Volume contents

Abstract

1. Disease epizootics can significantly influence host population dynamics and the structure and functioning of ecological communities. Sarcoptic mange Sarcoptes scabiei has dramatically reduced red fox populations Vulpes vulpes in several countries, including Britain, although impacts on demographic processes are poorly understood. We review the literature on the impact of mange on red fox populations, assess its current distribution in Britain through a questionnaire survey and present new data on resultant demographic changes in foxes in Bristol, UK. 2. A mange epizootic in Sweden spread across the entire country in < 10 years resulting in a decline in fox density of up to 95%; density remained lowered for 15-20 years. In Spain, mange has been enzootic for > 75 years and is widely distributed; mange presence was negatively correlated with habitat quality. 3. Localized outbreaks have occurred sporadically in Britain during the last 100 years. The most recent large-scale outbreak arose in the 1990s, although mange has been present in south London and surrounding environs since the 1940s. The questionnaire survey indicated that mange was broadly distributed across Britain, but areas of perceived high prevalence (> 50% affected) were mainly in central and southern England. Habitat type did not significantly affect the presence/absence of mange or perceived prevalence rates. Subjective assessments suggested that populations take 15-20 years to recover. 4. Mange appeared in Bristol's foxes in 1994. During the epizootic phase , mange spread through the city at a rate of 0.6-0.9 km/month, with a rise in infection in domestic dogs Canis familiaris c. 1-2 months later. Juvenile and adult fox mortality increased and the proportion of females that reproduced declined but litter size was unaffected. Population density declined by > 95%. 5. In the enzootic phase (1996-present), mange was the most significant mortality factor. Juvenile mortality was significantly higher than in the pre-mange period, and the number of juveniles classified as dispersers declined. Mange infection reduced the reproductive potential of males and females: females with advanced mange did not breed; severely infected males failed to undergo spermatogenesis. In 2004, Bristol fox population density was only 15% of that in 1994.Keywords: Canidae, demographic changes, enzootic, epizootic, red fox, wildlife disease (Funk et al., 2001;Cleaveland et al., 2002;Woodroffe et al., 2004). From an applied perspective, the pre-and post-exposure management of such wildlife diseases can be difficult, controversial and result in significant economic costs (e.g. Flamand et al., 1992; Krebs & the Independent Scientific Review Group, 1997;Aubert, 1999;Donnelly et al., 2003), although, conversely, diseases have also been utilized in the management of problems caused by some feral or wild species (Fenner & Fantini, 1999;Bester et al., 2002). Furthermore, wildlife diseases can also exert significant impacts on host population dynamics (Tompkins et al., 2002) a...

Sarcoptic mange: An emerging panzootic in wildlife

“…In addition, recent studies describe new locations of mange outbreaks. For example, S. scabiei in red foxes is endemic in specific areas in Europe, but recent outbreaks are increasingly being reported in new locations, depicting spatial spread (Soulsbury et al, 2007).…”

Demonstrating frequency-dependent transmission of sarcoptic mange in red foxes

“…Mange epizootics have caused significant declines in red fox Vulpes vulpes populations worldwide [11,15,16]. Previous mange models have only considered direct, density-dependent transmission [12,17] but off-host mite survival [9] and low inter-group contact in foxes [18] suggest that indirect transmission is likely.…”

“…Where possible, initial parameter values were estimated from the literature [11,20,21] (table 1). To determine the performance of the disease transmission models, predicted dynamics were compared with a null model with time-invariant disease prevalence.…”

Sarcoptic mange vulnerability in carnivores of the Białowieża Primeval Forest, Poland: underlying determinant factors

“…The red fox exhibits the widest geographical range of any European carnivore; it can be found in a wide diversity of habitats and often at high densities (Barton´and Zalewski 2007). As the red fox is particularly susceptible to sarcoptic mange (Soulsbury et al 2007), and because mangy animals may visit human settlements in search for easy accessible food sources (Todd et al 1981;Balestrieri et al 2006), they seem to be the main vector of mange transmission between wild and domestic animals. In addition, the red fox appears to be a persistent reservoir of scabies.…”