Resource use overlap between urban carnivores: Implications for endangered San Joaquin kit foxes (Vulpes macrotis mutica)

Abstract

An urban population of Endangered San Joaquin kit foxes (Vulpes macrotis mutica) has persisted in the city of Bakersfield, (Kern County, California), for several decades. Urban kit foxes may play an important role in future range wide recovery efforts for the species. As such, a comprehensive understanding of the issues that can influence the long-term survival of this population is essential for the development of effective management strategies. Although urban kit foxes have been studied extensively in Bakersfield, interactions between kit foxes and other urban carnivore species are poorly understood. Urban environments can provide a number of opportunities for species to interact in ways not usually observed in natural habitats. Interactions between urban populations of striped skunks (Mephitis mephitis) and kit foxes were investigated at denning locations and cat feeding stations on the California State University-Bakersfield campus, California, USA. A total of 130 individual denning sites were identified, of which 39 (30%) were used by both species. Simultaneous den use by foxes and skunks was recorded on four occasions. Inter and intra-specific aggression was recorded at cat feeding stations on ten separate occasions including three incidences of aggression towards kit foxes by skunks and feral cats (Felis catus). Telemetry data and cat feeding station observations clearly show that interspecific contact does occur in urban environments.

The good, the bad, and the ugly: space use and intraguild interactions among three opportunistic predators—cat (Felis catus), dog (Canis lupus familiaris), and red fox (Vulpes vulpes)—under human pressure

“…Surprisingly, although the domestic dog is the most common predator in the world, few studies have addressed its ecological effects on sympatric native predators (Vanak and Gompper 2009b). Studies of the interactions between wild and domestic predators have been conducted in urban habitats (e.g., Harris 1981;George and Crooks 2006;Baker et al 2010;Harrison et al 2011). Studies have also been conducted in Australia, where possible interactions between three alien species (dogs, cats, and red foxes) are of crucial conservational importance (Dickman 1996;Robley et al 2004;Mitchell and Banks 2005;Letnic and Dworjanyn 2011).…”

Management and Conservation of San Joaquin Kit Foxes in Urban Environments

“…Because of space limitations in urban environments, these species all occur in close proximity. For example, all of the species have been observed, sometimes concurrently, at or near feeding stations established for feral cats (Harrison et al 2011). Also, as mentioned previously, several of the species have been observed using kit fox dens.…”

“…The other species probably do not engage in interference competition with kit foxes, but do use kit fox dens and likely overlap in diet. Feral cats and striped skunks have been observed using kit fox dens (Cypher 2010, Harrison et al 2011.…”

“…Also, as mentioned previously, several of the species have been observed using kit fox dens. Indeed, radio-collared striped skunks and kit foxes were detected together in dens on 4 occasions (Harrison et al 2011). Thus, the potential for the transmission of diseases to kit foxes is high.…”

Infectious Disease and Contaminants in Urban Wildlife: Unseen and Often Overlooked Threats

“…The CDV exposure was thought to have come from stowaway raccoons from boats or from domestic dogs. Similarly, the endangered San Joaquin kit fox ( Vulpes macrotis mutica) in urban areas in the Central Valley of California faces exposure to rabies and other felid diseases through regular interactions at den sites and cat-feeding stations (Harrison et al 2011). Intense habitat fragmentation of urban landscapes means small populations of common species are also subject to local extirpation from factors such as disease.…”