Beaver Dams and Fallen Trees as Ecological Corridors Allowing Movements of Mammals across Water Barriers-A Case Study with the Application of Novel Substrate for Tracking Tunnels.

Physical obstacles within animal habitats create barriers to individual movements. To cross those barriers, specific corridors are used, some of them created by keystone species such as Eurasian beavers (Castor fiber). Their dams on rivers may also increase habitat connectivity for terrestrial mammals, but the significance of that function has never been quantified. To investigate this, we placed tracking tunnels on beaver dams, fallen trees, and-as a control-on floating rafts. Additionally, we tested kinetic sand as a novel substrate for collecting tracks and found the paws of small mustelids precisely imprinted in that medium, allowing easy identification. However, we needed to lump all shrews and rodents smaller than water voles (Arvicola amphibius) into one category as they can only be detected but not identified. The highest mammalian activity was observed on dams, as they may provide shelter, offering protection from predators during a river crossing or permanent residence, and even the opportunity to hunt invertebrates. Slightly higher diversity was found on logs because of a higher proportion of mustelids, which select exposed locations for scent marking. Our results increase our body of knowledge about the beaver as an ecosystem engineer and provide a novel tool for the monitoring of mammal activity.

The Occurrence of Skin Mites from the Demodecidae and Psorergatidae (Acariformes: Prostigmata) Families in Bats, with a Description of a New Species and New Records.

The bat skin mites from the closely-related Demodecidae and Psorergatidae families occur synhospitally, populating the same host species and perhaps neighboring microhabitats. However, data on their occurrence and parasitism are fragmentary and dispersed. Thus far, 27 Demodecidae and 18 Psorergatidae species have been described, but the coexistence of mites from both families was only demonstrated in six species of bats. This article presents a description of Demodex pusillus sp. nov. from Nyctalus noctula, including a new host record (first observation of demodecid mites in Nyctalus) and a new record concerning the occurrence of Psorergatoides kerivoluae in Plecotus auritus. It also includes an updated global checklist of the occurrence of Demodecidae and Psorergatidae in Chiroptera, including data on their records/distribution and location in their hosts. In both studied families, the mites exhibit preferences, and even topographic specificity, colonizing different microhabitats in the host, including the eye region (e.g., Meibomian glands of the eyes, corneal surface and eyelid vault), wing membranes and hairy skin on the body. Such colonization of separate microhabitats enables different species to co-occur within the same host, while the total number of parasites determines the level of parasite load, with higher levels being associated with the incidence of disease symptoms. It is worth mentioning that Demodex pusillus sp. nov. is the smallest known representative of the Demodecidae family and one of the smallest animals (70-80 micrometers in length).

Variability and repeatability of noctule bat migration in Central Europe: evidence for partial and differential migration.

Each year, large numbers of bats move across Europe between their summer and winter areas, yet even though many of them are endangered and legally protected, we are unaware about many aspects of their migratory behaviour. Here, taking Nyctalus noctula as a model species, we used stable hydrogen isotopic values in fur ( δ2Hf) as an endogenous marker to shed light on the migratory behaviour of more than 1000 bats from hibernacula across Central Europe. Specifically, we asked the following questions: how flexible is migration in temperate zone bats? Which general migration pattern do noctule bats follow? How repeatable and thus predictable is the migratory behaviour of individuals? Do morphological correlates of migration occur in bats? Our study confirmed that noctule bats engage in partial and female-biased migration across Europe, suggesting the strongest migration pressures for northern populations. Further, we revealed a combination of partial and differential migration patterns with highly variable migration distances which lead to a pronounced mixing of different source populations in hibernacula where mating occurs. Most individuals were consistent in their migration strategy over time, i.e. 86% could be repeatedly assigned to either long-distance or regional origin across years. This is consistent with our finding that the between-individual component explained 84% of the variation in δ2Hf values, suggesting specialized individual migratory behaviours and a strong natal philopatry. We discovered a positive correlation between forearm length and migration distance and support for sex-specific effects of migration on body condition. Our study elucidated migration patterns over large geographical scales, demonstrating that considerable numbers of migratory bats originating from distant populations depend on hibernacula across Central Europe, calling for international conservation management.

New data on the distribution of Carios vespertilionis Latreille, 1802 (Ixodida, Argasidae) in bats (Chiroptera) from northern Poland

Carios vespertilionis Latreille, 1802 is a typical bat parasite, widely distributed in the Palearctic, Oriental and Afrotropical realms. Its localities were found throughout Poland, yet it is considerably more common in the south. Currently, 105 bats have been examined, collected in the period 1999­2017 from 27 localities in northern Poland; 102 C. vespertilionis larvae were noted in 6 bats of 3 species of the Pipistrellus genus, originating from 5 localities, of which all constitute new locality for the short-legged bat tick. Instances of C. vespertilionis larvae wintering in the hosts have been observed as well as occurrence of this parasite outside of bat breeding colonies.

Spinturnix dasycnemi (Acari: Spinturnicidae) ­ a poorly known Palaearctic bat mite: first records in Poland and morphometric separation from two other species of the myoti group

Spinturnix dasycnemi (Kolenati, 1856), an ectoparasite considered to be specific to rare and local bat species Myotis dasycneme (Boie, 1825), is reported for the first time in the fauna of Poland. Specimens were collected from M. dasycneme at two localities in the north and central parts of the country. In Europe, only two males of that poorly known mite species have been recorded recently from the Netherlands and Slovakia, while spinturnicids from pond bats were identified as S. andegavina and/or S. myoti in most of previous studies. The exact geographic distribution of S. dasycnemi is unknown, mainly due to the possibility of its common confusion with other mite species, but it may occur in all countries hosting populations of M. dasycneme. We show that specimens of both sexes of S. dasycnemi are morphometrically clearly separable from those of S. myoti and S. andegavina, even based on a combination of idiosoma length and dorsal shield length.

A triple-isotope approach to predict the breeding origins of European bats.

Despite a commitment by the European Union to protect its migratory bat populations, conservation efforts are hindered by a poor understanding of bat migratory strategies and connectivity between breeding and wintering grounds. Traditional methods like mark-recapture are ineffective to study broad-scale bat migratory patterns. Stable hydrogen isotopes (δD) have been proven useful in establishing spatial migratory connectivity of animal populations. Before applying this tool, the method was calibrated using bat samples of known origin. Here we established the potential of δD as a robust geographical tracer of breeding origins of European bats by measuring δD in hair of five sedentary bat species from 45 locations throughout Europe. The δD of bat hair strongly correlated with well-established spatial isotopic patterns in mean annual precipitation in Europe, and therefore was highly correlated with latitude. We calculated a linear mixed-effects model, with species as random effect, linking δD of bat hair to precipitation δD of the areas of hair growth. This model can be used to predict breeding origins of European migrating bats. We used δ(13)C and δ(15)N to discriminate among potential origins of bats, and found that these isotopes can be used as variables to further refine origin predictions. A triple-isotope approach could thereby pinpoint populations or subpopulations that have distinct origins. Our results further corroborated stable isotope analysis as a powerful method to delineate animal migrations in Europe.