Krzysztof Piksa

Swarming of Myotis mystacinus and other bat species at high elevation in the Tatra Mountains, southern Poland

ABSTRACT This paper reports a study of the visitation of bats to Great Litworowa Cave (1,907 m a.s.l., Tatra Mts., southern Poland) during summer and autumn 1999–2005. A total 5,608 bats representing 11 of Polands 25 species were captured. Myotis mystacinus predominated. Its activity at all times was high. However, the species composition and number of other bats changed seasonally. Swarming activity lasted between July and November, peaking in late July and August. Nightly activity peaked between 22.00 and 02.00 hrs and then gradually decreased toward dawn. Strong male bias was observed. Myotis mystacinus showed regular changes in sex and age ratios. Rare species such as M. bechsteinii, M. emarginatus, and Vespertilio murinus were recorded. This cave is the highest locality of M. bechsteinii and M. brandtii in Europe. Some behavioural observations including copulation, drinking and daylight activity were recorded. The role of swarming activity is discussed in light of the findings. Some observations suggest that this activity of bats is connected with mating; some other observations provide evidence that the function of swarming is also to facilitate the location of mates and/or to assess suitable hibernacula.

Swarming of bats at different elevations in the Carpathian Mountains

Swarming bat activity was monitored at three caves at elevations ranging from 880 m to 1,907 m above sea level in the Carpathian Mountains, using an infrared light barrier with data-logger, a video camera with a night-scope system, and subsequently by mist netting. A total of 6,175 bats of 19 species was captured, and over 70,000 passes through cave openings were registered. Caves differed in bat species richness, sex ratio, abundance of particular species and species composition. Peak species richness was observed in the mid-elevation cave. Bat activity was high in all caves, but declined with increasing altitude. Swarming activity occurred earlier at high elevation than at lower elevations. Activity of boreal-alpine species, such as Eptesicus nilssonii, peaked at the start of the swarming period, that of species typical of lower elevations, such as Myotis emarginatus, peaked in the middle of the swarming season. In a few species, males showed a significant preference for higher altitude caves, in contrast to females. A similar pattern was observed in the proportion of adults to juveniles, which increased with increasing elevation. Our results also suggest that M. brandtii and M. alcathoe were more often encountered at lower elevations, M. mystacinus (sensu stricto) at higher ones.

Hybridization Hotspots at Bat Swarming Sites

During late summer and early autumn in temperate zones of the Northern Hemisphere, thousands of bats gather at caves, mainly for the purpose of mating. We demonstrated that this swarming behavior most probably leads not only to breeding among bats of the same species but also interbreeding between different species. Using 14 nuclear microsatellites and three different methods (the Bayesian assignment approaches of STRUCTURE and NEWHYBRIDS and a principal coordinate analysis of pairwise genetic distances), we analyzed 375 individuals belonging to three species of whiskered bats (genus Myotis) at swarming sites across their sympatric range in southern Poland. The overall hybridization rate varied from 3.2 to 7.2%. At the species level, depending on the method used, these values ranged from 2.1–4.6% in M. mystacinus and 3.0–3.7% in M. brandtii to 6.5–30.4% in M. alcathoe. Hybrids occurred in about half of the caves we studied. In all three species, the sex ratio of hybrids was biased towards males but the observed differences did not differ statistically from those noted at the population level. In our opinion, factors leading to the formation of these admixed individuals and their relatively high frequency are: i) swarming behaviour at swarming sites, where high numbers of bats belonging to several species meet; ii) male-biased sex ratio during the swarming period; iii) the fact that all these bats are generally polygynous. The highly different population sizes of different species at swarming sites may also play some role. Swarming sites may represent unique hybrid hotspots, which, as there are at least 2,000 caves in the Polish Carpathians alone, may occur on a massive scale not previously observed for any group of mammal species in the wild. Evidently, these sites should be treated as focal points for the conservation of biodiversity and evolutionary processes.

First case of human infestation by the tick Ixodes vespertilionis (Acari: Ixodidae)

Human infestation by the bat tick Ixodes vespertilionis (Acari: Ixodidae) is described; this is the first recorded case of this tick parasitizing humans.

Genetic structure in three species of whiskered bats (genus Myotis) during swarming

Abstract We studied the population structure of 3 species in the Myotis mystacinus complex (M. mystacinus, M. brandtii, and M. alcathoe) during the swarming period by sampling bats at 27 caves in the Carpathian Mountains and adjacent areas in southern Poland using 14 or 15 nuclear microsatellite loci. None of the examined species were in Hardy–Weinberg equilibrium following the global test for heterozygote deficiency. Inbreeding coefficient (FIS) values at the species level also were statistically greater than zero. This may indicate some level of inbreeding in all examined taxa although it seems to be relatively low because significant FIS values were recorded in only 2 swarming sites of M. mystacinus, 2 sites of M. brandtii, and 3 sites of M. alcathoe. However, almost 10% of related individuals sharing 1 parent (i.e., half siblings) were found in the same swarming sites for M. mystacinus and M. brandtii, with fewer observed in M. alcathoe. At the population level, 4.1%, 5.9%, and 8.7% of individuals of M. mystacinus, M. brandtii, and M. alcathoe, respectively, were assigned as full siblings. These figures suggest the possibility of females mating selectively with the same male in more than 1 year.

Biogeography of the recently described Myotis alcathoe von Helversen and Heller, 2001

ABSTRACT Since its description in 2001 Alcathoes myotis (Myotis alcathoe) was recorded from several locations across Europe. Here we describe the first records of this species from Germany, Poland, Albania, and from the European part of Turkey, including the northernmost locality in central Germany (51°23′N, 11°01′E). Compilation of all up-to-date records shows that M. alcathoe has a wide European distribution although it seems to be rare at most places. The habitats where the bat was recorded are natural, moist and deciduous forests with old trees and water streams as can be found, for example, in canyons or forests of alluvial origin. Such habitats suggest that the species probably has a more continuous and wider distribution than currently known and might be expected to occur even further to the North.

Nonlinear Distribution Pattern of Hibernating Bats in Caves along an Elevational Gradient in Mountain (Carpathians, Southern Poland)

Background Thermal gradients along changes in elevation in mountainous environments are reflected by different biotas. Although there have been studies of elevation variation in bat assemblages in summer, winter changes in the same gradients remain unknown. Methodology/Principal Findings The objective of this study was to document changes in the species composition of bats hibernating in caves along a temperate elevational gradient. We studied 70 caves between from 300 m to 1,930 m altitude along a slope of the Carpathian Mountains in southern Poland. We recorded changes in bats, including species richness, abundance, altitudinal distribution and dominance during consecutive winters between 2003 and 2009. Similarity of dominance of faunal structure was assessed by using the Bray-Curtis similarity index. We used the generalised additive model and rarefaction to study the variation in species richness, and generalized additive mixed models to examine the effect of abiotic factors on the qualitative and quantitative structure of bat assemblages. During 351 surveys we recorded 13,856 hibernating bats from 15 species. Species richness peaked around mid-elevation (1,100–1,400 m a.s.l.) with richness declining at both higher and lower elevations. Based on the results of a cluster analysis, we could distinguish among four altitudinal zones that differed in species richness and dominance structure. Conclusions/Significance This is the first study documenting changes in species richness and variation of structure of bats hibernating in caves along an elevational gradient. The most surprising and key finding is the fact that changes in the structure of assemblages of hibernating bats along the altitudinal gradient occurred in jumps, forming zones similar to those observed in the vegetation zones. Moreover, species richness and dominance structure of assemblages of hibernating bats in the mountains depended not only on location above sea level, but also on local geomorphologic conditions which strongly affected the microclimate of the caves.

Detection of Borrelia burgdorferi sensu lato and spotted fever group rickettsiae in hard ticks (Acari, Ixodidae) parasitizing bats in Poland.

A total of 491 Ixodes vespertilionis and 8 Ixodes ricinus collected from bats and cave walls in southern Poland between 2010 and 2012 were examined by the polymerase chain reaction for tick-transmitted pathogens. PCR analysis for Borrelia burgdorferi s.l., Rickettsia spp., and Anaplasma phagocytophilum yielded negative results for all I. vespertilionis. DNA of Rickettsia helvetica was detected in three specimens of I. ricinus attached to Rhinolophus hipposideros or Myotis myotis, while Borrelia garinii was found in one tick parasitizing Myotis daubentonii. These pathogens were recorded for the first time in hard ticks that parasitized bats.

The patterns of seasonal activity of Ixodes vespertilionis (Acari: Ixodidae) on Rhinolophus hipposideros in nursery colonies.

The aim of this study was to describe the dynamics of the long-legged bat tick Ixodes vespertilionis infestation on the lesser horseshoe bat Rhinolophus hipposideros in 2 nursery colonies roosting in attics. Out of a total of 810 lesser horseshoe bats examined, 217 (26.8%) were found to be infested with a total of 464 I. vespertilionis individuals. The developmental stage most frequently found was the larva, followed by the nymph, and the adult female. Bats were significantly more frequently infested with I. vespertilionis ticks in the period April to May than in other months. In these months, all tick developmental stages were observed. During summer and autumn, only immature developmental stages were recorded, whilst in September and October larvae predominated. Considerable differences in tick load between nursery colonies were observed. The length of seasonal presence on bats, prevalence, and infestation intensity of I. vespertilionis on lesser horseshoe bats were higher in the nursery colony situated in close vicinity of a cave than in the colony situated far from the caves. The results suggest that the pattern of seasonal infestation of ticks on bats roosting in nursery colonies coincides with the seasonal activity of Rh. hipposideros in the caves. The first case of mixed infestation of the lesser horseshoe bat with I. vespertilionis and I. ricinus were also recorded.

Two spinturnicid mites new to the fauna of Poland (Acari: Spinturnicidae)

Two spinturnicid mites new to the fauna of Poland (Acari: Spinturnicidae) Eyndhovenia euryalis oudemansi (Eyndhoven, 1941) and Spinturnix emarginata (Kolenati, 1856) (Acari: Mesostigmata: Spinturnicidae) are reported in the Polish fauna for the first time. They were collected from the bat Myotis emarginatus (Geoffroy, 1806) in the Carpathians, Sudety Mts and Kraków Upland (S. Poland).