Red Fox

The discovery in 2008, during an archaeological survey carried out on the Digges Islands (southern shores of Hudson Strait, Nunavut), of a fox den (Vulpes vulpes) with associated bones allow us to better understand the feeding habits of the red fox in an arctic periglacial context. The bones, essentially representing diverse bird species, were collected near the entrance and exit points of the still active den. Bird species include the Canada goose (Branta canadensis), the snow goose (Chen caerulescens) and the murres (Uria lomvia). The majority of these birds was caught during the month of July 2008 by the foxes, especially during their summer migration phase. The den being still active, fox cubs were present during our passage. It is planned to make a brief return over the coming years to see if more bones will have accumulated since our
last visit.

The year-round food habits of lynx were studied using radio-telemetry and snow-tracking in the boreal forest of southeastern Norway. The main objectives of the study were to clarify the importance of domestic sheep and small prey species in the diet of lynx in an area with a very low density of roe deer. During the period 1995–1999, we found 193 scats and 358 kills made by lynx. Our results indicate that roe deer were the most common prey species (contributing to 83 and 34% of the biomass consumed in winter and summer, respectively), although a wide range of other species were also found, including mountain hares, tetranoids, red foxes, domestic sheep, wild reindeer, and even moose. Most of the diet was obtained by predation, although we did document several cases of scavenging. Roe deer were more important in the diet in winter than in summer, perhaps because they were easier to locate in winter as they clustered around feeding sites. In summer, domestic sheep and small prey increased in importance. Despite the very low density of roe deer in this study area, lynx seemed to still specialise on them, although domestic sheep did constitute a significant amount to their diet, especially for males and yearlings. However, the contribution of sheep to summer diet was far from that expected if their relative density was considered.

The costs of dispersal are an important factor promoting natal philopatry, thereby encouraging the formation of social groups. The red fox, Vulpes vulpes, exhibits a highly flexible social system and one that is thought to represent a possible stage in the evolution of more complex patterns of group-living. Although the potential benefits accruing to philopatric offspring have previously been studied in this species, the potential costs of dispersal have received less attention. We contrasted survival rates, nutritional status, ...

Decline of red fox (Vulpes vulpes) populations in Illinois has been attributed to altered geographic landscapes and the eastward expansion of the coyote. To investigate effects of habitat use and competition with coyotes on diets of foxes in intensively farmed landscapes of Illinois, we analyzed carbon and nitrogen isotope ratios (δ13C and δ15N) of foxes, coyotes (Canis latrans), and other local species. Foxes were categorized as rural (agricultural habitat, coyotes present), urban (urban habitat, coyotes absent), or from an agricultural research facility at the University of Illinois (South Farms, agricultural habitat, coyotes absent). Rural foxes had higher fur isotopic values (δ13C and δ15N) than rural coyotes, indicating that coyotes caused foxes to consume prey items from higher trophic levels and eat more C4 plants. Urban foxes had lower isotopic values (δ13C and δ15N) than South Farms foxes, suggesting that habitat use partly determined fox diets; foxes in urbanized habitats ...

Context. Introduced mammalian predators have been responsible for population declines in native prey species around the world. Many conservation programs rely on control or eradication of introduced mammalian predators, but the impact of environmental variation on the efficacy of this approach is rarely documented.
Aims. The present paper describes (1) the impact of introduced European foxes (Vulpes vulpes) on breeding Australian pelicans (Pelecanus conspicillatus) in South Australia and (2) the responses of both species to a fox-eradication program using a before-after-impact framework.
Methods. The impact of foxes on breeding Australian pelicans was studied on a near-shore island. An index of fox abundance and direct measurements of breeding pelicans and mortality of pelican eggs and young were compared before foxes were established on the island, while foxes were resident and during a fox-eradication program. A path analysis was used to explore the causal relationships between fox abundance and other potential covariates (e.g. rainfall) on breeding
pelicans.
Key results. Before foxes were established on the island, the number of breeding pelicans grew and egg mortality was low. While foxes were resident, the number of breeding pelicans fell and egg mortality rose. This was followed by an increase in the number of breeding pelicans and a decrease in egg mortality during a fox-eradication program. While foxes had a clear impact on egg mortality, a period of low rainfall also occurred while foxes were resident. The path analysis showed an
interaction among rainfall, size of the pelican breeding population and the impact of foxes. In drought years, fewer pelicans bred and foxes were a major cause of nest abandonment when they entered pelican breeding colonies to prey on eggs.
Conclusions. These results confirmed that foxes can be an important predator of ground-nesting, colonial waterbirds, and showed that the impact of foxes may be higher in drought years when prey populations are low.
Implications. The present study suggests that an increase in the incidence of droughts as a result of climate change may increase the impact of introduced predators on drought-sensitive waterbirds and raises the possibility of focusing predator-control efforts during droughts, as periods of particular risk to colony-breeding waterbirds.