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Digital archive of theses discussed at the University of Pisa

 

Thesis etd-01072023-172302


Thesis type
Tesi di laurea magistrale
Author
BALDESCHI, BENEDETTA
URN
etd-01072023-172302
Thesis title
Red fox dietary adaptation to wildfires: prey selection in a Mediterranean mountainous area
Department
BIOLOGIA
Course of study
CONSERVAZIONE ED EVOLUZIONE
Supervisors
relatore Prof. Massolo, Alessandro
tutor Dott. Tomassini, Orlando
Keywords
  • fires
  • Mediterranean
  • prey selection
  • red fox
  • small mammals
Graduation session start date
24/01/2023
Availability
Withheld
Release date
24/01/2093
Summary
Fires are a worldwide disturbing phenomenon that affects global ecosystems and ecological processes. In Mediterranean biomes, fires are a common disturbance, however, even though many species are recurrent in fire-prone environment, post-fire animal dynamics are still inadequately investigated. The alteration of food resources is a major effect of fire, which occurs manly through modification of vegetation structure, and the subsequent secondary succession phenomenon. During this process, both prey and predators play important roles for the recovery of the ecosystem.
Among mesocarnivores, Red fox is a generalist medium-size predator which is known to have overall a positive post-fire response, probably due to an increased availability of prey or facility to hunt.
In my thesis, first a literature review was conducted on the current knowledge about post-fire feeding habits and selection shifts in animal communities; then, to explore post-fire dietary shifts, a study on fox prey selection, with a focus on small mammal prey, was carried out. The literature review was carried out considering the general framework of animal communities, to acquire useful information about post-fire predator-prey interactions, valuable also to understand Red fox post-fire feeding choices.
Following the PRISMA statement a total of 26 articles were included. Geographical location, relative studied species and trophic level occupied where recorded and used for a qualitative description. The fox diet selection study took place during the 2021 warm season on the Monte Pisano mountain system, a typical Mediterranean area, three years after a fire.
The availability of small mammals was assessed using hair-trapping procedure, whereas Red fox diet was established through scats collection and morphological analysis. During the preliminary steps of data analysis, Red fox diet was described and compared with other studies conducted in similar undisturbed Mediterranean areas. Subsequently, the Manly selectivity index was adopted to evaluate the existence of selection. Finally, single prey preference tests were accomplished for all small mammals, and significance among differences between selectivity indices were performed to reveal the eventual direction of selection.
As for the review, I found that the great majority of the studies were conducted on North America and Australia, whereas the most investigated ecological functional group was the one of prey. Moreover, I found geographical gaps in post-fire feeding studies, suggesting that important information may be missing for the Mediterranean basin. Moreover, mainly herbivore species were considered, whereas little has been reported about many other prey species which are fundamental during the ecosystem regeneration. Finally, a paucity of information was predominant for carnivore species, which instead play strong effects on trophic webs through their top-down effects.
The prey selection analysis showed the existence of selection among small mammals. A negative selection emerged for Mus sp., Microtus sp. and Crocidura sp., while Glis sp. showed a tendency to significance. Apodemus sp. was used in accordance to its availability, as for Sciurus sp. and Eliomys sp.. Red fox showed a diet in agreement with other Mediterranean areas where fruits and seeds, invertebrates and small mammals were the most important categories consumed.
My results confirmed the known high feeding plasticity of this mesocarnivore which can exploit different prey according to their availability, but also to their catchability.
Future studies will be necessary to further investigate Red fox and other carnivores’ food shifts after fire disturbance, including different seasons and other successional stages.
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