Zdeněk Řehák

Increasing Incidence of Geomyces destructans Fungus in Bats from the Czech Republic and Slovakia

Background White-nose syndrome is a disease of hibernating insectivorous bats associated with the fungus Geomyces destructans. It first appeared in North America in 2006, where over a million bats died since then. In Europe, G. destructans was first identified in France in 2009. Its distribution, infection dynamics, and effects on hibernating bats in Europe are largely unknown. Methodology/Principal Findings We screened hibernacula in the Czech Republic and Slovakia for the presence of the fungus during the winter seasons of 2008/2009 and 2009/2010. In winter 2009/2010, we found infected bats in 76 out of 98 surveyed sites, in which the majority had been previously negative. A photographic record of over 6000 hibernating bats, taken since 1994, revealed bats with fungal growths since 1995; however, the incidence of such bats increased in Myotis myotis from 2% in 2007 to 14% by 2010. Microscopic, cultivation and molecular genetic evaluations confirmed the identity of the recently sampled fungus as G. destructans, and demonstrated its continuous distribution in the studied area. At the end of the hibernation season we recorded pathologic changes in the skin of the affected bats, from which the fungus was isolated. We registered no mass mortality caused by the fungus, and the recorded population decline in the last two years of the most affected species, M. myotis, is within the population trend prediction interval. Conclusions/Significance G. destructans was found to be widespread in the Czech Republic and Slovakia, with an epizootic incidence in bats during the most recent years. Further development of the situation urgently requires a detailed pan-European monitoring scheme.

Influence of the microclimate of bat boxes on their occupation by the soprano pipistrelle Pipistrellus pygmaeus: possible cause of roost switching.

ABSTRACT Between April and October 2003–2004, the changes in occupation of three bat boxes used by Pipistrellus pygmaeus were studied using a passive IR monitors and data loggers. Bat boxes were situated in a floodplain forest in south-eastern Moravia. Generalized additive models indicated that internal humidity described better the fluctuation in bat numbers during pregnancy and lactation than did changes in the internal temperature. Three variables (internal humidity, external temperature, and number of bats) described 87% of the variability in internal roost temperature, while the number of bats described only 29% of the variability. A negative correlation was found between the internal temperature and the number of bats roosting in a bat box the next day during pregnancy and lactation. The number of bats was also positively correlated with the internal humidity. The internal temperature of a roost with bats was biased by temperature strategies induced by the bats during particular reproductive periods. Mean temperature of occupied bat boxes was higher during pregnancy than during lactation. Females were able to go into torpor even during lactation period.

Flight activity and habitat use of Pipistrellus pygmaeus in a floodplain forest

Seasonal and overnight changes in flight activity and habitat use of Pipistrellus pygmaeus were studied in the floodplain forest in south-eastern Moravia (Czech Republic) during the season 2001 using bat detectors. The night was divided into thirds; during each one bat activity was recorded in selected habitats, i.e. ecotones, water bodies, meadows inside the forest, forest paths and dense forest. The season was also divided into four parts with respect to the reproduction of bats, i.e., pregnancy, lactation, post-lactation and movement period. The highest activity was recorded at the beginning of the night (1st third). During the 2nd third, flight activity was very low throughout the whole season. The level of activity increased after the parturition during the 3rd third. The seasonal course in activity showed a bimodal pattern along edges and inside the forest with the first peak in spring (May) and the second one at the end of summer (August). On the contrary, the level of foraging activity varied at water surfaces although it was permanently higher in comparison with activity in other habitats. Flight activity was well-balanced in the close forest and over forest paths and was much lower than over water. Very low activity was also registered over the meadows throughout the season.

Bat casualties by road traffic (Brno-Vienna)

We studied the impact of road E461, Brno-Vienna, on bat mortality, with the goal to predict this impact after the road has been reconstructed and turned into highway, R52. In the Czech territory, two proposed road sections of E461 were selected, 3.5 and 4.5 km long, and divided into segments 100 m in length. Bat carcasses were picked up from emergency stopping lanes, and bat activity was recorded by ultrasound detectors along the road and 100 m away on both sides from the central strip. From May to October 2007, 25 checks of bat mortality performed at weekly intervals revealed 119 bat carcasses representing 11 or 12 species.Pipistrellus nathusii, P. pygmaeus andMyotis daubentonii were the most frequent traffic casualties. The greatest mortality was documented from early July to mid-October, with a peak in September. Monitoring bat activity by ultrasound detectors (one night per month in May, June and September) yielded 12 bat species and 3 species couples (Myotis mystacinus/brandtii, M. emarginatus/alcathoe, Plecotus auritus/austriacus), mostly the same taxa as found dead on the road. Significantly greater bat numbers were revealed in the section where the road was situated between two artificial lakes, as compared to a road section without any lakes directly adjacent to the road. In the former section, significant correlation was found between the number of carcasses found and the activity detected, according to road segments.

Diet composition and foraging activity of Pipistrellus pygmaeus in a floodplain forest

In 2000–2002 bat droppings were collected under the emerging crevice of a nursery colony of Pipistrellus pygmaeus. The locality was situated in a floodplain forest at the confluence of the Dyje and Morava rivers (S Moravia, Czech Republic). In total, 27 samples (20 pellets in one sample) of droppings were used to analyze prey remains. In the diet, 40 taxonomic groups of invertebrates were found. As expected, small dipteran insects were the main food item in which Nematocera dominated. Besides Chironomidae and Ceratopogonidae also a high percentage of nematoceran eggs were recorded. Surprisingly, a relatively high percentage of Brachycera was recorded. Further frequent prey items belonged to the orders of Trichoptera, Hymenoptera, Coleoptera and Sternorrhyncha. A heterodyne bat detector was used to follow foraging activity of P. pygmaeus on line transects in forest and water habitats in the vicinity of the colony. A significant decrease in foraging activity over water habitats and in forest sites during the late pregnancy (mid-May — early June) and an increase during the lactation and post-lactation periods (mid-June — early August) were found. Changes in the frequency of occurrence of Chironomidae, Neuroptera, Trichoptera, Aphidinea and Simuliidae were correlated with the bats’ foraging activity.

Roost switching and activity patterns in the soprano pipistrelle, Pipistrellus pygmaeus, during lactation

We studied roost switching and habitat selection of 16 P. pygmaeus females tagged in two nursery colonies. There were differences in overnight roosting and flying. The highest foraging activity was observed over water bodies, at forest edges and near street lamps. During each night, each female visited at least one night-roost, and five females regularly visited two roosts. On average, the females visited a roost 3.7 times per night. After parturition, the distances between night roosts and day roosts increased. The number of night roosts used declined as pups neared weaning. Five females changed day roosts after two nights. Based on the observation of flightless young in new roosts a conclusion was reached that some females transported their offspring to new roosts at night. After lactation began, some females visited roosts occupied by vocalizing males of P. pygmaeus and P. nathusii.

A rapid PCR-based test for species identification of two cryptic bats Pipistrellus pipistrellus and P. pygmaeus and its application on museum and dropping samples

ABSTRACT The identification of two cryptic bat species of the genus Pipistrellus using a non-destructive and quick method of multiplex PCR and agarose gel electrophoresis is described. Two primer combinations were able to produce species-specific bands that identified reliably individuals that were previously identified by mtDNA sequencing. Robustness of the method was subsequently successfully tested on 16 randomly selected free-living animals from central Europe (tissue samples obtained from a 3 mm punch of wing-membrane) identified to species on the basis of echolocation calls. Nine out of 15 museum specimens and 100% of fresh faecal samples from seven individuals were also successfully identified by this method. The described method thus provides a good way to routinely distinguish two Pipistrellus species by using non-destructive sampling of living individuals or droppings, and will be used in field studies of their ecology.

Do two cryptic pipistrelle bat species differ in their autumn and winter roosting strategies within the range of sympatry

Abstract. n Large hibernating aggregations and behaviour called late summer or autumn “invasions” when large groups of bats enter buildings are known in pipistrelles. We investigated differences in roosting behaviour between two cryptic species (common pipistrelle, Pipistrellus pipistrellus, and soprano pipistrelle, Pipistrellus pygmaeus) during autumn and winter periods. In total 463 bats were sampled in both caves and buildings with temporary occurrence during the period of late summer and autumn mating and presumable migrations from late July to September (10 sites), and in all known types of hibernacula from late November to March (34 sites). Sampling sites were located within the Czech Republic, Slovakia, Serbia and Romania in areas where the two species occur sympatrically throughout the summer. Using a DNA-based identification method, all but four individuals were identified as P. pipistrellus. It means that winter roosts of P. pygmaeus remain largely unknown in the area. Similarly, no P. pygmaeus was found in the “invasion” assemblages. Very abundant groups of P. pipistrellus in underground hibernacula and its exclusive occurrence in sites of “invasions” suggest that roosting behaviour during this time may be species-specific.

Deeply torpid bats can change position without elevation of body temperature

Because body temperature is tightly coupled to physiological function, hibernating animals entering deep torpor are typically immobile. We analysed thermal behaviour and locomotory activity of hibernating greater mouse-eared bats Myotis myotis and found two types of movement behaviour related to body temperature, i.e. movement at high fur temperature and at low fur temperatures (Tflow; <5°C). First Tflow movements appeared at the beginning of March and often occurred during long torpor bouts. In most cases, Tflow events represented slow displacements between clusters of bats. In several cases, however, departure or arrivals from and into clusters was also recorded without any elevation in body temperature. Distance travelled, flight duration and speed of locomotion during Tflow events was lower than in high fur temperature events. Such behaviour could allow bats to save energy long-term and prolong torpor bouts. Tflow movement in torpid bats significantly changes our understanding of basic hibernation principles and we strongly recommend further studies on the subject.