlife crossing structures (WCS) are used to alleviate road induced impacts; although it may be difficult to determine an effective structure to be applied universally. Variations in ecosystems and specific species preferences prevents use of a generalised wildlife crossing structure. While foxes are primarily nocturnal, they willingly alter daily activity patterns to increase access to prey and avoid risk (e.g. interaction with their own predators). The influence of one species’ behaviour on another is known as interspecific interaction. Predators aim to align their daily activity with that of prey species to improve hunting efforts. Prey species attempt to minimise overlap with predators to avoid predation. Mesopredators, such as foxes, act as both predators and prey as they are dominated by top-predator species but require access to prey. Aims of this project were to determine if foxes avoid top-predators, if foxes overlap temporal behaviour with prey species, if foxes prefer natural habitat or modified landscapes, and if foxes change temporal activity seasonally. Temporal overlap between foxes was compared between two habitat types (agricultural landscapes and roadside WCS), as well as other species present at each study. This project will fill current gaps in understanding how foxes interact with other species within different landscapes during the study period. Insight is provided into why fox activity either corresponds or differs from the daily activity of other introduced predators and native and introduced prey species. This study was conducted across two different studies, with different methodologies. It would be beneficial to conduct this project again using the same methodologies across a period of 12 months. A replication of this project over at least 12 months would provide a better representation all species’ activity in each environmental season. It was hypothesised that foxes; (1) would utilise human-modified landscapes more frequently than natural habitats, (3) increase temporal activity during winter, (3) activity avoid periods where dog (Canis lupus familiaris) temporal activity increased and increase their daily activity overlap with prey species. Camera traps were set up across two different studies (Hidden Vale Wildlife Centre (HVWC) and Toowoomba Second Range Crossing (TSRC)) to compare the use of habitat by both native and introduced species. The study sites included a nature reserve previously used as a cattle farm (HVWC) and three different WCS integrated into a new traffic highway (TSRC). Recorded camera data was used to compare the temporal overlap of foxes with other introduced predators and prey species. Foxes did show increased activity at TSRC, representing a preference for modified landscapes for movement and increased hunting efficiency. Foxes displayed most activity during winter at the TSRC as a response to reproductive behaviours. Foxes did avoid temporal overlap with wild dogs, indicating avoidance of a top-predator. And finally, fox temporal overlap was high with both native and introduced prey species. It was found that foxes actively used highly, human modified landscapes more frequently compared to an agricultural habitat subjected to habitat restoration. This preference may be due to ease of movement or increased hunting efficiency. Fox behaviour demonstrated seasonality at TSRC. During winter, fox observations were highest, indicating that during winter foxes increased activity and habitat use to participate in reproductive behaviours. There was temporal avoidance of wild dogs, as a top-predator, by foxes. Foxes may avoid wild dogs to prevent aggressive interactions and competition. Foxes and wild dogs may also have different preferences in prey species, and foxes generally have smaller home ranges than wild dogs. This may mitigate any requirement for complete avoidance as foxes do not pose as an absolute threat to wild dogs. Further research at both HVWC and TSRC would benefit the understanding of local pest predators’ behaviour and interactions with each other and both native and introduced prey species. Foxes at both TSRC and HVWC displayed considerable temporal overlap with both native and introduced small mammals. Indicating that foxes will seek to increase periods of activity when prey species are active to improve hunting efforts. There was no significant temporal overlap between foxes and birds which indicates that birds are not a priority to foxes as a prey item. Foxes have been recorded to consume bird species previously, however this may be a result of opportunistic hunting by foxes. Dietary analyses of fox scats and individuals at HVWC and TSRC would provide a thorough understanding of which prey species are most commonly consumed at both sites. Results of this project support the research questions and hypotheses. Increased knowledge of how foxes interact with different landscapes and different species can aid control methods. For example, control methods can be applied to areas which experience higher fox activity to increase the likelihood of baiting or shooting to maximise efficiency. Likewise, if foxes display little preference for certain areas, limited control methods may be applied there to increase the available funding for areas with a higher density. If future research were to be conducted, it would be possible to determine if there is a similar pattern across SEQ, or if local differences vary too much to apply a broad umbrella knowledge. If foxes were to manipulate wildlife crossings for hunting efficiency, localised extinctions may occur, or native species may avoid using crossing structures which increases habitat fragmentation and risk of vehicle collision. If foxes show preference for the use of modified landscapes (such as LTIs and WCS) the practicality and effectiveness of targeted population control in the landscapes can be studied. At WCS, baited feeding stations, intense trapping or shooting efforts may aid population control efforts to remove as many individuals as possible with minimal labour and funding. Non-lethal techniques such as the use of exclusion fencing or guard animals may have potential to create a safe zone for native species to cross, without risk of predation which would otherwise occur by foxes. As wildlife crossings become more prominent, it is important to understand how foxes use these structures to protect native species.

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Item Type: Thesis (Non-Research) (Honours)
Item Status: Live Archive
Faculty/School / Institute/Centre: Historic - Faculty of Health, Engineering and Sciences - School of Sciences (6 Sep 2019 - 31 Dec 2021)
Supervisors: Murray, Peter; Allen, Benjamin; Brady, Megan
Qualification: Bachelor of Science (Honours) (Environment and Sustainability)
Date Deposited: 29 Jun 2023 01:12
Last Modified: 29 Jun 2023 01:12
Uncontrolled Keywords: Bypass; Camera trap; Cat; Culvert; Dog; Fox; Interspecific Intraspecific; Introduced pest; Mesopredator; Overlap; Predator; Prey; Top-predator; Underpass; Viaduct; Wildlife crossing
Fields of Research (2020): 31 BIOLOGICAL SCIENCES > 3103 Ecology > 310301 Behavioural ecology
URI: https://sear.unisq.edu.au/id/eprint/51764

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