Thirty-eight per cent of deaths of red foxes in European cities are due to animals being destroyed. Similar figures exist for urban areas in the US (35%), but in rural US, hunting is a minor cause of death in foxes (9%), where predation (38%) and death on roads (40%) are the major causes of mortality. Pollutants (e.g. motor oil and antifreeze) and poisons (particularly anticoagulant

rodenticides, directly poisoning the animal or where Selleckchem Fluorouracil the carnivore takes poisoned rodents) are likely to be a significant cause of mortality in urban carnivores. However, our literature review indicated that toxicity is listed as a cause of death for only a few urban and rural coyotes (Riley et al., 2003; Van Deelen & Gosselink, 2006) (Fig. 2) and for kit foxes (Cypher, 2010). The lack of reports may be related to difficulty in ascertaining poisoning as a cause of death, particularly when carcasses are located some time after death. Organochlorines (Dip et al., 2003) and lead (Dip et al., 2001) are found in higher concentrations in urban than rural red foxes in Zürich. Organochlorine levels increase in adult male foxes but not vixens, which appear see more to pass the compounds to their offspring through lactation. Protection from predators is likely to play an important role in selection of urban habitats. Predation

or aggression is responsible for the death of only 10% of urban coyotes compared with 25% for rural populations, where they conflict with wolves (Fig. 2) and it has been suggested that the massive increase in coyote numbers over recent decades is likely due to reduction in

the numbers of grey wolf across North America (Gese & Bekoff, 2004). In turn, coyotes tend to avoid landscapes with extensive human presence, and their conflict with red foxes medchemexpress means that foxes end up being relegated to areas with relatively more intense human activity (e.g. roads, farmsteads) (Gosselink et al., 2007). An estimated 38% of red foxes in rural US die due to predation/aggression, largely due to conflict with coyotes, compared with only 12% in urban US (Gosselink et al., 2007). In the UK, the absence of a natural predator for the fox results in less predation. Nevertheless, even in urban UK (London and Bristol), a high proportion of red foxes die due to wounds incurred during aggression, principally from stray dogs or conspecifics (Harris & Smith, 1987; Soulsbury et al., 2007). Recent control of stray dog numbers, however, has reduced the incidence of aggression as a cause of death (S. Harris, pers. comm. 2010). Disease has been recorded as the major cause of mortality for urban raccoons, accounting for an average of 50% of deaths in urban areas compared with only 19% of rural raccoons (Fig. 2). High levels of sarcoptic mange have been recorded in urban red foxes in Britain, causing population crashes (Baker et al., 2000; Soulsbury et al.