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Digital archive of theses discussed at the University of Pisa

 

Thesis etd-05262024-191545


Thesis type
Tesi di laurea magistrale
Author
MARCUCCI, MARTA
URN
etd-05262024-191545
Thesis title
Enemies Without Benefits: The Sad Story Of Small Cats In The Carnivore Guild. Species strategies for the coexistence with sympatric carnivores.
Department
BIOLOGIA
Course of study
CONSERVAZIONE ED EVOLUZIONE
Supervisors
relatore Prof. Massolo, Alessandro
relatore Dott. Petroni, Luca
Keywords
  • carnivores
  • intraguild interactions
  • mesocarnivores
  • niche
  • overlap
  • small cats
  • spatial
  • temporal
  • trophic
Graduation session start date
10/06/2024
Availability
Withheld
Release date
10/06/2027
Summary
Small cats are often part of complex ecological ecosystems where they coexist and interact with several other carnivores in such carnivore guilds; nonetheless, while larger predators have been object of much research, there is a lack of studies on these small carnivores. Finally, despite the relevance of small cats in conservation, not much is known on how they survive under the pressure of complex intraguild interactions which are often affected by human disturbance.
This thesis aimed to summarise what is known on small cats’ strategies adopted to survive within their carnivore guilds through a systematic review on the existing literature on carnivore guilds including small cats, following the PRISMA 2020 statement. This shed the light on the state of art on the topic, revelling what type of intraguild interactions experienced by small cats were reported in literature, and it allowed to highlight knowledge gaps in terms of neglected species, different geographic distribution of studies, types of interactions reported, and the quantitative assessment of the outcomes of such interactions. Therefore, papers resulted from the systematic review were screened in more detail to be included in a quantitative meta-analysis with the purpose of assessing if the degree of niche overlap was affected by the difference in body mass of the involved species. Such dyads were characterised by a small wild cat interacting with a larger or of comparable size competitor. Temporal, spatial, and trophic niches were modelled separately through binomial generalized linear mixed-effect models; the dependant variables had three categorical classes (“low”, “medium” and “high” degree of temporal or spatial overlap) or two (“low” and “high” degree of trophic overlap). Low niche overlap was supposed to be a proxy for high level of species competition as the result of avoidance.
A positive association was found between the degree of temporal overlap and the mass ratio of felid-felid dyads. It resulted that dyads made by similar species as felid-felid, and particularly those with comparable body mass, had higher probability of low temporal overlap compared to dyads including a non-felid, or those with felids of different body sizes. Despite the small sample sizes of trophic and spatial overlap data did not allow to include all the predictors of interest in the models, a negative association was found between the degree of trophic overlap and the mass ratio of felids. Felids with similar body mass had an increased probability of having high trophic overlap. Instead, spatial overlap models did not result in significant effects of the included predictors.
The alarming number of wild cat species omitted in the studies found, along with the importance of the temporal axis for the coexistence within their guilds, and the severe lack of data found for spatial and trophic axes require further research efforts that are urgently needed. Conclusions and recommendations are drawn up to help understand which gaps should be covered with priority by future research, and which data should be collected to improve our knowledge of their intraguild survival strategies, so to implement proper conservation actions, particularly where the carnivore guilds are impacted by humans.
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