Content uploaded by Konstantin Börner
Author content
All content in this area was uploaded by Konstantin Börner on Aug 11, 2016
Content may be subject to copyright.
A preview of the PDF is not available
Untersuchungen zur Raumnutzung des Rotfuchses, Vulpes vulpes (L., 1758), in verschieden anthropogen beeinflussten Lebensräumen Berlins und Brandenburgs
Abstract and Figures
Untersuchungen zur Raumnutzung des Rotfuchses, Vulpes vulpes (L., 1758), in verschieden anthropogen beeinflussten Lebensräumen Berlins und Brandenburgs Dissertation zur Erlangung des akademischen Grades doctor rerum naturalium (Dr. rer. nat.) im Fach Biologie eingereicht an der Mathematisch-Naturwissenschaftlichen Fakultät der Humboldt-Universität zu Berlin
Figures - uploaded by Konstantin Börner
Author content
All figure content in this area was uploaded by Konstantin Börner
Content may be subject to copyright.
... In combination with human disturbance, this can influence wildlife distribution patterns in multiple ways, as animals can for instance aggregate in areas with high artificial food concentrations or adjust their home range size and activity patterns to avoid humans (Cavallini, 1996;Smith and Engeman, 2002;Riley et al., 2003;Prange et al., 2004). High resource availability, low hunting pressure and the absence of large predators cause high density of wildlife in urban areas compared to their conspecifics in rural areas (Cavallini, 1996;Contesse et al., 2004;Börner, 2014). Importantly, the close proximity of dense wildlife and domestic animal populations together with humans in urban areas make zoonoses or disease spillovers between host species more likely than in rural areas (Adkins and Stott, 1998;Ditchkoff et al., 2006). ...
... Foxes are well studied urban-dwelling mammals that occur worldwide (Stubbe, 1980;Harris and Smith, 1987;Harris and Trewhella, 1988;Cavallini, 1996;Baker et al., 1998;Contesse et al., 2004;Janko et al., 2012;Börner, 2014). Urban foxes inhabit various urban landscape structures such as home gardens, littlevegetated dense built-up areas or bushy and well-vegetated areas (Harris, 1981;Adkins and Stott, 1998). ...
... Both maps were intersected to obtain a topologically correct map of the study area (Berlin plus 4 km buffer zone from Brandenburg area). Based on this map we reclassified all occurring land use structures (752 categories) into 12 land use structures (see Figure 1) typical for urban areas and meaningful for urban foxes (Harris, 1977;Harris and Rayner, 1986;Janko et al., 2012;Börner, 2014): (1) arable land, (2) inner-city blocks (typical Berlin apartment houses), (3) forest, (4) private green space (gardens, allotments, camping sides), (5) industrial area (warehouses, power plants), (6) public building (schools, train stations), (7) urban green space (parks, botanical gardens), (8) streets, (9) detached houses (villa, leisure residence) (10) water bodies (rivers and lakes), (11) railway tracks (railway sidings and embankments), (12) brownfields covering unbuilt and anthropically unused areas. Georeferenced carcass finding locations indicate the individual's death location; thus, we assigned a wider area (buffer) to each location to capture the possible land cover structures an individual might have used shortly before dying. ...
Urbanization rapidly changes landscape structure worldwide, thereby enlarging the human-wildlife interface. The emerging urban structures should have a key influence on the spread and distribution of wildlife diseases such as canine distemper, by shaping density, distribution and movements of wildlife. However, little is known about the role of urban structures as proxies for disease prevalence. To guide management, especially in densely populated cities, assessing the role of landscape structures in hampering or promoting disease prevalence is thus of paramount importance. Between 2008 and 2013, two epidemic waves of canine distemper hit the urban red fox (Vulpes vulpes) population of Berlin, Germany. The directly transmitted canine distemper virus (CDV) causes a virulent disease infecting a range of mammals with high host mortality, particularly in juveniles. We extracted information about CDV serological state (seropositive or seronegative), sex and age for 778 urban fox carcasses collected by the state laboratory Berlin Brandenburg. To assess the impact of urban landscape structure heterogeneity (e.g., richness) and shares of green and gray infrastructures at different spatial resolutions (areal of 28 ha, 78 ha, 314 ha) on seroprevalence we used Generalized Linear Mixed-Effects Models with binomial distributions. Our results indicated that predictors derived at a 28 ha resolution were most informative for describing landscape structure effects (AUC = 0.92). The probability to be seropositive decreased by 66% (0.6 to 0.2) with an increasing share of gray infrastructure (40 to 80%), suggesting that urbanization might hamper CDV spread in urban areas, owing to a decrease in host density (e.g., less foxes or raccoons) or an absence of wildlife movement corridors in strongly urbanized areas. However, less strongly transformed patches such as close-to-nature areas in direct proximity to water bodies were identified as high risk areas for CDV transmission. Therefore, surveillance and disease control actions targeting urban wildlife or human-wildlife interactions should focus on such areas. The possible underlying mechanisms explaining the prevalence distribution may be increased isolation, the absence of alternative hosts or an abiotic environment, all impairing the ability of CDV to persist without a host.
... Green areas in cities might harbour a high biodiversity[5]and provide natural food items together with street trees or forest patches in cities[20,21]. While studies showing the impact of natural food sources on the diet of urban animals are rare, numerous studies describe the impact of anthropogenic food and garbage[22][23][24][25][26]. Anthropogenic food sources are easily accessible[22,25,27,28]and provide a high amount of energy[29,30]. ...
... In general, seasonal, inter-annual and regional differences in the diet indicate that WB feed different food types according to availability[41]. Since food availability in urban and rural areas differs due to the high availability of anthropogenic food in urban areas[22][23][24][25][26], we expect to find significant differences in the diet of WB from urban areas and those of rural areas. Small-scale influences can be very important. ...
... While the effect of urbanization (increase of human associated landscape variables) has a larger impact for rural WB, regarding the amount of energy, human associated landscape variables play a minor role for the quality of food, as represented by the MOF. A higher food quality in urban areas, as decribed by other studies[29,30]is therefore independent from the landscape per se, but depends on the interaction with humans[22][23][24][25][26]. Deciduous forests had no and coniferous forests only a weak impact on the nutrient composition. ...
Most wildlife species are urban avoiders, but some became urban utilizers and dwellers successfully living in cities. Often, they are assumed to be attracted into urban areas by easily accessible and highly energetic anthropogenic food sources. We macroscopically analysed stomachs of 247 wild boar (Sus scrofa, hereafter WB) from urban areas of Berlin and from the surrounding rural areas. From the stomach contents we determined as predictors of food quality modulus of fineness (MOF,), percentage of acid insoluble ash (AIA) and macronutrients such as amount of energy and percentage of protein, fat, fibre and starch. We run linear mixed models to test: (1) differences in the proportion of landscape variables, (2) differences of nutrients consumed in urban vs. rural WB and (3) the impact of landscape variables on gathered nutrients. We found only few cases of anthropogenic food in the qualitative macroscopic analysis. We categorized the WB into five stomach content categories but found no significant difference in the frequency of those categories between urban and rural WB. The amount of energy was higher in stomachs of urban WB than in rural WB. The analysis of landscape variables revealed that the energy of urban WB increased with increasing percentage of sealing, while an increased human density resulted in poor food quality for urban and rural WB. Although the percentage of protein decreased in areas with a high percentage of coniferous forests, the food quality increased. High percentage of grassland decreased the percentage of consumed fat and starch and increased the percentage of fibre, while a high percentage of agricultural areas increased the percentage of consumed starch. Anthropogenic food such as garbage might serve as fallback food when access to natural resources is limited. We infer that urban WB forage abundant, natural resources in urban areas. Urban WB might use anthropogenic resources (e.g. garbage) if those are easier to exploit and more abundant than natural resources. This study shows that access to natural resources still is mandatory and drives the amount of protein, starch, fat or fibre in wild boar stomachs in urban as well as rural environments.
... While railway-tracks are usually embedded within vegetated verges, motorways are not, and generally, dispersal along such transport infrastructure carries a high mortality risk (200-250 road-killed foxes are found in Berlin each year: Börner, 2014). Yet, what both landscape elements have in common (besides their linearity), is the absence of human activity, in terms of pedestrians and cyclists. ...
Urbanization affects key aspects of wildlife ecology. Dispersal in urban wildlife species may be impacted by geographical barriers but also by a species’ inherent behavioural variability. There are no functional connectivity analyses using continuous individual‐based sampling across an urban‐rural continuum that would allow a thorough assessment of the relative importance of physical and behavioural dispersal barriers. We used 16 microsatellite loci to genotype 374 red foxes (Vulpes vulpes) from the city of Berlin and surrounding rural regions in Brandenburg in order to study genetic structure and dispersal behaviour of a mobile carnivore across the urban‐rural landscape. We assessed functional connectivity by applying an individual‐based landscape genetic optimization procedure. Three commonly used genetic distance measures yielded different model selection results, with only the results of an eigenvector‐based multivariate analysis reasonably explaining genetic differentiation patterns. Genetic clustering methods and landscape resistance modelling supported the presence of an urban population with reduced dispersal across the city border. Artificial structures (railways, motorways) served as main dispersal corridors within the cityscape, yet urban foxes avoided densely built‐up areas. We show that despite their ubiquitous presence in urban areas, their mobility and behavioural plasticity, foxes were affected in their dispersal by anthropogenic presence. Distinguishing between man‐made structures and sites of human activity, rather than between natural and artificial structures, is thus essential for better understanding urban fox dispersal. This differentiation may also help to understand dispersal of other urban wildlife and to predict how behaviour can shape population genetic structure beyond physical barriers.
... The diet of red foxes in urban and periurban areas of Zurich consists of 11% rodents and 10% of them are commensal rodents [42], which could explain the uptake of ARs by urban foxes. In Eastern Germany urban foxes mainly prey on waste, but commensal rodents are taken also and in higher frequencies than in rural areas, where Microtus species are the predominant rodent taxa [37]. Brodifacoum and difenacoum were the main ARs detected in foxes in urban areas, which is similar to results observed in bobcats in California [32] and predatory birds in Spain [33]. ...
Anticoagulant rodenticides (ARs) are commonly used to control rodent infestations for biocidal and plant protection purposes. This can lead to AR exposure of non-target small mammals and their predators, which is known from several regions of the world. However, drivers of exposure variation are usually not known. To identify environmental drivers of AR exposure in non-targets we analyzed 331 liver samples of red foxes (Vulpes vulpes) for residues of eight ARs and used local parameters (percentage of urban area and livestock density) to test for associations to residue occurrence. 59.8% of samples collected across Germany contained at least one rodenticide, in 20.2% of cases at levels at which biological effects are suspected. Second generation anticoagulants (mainly brodifacoum and bromadiolone) occurred more often than first generation anticoagulants. Local livestock density and the percentage of urban area were good indicators for AR residue occurrence. There was a positive association between pooled ARs and brodifacoum occurrence with livestock density as well as of pooled ARs, brodifacoum and difenacoum occurrence with the percentage of urban area on administrative district level. Pig holding drove associations of livestock density to AR residue occurrence in foxes. Therefore, risk mitigation strategies should focus on areas of high pig density and on highly urbanized areas to minimize non-target risk.
In this study, we examine the spatial interrelation between different carnivore species (Carnivora, Mammalia) and ground-nesting birds in a Special Protection Area (SPA) in Brandenburg, Germany. Camera- and live-trapping of carnivores during an 18-month period revealed that the SPA hosts most mesocarnivore species that occur in Germany. Since raccoon (Procyon lotor), red fox (Vulpes vulpes), and domestic cat (Felis silvestris f. catus) showed highest abundance-activity indices, we used GPS telemetry for a detailed analysis of spatial behavior of nine raccoons and five red foxes over a 22-month period. Spatial distribution patterns showed a strong difference between both species: raccoons showed a clear preference for reed swamps and shrub swamps, clustering in high concentrations along the edges of water bodies. Although this behavior is likely due to the high and year-round availability of aquatic food sources, overlap of raccoon core areas with high densities of wetland birds likely results in a high level of sublethal predation effects particularly on waterfowl breeding in reed beds. Red foxes showed much more evenly distributed movement patterns and a high intraspecific variability in habitat preference, revealing a general preference for woodlands and an avoidance of wetlands. Thus, predation pressure by foxes on ground-breeders seems to be lower and focusing on grassland-associated bird species in close proximity to woodlands. Consequently, our study highlights the need for a differentiated view on the predatory potential of particular mesocarnivore species on the endangered bird species in the SPA, leading to future management implications with a focus on swampland habitats.
Background
Red foxes (Vulpes vulpes L.) have become successful inhabitants of urban areas in recent years. However, our knowledge about the occurrence, distribution and association with land uses of these urban foxes is poor, partly because many favoured habitats are on private properties and therefore hardly accessible to scientists. We assumed that citizen science, i.e. the involvement of the public, could enable researchers to bridge this information gap. We analysed 1179 fox sightings in the city of Vienna, Austria reported via citizen science projects to examine relationships between foxes and the surrounding land use classes as well as sociodemographic parameters.
Results
Conditional probabilities of encountering foxes were substantially higher in gardens, areas with a low building density, parks or squares as compared to agricultural areas, industrial areas or forests. Generalized linear model analyses showed that sociodemographic parameters such as education levels, district area, population density and average household income additionally improved the predictability of fox sightings.
Conclusions
Reports of fox sightings by citizen scientists might help to support the establishment of wildlife management in cities. Additionally, these data could be used to address public health issues in relation with red foxes as they can carry zoonoses that are also dangerous to humans.
Worldwide pest rodents on livestock farms are often regulated using anticoagulant rodenticides (ARs). Second generation ARs in particular can cause poisoning in non-target species due to their high toxicity and persistence. However, research on exposure of small mammals is rare. We systematically investigated spatial and temporal exposure patterns of non-target small mammals in a large-scale replicated study. Small mammals were trapped at different distances to bait stations on ten farms before, during and after brodifacoum (BR) bait application, and liver samples of 1178 non-target small mammals were analyzed for residues of eight ARs using liquid chromatography coupled with tandem mass spectrometry. BR residues were present in 23% out of 742 samples collected during and after baiting. We found clear spatial and temporal exposure patterns. High BR residue concentrations mainly occurred within 15 m from bait stations. Occurrence and concentrations of residues significantly decreased with increasing distance. This pattern was found in almost all investigated taxa. After baiting, significantly more individuals contained residues than during baiting but concentrations were considerably lower. Residue occurrence and concentrations differed significantly among taxa, with the highest maximal residue concentrations in Apodemus species, which are protected in Germany. Although Sorex species are known to be insectivorous we regularly found residues in this genus. Residues of active agents other than brodifacoum were rare in all samples. The confirmation of substantial primary exposure in non-target small mammals close to the baiting area indicates considerable risk of secondary poisoning of predators, a pathway that was possibly underestimated until now. Our results will help to develop risk mitigation strategies to reduce risk for non-target small mammals, as well as their predators, in relation to biocidal AR usage.
The food of foxes in woodland situated partly in suburban Arhus and partly in rural environments was compared using scat analysis. Items found in the 2 areas were mainly the same, but there was a higher frequency of passerine birds scats from woodland edging suburban environments. -from Author
Very many investigations have been made into the diet of the red fox. They all have very different results. This is caused on the one hand by the differing methods, which I shall deal with later on, and on the other by the often very different ecological conditions in the examined biotopes. The fox is able to adapt to considerably different living conditions. According to Heptner and Naumov (1974) it has the greatest geographic and individual versatility of all carnivores, for example it is very much greater than that of the wolf which does not have a smaller range of habitat. General details concerning the diet of the red fox are misleading as they make standards which are only applicable in limited areas.
The resting sites of seven radio-tracked red fox vixens were determined in the Swiss Jura mountains. During their nocturnal active period, foxes rested above ground near their foraging areas. In daytime, some foxes always used dens in areas with little cover; other individuals often rested above ground when cover was abundant. Weather did not influence choice of the resting place, except in extreme conditions. Each fox used several resting places, sometimes moving from one to another during the day, especially when lying above ground. -Authors
The behaviour of the red fox is notable for its flexibility. Populations compared are from Ontario, Canada, and Oxfordshire, England; contrasts are more notable since the landscapes in these areas are superficially similar. Foxes in the 2 populations differed in their territory sizes, adult group sizes, dispersal distances, reproductive parameters, foraging behaviour and interspecific competition. The areas differed in 3 respects which are suggested to underline the observed variation: 1) dispersion and abundance of available prey; 2) pattern and type of fox mortality; and 3) extent of seasonal climatic variation. -from Authors