Time filter

Source Type

Margalida A.,University of Bern | Margalida A.,Bearded Vulture Study and Protection Group | Carrete M.,Pablo De Olavide University | Hegglin D.,Stiftung Pro Bartgeier | And 4 more authors.
PLoS ONE | Year: 2013

After the quasi-extinction of much of the European vertebrate megafauna during the last few centuries, many reintroduction projects seek to restore decimated populations. However, the future of numerous species depends on the management scenarios of metapopulations where the flow of individuals can be critical to ensure their viability. This is the case of the bearded vulture Gypaetus barbatus, an Old World, large body-sized and long-lived scavenger living in mountain ranges. Although persecution in Western Europe restrained it to the Pyrenees, the species is nowadays present in other mountains thanks to reintroduction projects. We examined the movement patterns of pre-adult non-breeding individuals born in the wild population of the Pyrenees (n = 9) and in the reintroduced populations of the Alps (n = 24) and Andalusia (n = 13). Most birds were equipped with GPS-GSM radio transmitters, which allowed accurate determination of individual dispersal patterns. Two estimators were considered: i) step length (i.e., the distance travelled per day by each individual, calculated considering only successive days); and ii) total dispersal distance (i.e., the distance travelled between each mean daily location and the point of release). Both dispersal estimators showed a positive relationship with age but were also highly dependent on the source population, birds in Andalusia and Alps moving farther than in Pyrenees. Future research should confirm if differences in dispersal distances are the rule, in which case the dynamics of future populations would be strongly influenced. In summary, our findings highlight that inter-population differences can affect the flow of individuals among patches (a key aspect to ensure the viability of the European metapopulation of the endangered bearded vulture), and thus should be taken into account when planning reintroduction programs. This result also raises questions about whether similar scenarios may occur in other restoration projects of European megafauna. © 2013 Margalida et al.


Wibbelt G.,Leibniz Institute for Zoo and Wildlife Research | Kurth A.,Robert Koch Institute | Hellmann D.,University of Oldenburg | Weishaar M.,Bat Conservation Working Group | And 10 more authors.
Emerging Infectious Diseases | Year: 2010

White-nose syndrome is an emerging disease in North America that has caused substantial declines in hibernating bats. A recently identified fungus (Geomyces destructans) causes skin lesions that are characteristic of this disease. Typical signs of this infection were not observed in bats in North America before white-nose syndrome was detected. However, unconfirmed reports from Europe indicated white fungal growth on hibernating bats without associated deaths. To investigate these differences, hibernating bats were sampled in Germany, Switzerland, and Hungary to determine whether G. destructans is present in Europe. Microscopic observations, fungal culture, and genetic analyses of 43 samples from 23 bats indicated that 21 bats of 5 species in 3 countries were colonized by G. destructans. We hypothesize that G. destructans is present throughout Europe and that bats in Europe may be more immunologically or behaviorally resistant to G. destructans than their congeners in North America because they potentially coevolved with the fungus.


Ashrafi S.,University of Bern | Ashrafi S.,University of Tehran | Rutishauser M.,University of Bern | Ecker K.,Swiss Federal Institute of forest | And 5 more authors.
Biodiversity and Conservation | Year: 2013

Assessing the ecological requirements of species coexisting within a community is an essential requisite for developing sound conservation action. A particularly interesting question is what mechanisms govern the stable coexistence of cryptic species within a community, i.e. species that are almost impossible to distinguish. Resource partitioning theory predicts that cryptic species, like other sympatric taxa, will occupy distinct ecological niches. This prediction is widely inferred from eco-morphological studies. A new cryptic long-eared bat species, Plecotus macrobullaris, has been recently discovered in the complex of two other species present in the European Alps, with even evidence for a few mixed colonies. This discovery poses challenges to bat ecologists concerned with planning conservation measures beyond roost protection. We therefore tested whether foraging habitat segregation occurred among the three cryptic Plecotus bat species in Switzerland by radiotracking 24 breeding female bats (8 of each species). We compared habitat features at locations visited by a bat versus random locations within individual home ranges, applying mixed effects logistic regression. Distinct, species-specific habitat preferences were revealed. P. auritus foraged mostly within traditional orchards in roost vicinity, with a marked preference for habitat heterogeneity. P. austriacus foraged up to 4.7 km from the roost, selecting mostly fruit tree plantations, hedges and tree lines. P. macrobullaris preferred patchy deciduous and mixed forests with high vertical heterogeneity in a grassland dominated-matrix. These species-specific habitat preferences should inform future conservation programmes. They highlight the possible need of distinct conservation measures for species that look very much alike. © 2013 Springer Science+Business Media Dordrecht.


Hegglin D.,University of Zürich | Hegglin D.,SWILD Urban Ecology and Wildlife Research | Bontadina F.,SWILD Urban Ecology and Wildlife Research | Bontadina F.,Swiss Federal Institute of forest | Deplazes P.,University of Zürich
Trends in Parasitology | Year: 2015

The life cycle of the zoonotic cestode Echinococcus multilocularis depends on canids (mainly red foxes) as definitive hosts and on their specific predation on rodent species (intermediate hosts). Host densities and predation rates are key drivers for infection with parasite eggs. We demonstrate that they strongly depend on multi-faceted human-wildlife interactions: vaccination against rabies, elimination of top predators, and changing attitude towards wildlife (feeding) contribute to high fox densities. The absence of large canids, low hunting pressure, and positive attitudes towards foxes modify their anti-predator response ('landscape of fear'), promoting their tameness, which in turn facilitates the colonization of residential areas and modifies parasite transmission. Such human factors should be considered in the assessment of any intervention and prevention strategy. © 2014 Elsevier Ltd.


Ashrafi S.,University of Bern | Ashrafi S.,University of Tehran | Beck A.,SWILD Urban Ecology and Wildlife Research | Rutishauser M.,University of Bern | And 3 more authors.
European Journal of Wildlife Research | Year: 2011

Dietary niche partitioning is postulated to play a major role for the stable coexistence of species within a community, particularly among cryptic species. Molecular markers have recently revealed the existence of a new cryptic species of long-eared bat, Plecotus macrobullaris, in the European Alps. We studied trophic niches as well as seasonal and regional variations of diet in eight colonies of the three Plecotus species occurring in Switzerland. Faeces were collected monthly from individuals returning to roost after foraging. Twenty-one arthropod categories were recognized from the faeces. All three species fed predominantly on Lepidoptera, which made up 41%, 87% and 88% (means across colonies) of the diet composition of P. auritus, P. macrobullaris and P. austriacus, respectively. The occurrence of numerous fragments of both diurnal and flightless insects in the diet of P. auritus (but rarely in the diet of the other two species) indicates that this species mostly gleans prey from substrates. P. austriacus and P. macrobullaris are more typical aerial feeders. The latter two species have narrow trophic niches, whilst P. auritus has a much broader diet. Comparison of intraspecific and interspecific niche overlaps in P. auritus and P. macrobullaris in sympatry suggests dietary niche partitioning between these two species. In contrast, the high similarity of the trophic niches of P. austriacus and P. macrobullaris, associated with a typical parapatric distribution, indicates competitive exclusion. The best conservation measures are preservation and restoration of habitats offering a high abundance of moths, the major prey of the three Plecotus species. © 2011 Springer-Verlag.


Fontana S.,Swiss Federal Institute of forest | Fontana S.,University of Basel | Sattler T.,Swiss Federal Institute of forest | Sattler T.,University of Bern | And 3 more authors.
Landscape and Urban Planning | Year: 2011

Urbanization is a fundamental environmental change, today happening at accelerated speed worldwide. Despite the strong and permanent human impact, urban biodiversity has generally proved to be surprisingly high. Quantitative information on the effect of management actions on biodiversity is often lacking but is an indispensable basis for decisions by urban planners and managers. We therefore quantified key urban variables to predict changes in avian biodiversity when their urban habitat is modified. We analysed species richness, diversity (Simpson index) and community composition of 63 bird species with reference to major urban environmental gradients at 96 sampling points in three Swiss cities. Best explanatory models were selected from candidate models following information theory, and their respective predictions were averaged based on AICc-weights. Bird species richness and diversity are negatively affected by increasing fractions of sealed area or buildings, while increasing vegetation structures, in particular trees, show positive effects. Our models predict an increase from 13 species in the absence of trees to 20 species with 46% tree cover (+54%). Coniferous trees help to maximize bird species richness, with the models predicting an increase from 14 species at sites with only deciduous woody plants to 20 species (+43%) at places with equal representation of coniferous and deciduous plants. While the analysis of the Simpson index did not show any influence of the coniferous and broadleaf woody plants mixture, partial redundancy analysis revealed such an influence on bird community composition, highlighting the importance to consider several measures when analyzing biodiversity. © 2011 Elsevier B.V.


Kistler C.,University of Zürich | Hegglin D.,SWILD Urban Ecology and Wildlife Research | Wurbel H.,Justus Liebig University | Konig B.,University of Zürich
Applied Animal Behaviour Science | Year: 2011

Information about the welfare and husbandry of pet and laboratory fish is scarce although millions of fish are sold in pet shops and used in laboratory research every year. Inadequate housing conditions can cause behavioural problems also in fish since they are complex animals with sophisticated behaviour. In this study, we investigated the influence of environmental complexity on compartment preference and behaviour in zebrafish (Danio rerio) and checker barbs (Puntius oligolepis). For the preference test, large aquaria were divided by two semi-transparent walls of Plexiglas into an empty compartment, a structured compartment enriched with plants and clay pots, and a smaller compartment in-between, where food was provided. For observation, the empty and structured compartments were divided into six zones of similar size by defining three vertical layers and two horizontal areas (back vs. front area). Seven groups of six to nine zebrafish and seven groups of seven or eight checker barbs were observed on four days each (within a time period of ten days) to assess compartment use and activity, and to assess behavioural diversity and use of zones within compartments. Both zebrafish and checker barbs showed a significant preference for the structured compartment. Nevertheless, in neither species did behavioural diversity differ between the empty and structured compartment. Zebrafish used all zones in both compartments to the same extent. Checker barbs, however, used the structured compartment more evenly than the empty compartment, where they mainly used the lower and middle zones. These results suggest that zebrafish and checker barbs have a preference for complex environments. Furthermore, they indicate that the behavioural and ecological needs of fish may vary depending on species, and recommendations for husbandry should be specified at species level. © 2011 Elsevier B.V.


Ashrafi S.,University of Bern | Bontadina F.,University of Bern | Bontadina F.,SWILD Urban Ecology and Wildlife Research | Kiefer A.,Johannes Gutenberg University Mainz | And 2 more authors.
Journal of Zoology | Year: 2010

The identification of cryptic species may significantly change our view about their distribution, abundance, ecology and therefore conservation status. In the European Alps, molecular studies have revealed the existence of three sibling species of plecotine bats Plecotus auritus, Plecotus austriacus and, very recently, Plecotus macrobullaris. Knowledge of the ecological niche partitioning of cryptic species is a requisite to develop sound conservation policies. Yet, this requests the development of unambiguous identification methods easily applicable in the field. This study investigates the reliability of several morphological methods used for species recognition and proposes a new identification key for field workers. We captured 214 Plecotus bats from 29 sites in four bioregions within Switzerland, collected biopsy punches for genetic analysis, described and measured external morphological characters. All three species occurred as mono-specific colonies, except at one site where P. auritus and P. macrobullaris shared the same church attic. Qualitative traits alone did not allow a reliable separation of the three species. A series of multivariate analyses conducted on external linear measurements resulted in a discriminant function enabling correct species classification with a 97.5% probability. Compared with genetic analysis, our multivariate morphological method represents a valuable, rapid and cost-effective alternative. © 2010 The Authors. Journal compilation © 2010 The Zoological Society of London.


Weinberger I.C.,University of Zürich | Muff S.,University of Zürich | de Jongh A.,Dutch Otterstation Foundation | Kranz A.,Alka kranz Ingenieurburo fur | And 2 more authors.
Biological Conservation | Year: 2016

Carnivores are threatened worldwide through habitat loss and persecution. Habitat destruction is a major threat for the Eurasian otter. Its populations declined drastically in Europe but are now expanding again, including into the Alps. Here, flood prevention and hydropower have massively altered the riverine landscapes.We evaluated the recovery potential of otters by testing the impact of major factors of habitat transformation and human disturbance on multiple spatial scales. In a hierarchical approach, we investigated spatial use and foraging habitat selection of nine otters in a long-term radiotracking study in the eastern Central Alps. We combined fine scale habitat selection analysis with individual movements by applying a step-selection function approach to the linear river system in a novel way.At home range scale, otters preferred the main riverbeds to abstracted water and tributaries, whereas at fine scale, there was no significant preference for pristine sections within the watercourses. Otters selected for reservoirs in streams with a width smaller than 12 m and otherwise preferred foraging in residual waters and stretches with main discharge.At this stage of recovery, otters show a surprising flexibility in their habitat selection. This is promising for the species' future expansion into former abandoned areas. However, given that the traditional fish stocking regime might contribute to this recovery by providing profitable hunting grounds after stocking events, there is an increased risk of human-wildlife conflicts. Our results demonstrate a high adaptability of a threatened carnivore to altered landscapes and show how this flexible behaviour opens opportunities for recovery. © 2016 Elsevier Ltd.


Reiter G.,Austrian Coordination Center for Bat Conservation and Research | Polzer E.,Austrian Coordination Center for Bat Conservation and Research | Polzer E.,University of Graz | Mixanig H.,Austrian Coordination Center for Bat Conservation and Research | And 3 more authors.
Mammalian Biology | Year: 2013

For habitat specialists, fragmentation has major consequences as it means less suitable habitat for the species to live in. In a fragmented landscape, we would expect larger, but spatially more clustered, foraging ranges. We studied the impact of landscape fragmentation on the foraging range and habitat exploitation of a specialised forest bat by radiotracking 16 female lesser horseshoe bats Rhinolophus hipposideros in a landscape with connected woodland structures and in a highly fragmented landscape in Carinthia, Austria. Contrary to our expectations, spatial foraging behaviour was not influenced by fragmentation. No differences in the behaviour of the bats between the sites were evident for the foraging ranges (minimum convex polygon, MCP), the core foraging areas (50% kernel), nor the mean or the maximum distances from the roost. However, in the highly fragmented landscape, the foraging activity of individuals was spatially more clustered and the overall MCP of all bats of a colony was greater compared to the less fragmented landscape. Woodland was the most important foraging habitat for the lesser horseshoe bats at both study sites. Habitat selection at the individual MCPs was evident only at the site with low fragmentation. However, in the core foraging areas, woodland was significantly selected over all other habitat types at both study sites. We conclude that (1) conservation measures for colonies of lesser horseshoe bats should be undertaken within 2.5. km of the nursery roost, (2) woodland is the key foraging habitat particularly in the vicinity of the roost, and (3) any loss of woodland near the colonial roosts are likely to negatively influence the colony, since these bats do not seem to be able to adapt their spatial foraging behaviour in a degraded landscape. The inflexible spatial behaviour of this specialised bat highlights the need to compensate for any habitat loss within the foraging range of a bat colony. © 2012 Deutsche Gesellschaft für Säugetierkunde.

Loading SWILD Urban Ecology and Wildlife Research collaborators
Loading SWILD Urban Ecology and Wildlife Research collaborators