Rapid urbanization of red foxes in Estonia: distribution, behaviour, attacks on domestic animals, and health-risks related to zoonotic diseases.

Liivi Plumer,John Davison,Urmas Saarma,Elissa Z Cameron

doi:10.1371/journal.pone.0115124

Abstract

Urban areas are becoming increasingly important for wildlife as diminishing natural habitats no longer represent a suitable environment for many species. Red foxes (Vulpes vulpes) are nowadays common in many cities worldwide, and in recent years they have colonized urban areas in Estonia. We used a public web-based questionnaire approach to evaluate the distribution and behaviour of Estonian urban foxes, to detect related problems and to assess health risks to humans and domestic animals. In total, 1205 responses were collected throughout the country. Foxes have colonized the majority of Estonian towns (33 out of 47) in a relatively short period of time, and have already established breeding dens in several towns. Despite their recent arrival, the behaviour of Estonian urban foxes is similar to that reported in longer-established urban fox populations: they are mostly active during night-time, often visit city centres and some also have dens in such locations. Certain characteristics of urban foxes serve as a basis for conflict with humans: foxes have entered houses and attacked domestic animals, killing cats and poultry. About 8% of reported foxes exhibited symptoms of sarcoptic mange, a disease that also infects domestic animals, especially dogs. The proportion of mange-infected foxes was higher in large urban areas. In addition to mange, a substantial fraction of red foxes in Estonia are known to be infected with the life-threatening tapeworm Echinococcus multilocularis, the causative agent of alveolar echinococcosis. Therefore, urban foxes may represent a source of serious infectious disease for pets and humans.

Highlights

Expanding cities and the general trend towards urbanization are changing natural environments worldwide [1]
The questions sought to find out how many Estonian towns are regularly visited by red foxes, what types of activity the foxes exhibit and whether they are infected with sarcoptic mange
Generalized linear models (GLM; R Core team 2014) with binomial error structures were used to determine whether (i) the proportion of records occurring in winter (December, January and February) was related to the size of the urban area; and (ii) the proportion of records reporting foxes with mange was related to the size of the urban area

Summary

Introduction

Expanding cities and the general trend towards urbanization are changing natural environments worldwide [1]. Even in cities where both population and household numbers have declined, the urban land area has continued to increase due to an increase in the per capita living space [4]. Some organisms are capable of exploiting urban environments better than others, and among mammals, medium body size, social behaviour and behavioural flexibility, including diet, appear to be the main factors associated with successful urbanization. Species such as red fox (Vulpes vulpes), coyote (Canis latrans), raccoon (Procyon lotor) and badger (Meles meles) can be found in cities around the world [7], though smaller mammals including bats, squirrels, hedgehogs, mice and voles, are widespread in urban areas Some urban mammals even establish synurbic populations living at far higher density than nearby rural populations [9], such as red foxes in Switzerland [10]

Methods

Results

Conclusion