Trophic niche partitioning of cryptic species of long-eared bats in Switzerland: implications for conservation

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 specie

Colorful Collar-Covers and Bells Reduce Wildlife Predation by Domestic Cats in a Continental European Setting

In many areas, domestic cats are the most abundant predators of small vertebrates. Due to the potential impact on prey populations by cats, there are calls to investigate the effectiveness of visual and acoustic cues as measures to reduce the cat’s hunting efficiency. In this study, we complement previous studies on the efficacy of Birdsbesafe collar-covers (BBScc) in a so far not investigated Continental European setting and explore the effectiveness in combination with a bell. We also evaluate the tolerability of these devices by the cat and the acceptance by their owners. With a randomized and comparative citizen science-based approach we collected data from 26 households with 31 study cats, which were wearing either a BBScc or both a BBScc and a bell. The BBScc reduced the number of birds brought home by 37% (probability of reduction of 88%). The number of mammals brought home was reduced by 54–62%, but only with the additional bell (probability of reduction of >99%). About one fourth of the birds that could be dissected were found to have collided with a hard object prior to having been brought home by the cats. Our results are in line with previous findings from Australia, the United States, and the United Kingdom and highlight the great potential of visual and acoustic cues in reducing hunting success in domestic cats also in Continental Europe. On the other hand, our result show that the number of prey brought home by cats overestimates their hunting bag, if scavenging is not considered. The majority of cat owners reported that their cats habituated quickly to the BBScc. However, frequent scratching in some cats indicates that some individuals may not habituate. Most participating cat owners had a positive attitude toward the BBScc and said that they were willing to use it after the study. However, cat owners reported that their social environment (e.g., neighbors, family, friends) was relatively skeptical, which indicates a need for communication. To conclude, commercially available devices with visual and acoustic stimuli are straightforward and effective ways to mitigate the potentially harmful effect of domestic cats on wildlife

Habitat selection of three cryptic Plecotus bat species in the European Alps reveals contrasting implications for conservation

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 4.7km 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 alik

Identifying Key Research Objectives to Make European Forests Greener for Bats

Bats are a biodiverse mammal order providing key ecosystem services such as pest suppression, pollination, and seed dispersal. Bats are also very sensitive to human actions, and significant declines in many bat populations have been recorded consequently. Many bat species find crucial roosting and foraging opportunities in European forests. Such forests have historically been exploited by humans and are still influenced by harvesting. One of the consequences of this pressure is the loss of key habitat resources, often making forests inhospitable to bats. Despite the legal protection granted to bats across Europe, the impacts of forestry on bats are still often neglected. Because forest exploitation influences forest structure at several spatial scales, economically viable forestry could become more sustainable and even favor bats. We highlight that a positive future for bat conservation that simultaneously benefits forestry is foreseeable, although more applied research is needed to develop sound management. Key future research topics include the detection of factors influencing the carrying capacity of forests, and determining the impacts of forest management and the economic importance of bats in forests. Predictive tools to inform forest managers are much needed, together with greater synergies between forest managers and bat conservationists

Human-wildlife interactions and zoonotic transmission of Echinococcus multilocularis

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

The lesser horseshoe bat in Switzerland THE LESSER HORSESHOE BAT RHINOLOPHUS HIPPOSIDEROS IN SWITZERLAND: PRESENT STATUS AND RESEARCH RECOMMENDATIONS

ABSTRACT Once the lesser horseshoe bat Rhinolophus hipposideros (Bechstein, 1800) was known to be widespread and common in Switzerland. In the past 50 years their overall population has undergone a severe decline, as in most countries of Central Europe. With the aim to Following an evaluation of possible factors and an enquiry with bat experts, the most threatening factors are thought to be pesticides, changes in the structure of habitats and food shortage. Therefore we propose the following research topics with high priority: resource exploitation, pesticide contamination and the development and implementation of refined methods for monitoring populations. Moreover, depending on the results of the first research phase, studies about population dynamics, roost conditions, climate, populations genetics and the colonisation potential of these animals could be included in a second phase. Further we propose to carry out regional public enquiries to find more roosts in private houses and to build action plans to implement protection schemes

Riparian vegetation provides crucial shelter for resting otters in a human-dominated landscape

The riparian vegetation belt is one of the few remaining structures that provide coverage for wildlife in many anthropogenic landscapes. It provides shelter for many species and functions as corridors for dispersal. However, this landscape is increasingly utilised by humans for leisure activities. The loss of riparian vegetation with a concurrent increase of human disturbance in these habitats can pose a serious threat to wildlife. One of the species potentially affected is the Eurasian otter Lutra lutra. In the Alps, otters are nocturnal and rest during the day when human activity is high. To study the impact of human presence on resting site selection in otters, we radio-tracked nine otters for up to 30 months in the eastern Central Alps of Austria. We analysed resting site selection in relation to human disturbance. Altogether, we identified 285 resting sites scattered throughout the territories of the individual otters at an average distance of 144 m between sites. Almost all the resting sites (95%) were located in the natural riparian vegetation, making this the most important habitat for resting otters. We found evidence that human disturbance within these riparian habitats shapes resting site selection. Otters preferred narrow riparian strips when there was no human presence, but selected areas with a wider vegetation belt when the disturbance level increased. Outside the vegetation period, animals rested below ground more often than above, which suggests that vegetation also functions as visual cover. Our study highlights the importance of the restoration of the natural riparian vegetation belt for the protection of wildlife, particularly where human activities are intense. We provide information for the effective conservation management of otters considering the combination of spatial distribution of resting sites and specific habitat requirements in the presence of human disturbance. Areas of conservation importance chosen in this way are likely to benefit other wildlife that utilise the riparian vegetation belt