An attempt to evidence post-fire adaptation of red fox diet in a Mediterranean area

Abstract

Although fires are common in Mediterranean ecosystems, there are substantial knowledge gaps regarding post-fire shifts in animal diets, especially for carnivores. Red fox Vulpes vulpes is a generalist medium-size carnivore known to have a positive post-fire response, probably due to increased prey availability or facility to hunt. As small mammals are often one of its primary food categories, and early successional visitors of post-fire habitats, we hypothesize a change in red fox diet composition in the warm season after a fire. Hair trapping and scat collection were used to investigate selection of small mammals in a typical Mediterranean region, 3 years after a fire. The diet composition of the fox was compared with that of the fox in the same area in 1992, and with other undisturbed Mediterranean areas. Diet selection was evaluated through the Forage ratio and single resource preference tests. Red fox diet was consistent with other Mediterranean areas, with fruits and seeds, invertebrates, and small mammals being the most consumed categories. However, small mammals were consumed significantly less than in 1992, while fruits and seeds significantly more. Resource selection analysis indicated avoidance for some ground-foraging small mammals, including Crocidura spp. house mouse Mus domesticus and voles, whereas Apodemus spp. were selected. Arboreal-foraging species, e.g. red squirrel Sciurus vulgaris and garden dormouse Eliomys quercinus were used in proportion to their availability. We concluded that this mesocarnivore had high feeding plasticity and exploited various resources according to their availability and catchability. Future studies are needed to further investigate red fox and other carnivores’ food shifts after fire disturbance, including various seasons, other successional stages and competition within predator guilds.

Highlights

Fox mostly consumed fruits

post-fire avoidance on 3 ground-foraging species

Fox feeding follows both resource availability and catchability

KEY WORDS:

• availability
• fires
• food habits
• mammals
• prey
• scats
• selection

Acknowledgments

The authors would like to thank the University of Pisa Working group (Tavolo Tecnico) for the Monte Pisano fires, which is dedicated to support the local community to study the effects of fires and to promote restoration of burnt areas. Moreover, we would like to thank Regione Toscana, the University of Pisa and the Department of Biology for funding the PhD Scholarship for Orlando Tomassini following the recommendation provided by the Tavolo Tecnico.

Our thanks go to the University of Pisa Museum of Natural History and Simone Farina for providing us with hair samples to use as references. We extend our appreciation to Paolo Cavallini for giving us access to his PhD Thesis, and to Marco Lucchesi for his assistance in identifying red fox faecal pellets, and to John Kastelic for his valuable assistance in refining the written content. Additionally, we are grateful to Andrea Favilla and Andrea Pardini for their help with data collection in the field, and Anna Aghemo for her contribution both in the field and in the laboratory. Lastly, we are indebted to three anonymous reviewers whose comments helped to improve the quality of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

AUTHOR CONTRIBUTION

B. Baldeschi and O. Tomassini equally contributed to the paper.

B. Baldeschi contributed to the fieldwork and laboratory analyses, conducted statistical analyses, and wrote the manuscript. O. Tomassini developed the sampling design, conducted the field work and laboratory analyses, and helped in the writing of the manuscript. A. Massolo supervised the overall study, and edited the manuscript. D. Giunchi, G. Petroni and G. Bedini supported the study, and edited the manuscript. All the authors approved the final version of the manuscript.

SUPPLEMENTAL DATA

Supplemental data for this article can be accessed at https://doi.org/10.1080/03949370.2023.2298482

Additional information

Funding

This work was supported by the Regione Toscana through the “Monito-rare” project, and by the University of Pisa Working group (Tavolo Tecnico) established to support studies to understand fire effects and dynamics in the Monte Pisano area after the fire of 2018.