Diet of the introduced red fox Vulpes vulpes in Australia: analysis of temporal and spatial patterns

Abstract

The red fox Vulpes vulpes is one of the world’s most widespread carnivores. A key to its success has been its broad, opportunistic diet. The fox was introduced to Australia about 150 years ago, and within 30 years of its introduction was already recognised as a threat to livestock and native wildlife. We reviewed 85 fox diet studies (totalling 31693 samples) from throughout the species’ geographic range within Australia. Mammals were a major component of fox diet, being present in 70 ± 19% of samples across n = 160 locations. Invertebrates (38 ± 26% n = 130) and plant material (26 ± 25% n = 123) were also both staple foods and often the dominant food category recorded. Birds (13 ± 11% n = 137) and reptiles (10 ± 15% n = 132) were also commonly reported, while frogs were scarcely represented (1.6 ± 3.6% n = 111) in fox diet studies. Biogeographical differences reveal factors that likely determine prey availability. Diet composition varied with ecosystem, level of vegetation clearing and condition, and climate zone. Sample type (i.e. stomach versus scat samples) also significantly influenced reporting of diet composition. Livestock and frogs were underrepresented in records based on analysis of scats, whereas small mammals (native rodents, dasyurid marsupials, and bats) were more likely to be recorded in studies of scats than in studies of stomach contents. Diet varied seasonally, reflecting activity patterns of prey species and food availability. This synthesis also captures temporal shifts in fox diet over 70 years (1951–2020), as foxes have switched to consuming more native species in the wake of successful broadscale biological control of the invasive European rabbit Oryctolagus cuniculus. Diet analyses, such as those summarised in this review, capture the evidence required to motivate for greater control of foxes in Australia. This synthesis also highlights the importance of integrated pest species management to meet biodiversity conservation outcomes.

Introduced red foxes (

“…In addition, some fox populations may be enhanced by mesopredator release due to suppression of Australia's apex terrestrial predators, dingoes and other wild dogs (Wallach et al 2010;Letnic et al 2011; though see Allen et al 2013). Furthermore, foxes may benefit from anthropogenic food subsidies (Oro et al 2013), which they widely exploit (Fleming et al 2021). Consequently, the pressure of fox predation on turtle nests is likely to be spatially variable and intense in some regions.…”

Red foxes in Japan show adaptability in prey resource according to geography and season: A meta‐analysis

“…This suggests that foxes in Japan show dietary plasticity by switching their main prey from mammals to alternative foods when prey availability is low ("optimal foraging theory"; Charnov, 1976). This flexibility is well-documented in fox populations in Europe (Díaz-Ruiz et al, 2013;Soe et al, 2017) and Australia (Fleming et al, 2021), and is also a common phenomenon in other mesocarnivore species such as martens Martes spp. (Hisano, Newman, et al, 2019;Zhou, Newman, Xu, et al, 2011), wildcats Felis silvestris (Lozano et al, 2006), leopard cats Prionailurus bengalensis (Hisano & Newman, 2020), and golden jackals Canis aureus (Tsunoda & Saito, 2020).…”

“…Population density can be a good indicator of interactions with human activities and degradation of natural habitats (Lamb et al, 2020) as it generally correlates with the volume of traffic and the percentage of building landscapes (Bateman & Fleming, 2012; McKinney, 2002; Šálek et al, 2015). Therefore, it has been widely used as a collective measure of anthropogenic impacts on diets of terrestrial predators (Bateman & Fleming, 2012; Cavallini & Volpi, 1996; Fleming et al, 2021; Hisano et al, 2016; Janžekovič & Klenovšek, 2020).…”

“…Previous studies suggest that at least 20–50 samples should be analyzed when comparing between ecological groups (e.g., site, season, species, and sex) (Hass, 2009; Hisano et al, 2016; Mata et al, 2019; Whitaker et al, 2009). It is common, however, for dietary meta‐analyses to include seasonal observations when s ≥ 20 (Doherty et al, 2015; Doherty et al, 2019; Hisano & Newman, 2020), ≥15 (Díaz‐Ruiz et al, 2013; Hisano, Newman, et al, 2019; Soe et al, 2017; Tsunoda & Saito, 2020), or even ≥10 (Fleming et al, 2021) since the main objective of systematic studies is to generalize a pattern with a large number of observations, rather than with pairwise comparisons of diet between ecological groups. The results from this alternative analysis were qualitatively similar to those using the full dataset (Figures S1 and S2); therefore, we focused on reporting results from the original dataset.…”

“…The red fox is a flexible generalist, and capable of feeding on a variety of foods in different combinations and ratios. Previous large-scale meta-analyses of red fox diets in Europe and Australia have shown that this species demonstrates a large variation in trophic niches shaped by geo-climatic and human influences (Díaz-Ruiz et al, 2013;Fleming et al, 2021;Soe et al, 2017). There is a lack, however, of systematic dietary information for the red fox in Asia (Middleton et al, 2021;Tsukada, 2005).…”