Behind enemy lines: investigating suppression & coexistence between sympatric carnivores in Plitvice Lakes, Croatia

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Documents

  • Peter Haswell

    Research areas

  • Doctor of Philosophy (PhD), Mesopredator, Risk, Giving-up density, Occupancy Analysis, Activity patterns, Interspecific competition, Intraguild, Apex predator, Large carnivore, Human disturbance, National Park, Croatia, Wolf, Lynx, Fox, PhD

Abstract

This thesis fills knowledge gaps regarding spatio-temporal interactions between sympatric carnivores, mesopredator risk mitigation behaviour, and thus, the mechanisms that enable coexistence. In the Anthropocene biodiversity crisis, discerning how and when diversity is maintained is critical. Employing a robust multi-method approach, a model study system was used to examine the top-down effects of wolves, Canis lupus and Eurasian lynx, Lynx lynx, upon red fox, Vulpes vulpes in Plitvice Lakes National Park, Croatia.
Chapter Two utilises novel foraging experiments, combining camera traps with the giving-up density (GUD) framework. Foxes responded to wolf urine by taking less food, spending less time at patches, leaving at higher quitting harvest rates, and adjusting their behaviour when at patches, spending less time foraging and more time being vigilant and sniffing the ground. Chapter Three examines spatial relationships using occupancy modelling. Foxes were not spatially excluded by large carnivores, but were in fact attracted to them (or at least the same conditions) and more detectable in their presence. The positive association was most strongly related to lynx, however, conversely, foxes responded elusively towards human activity. Chapter Four examines temporal relationships using kernel density estimates, circular statistics and nocturnality risk ratios. Fox activity overlapped with other carnivores but avoided peak activity periods, having significantly different record distributions. Foxes were more nocturnal in higher intensity large carnivore presence, seemingly using the cover of darkness to remain safe. High human activity however mediated this interaction, decreasing its strength.
Subtle temporal avoidance and fine-scale spatio-temporal risk mitigation strategies can enable mesopredator access to resources and predator coexistence in the presence of intraguild aggression. Where food subsidies are absent, humans may increase mesopredator elusiveness but may also offer some level of temporal shielding from large carnivores. Protected area management should consider ecological baselines and the effects of human disturbance.

Details

Original languageEnglish
Awarding Institution
  • Bangor University
Supervisors/Advisors
Award date7 May 2019

Research outputs (4)

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