Peter Kaňuch

Altitudinal distribution of bats in the Pol’ana Mts area (Central Slovakia)

In May — August, bats were mist-netted along an altitudinal gradient of 350–1350 m a.s.l. in the Pol’ana Mts area, to verify the correlation of species number decrease and the increase in elevation, to find which species could be predictors of certain altitude levels and to compare the sexual occurrence of species in various altitudes. Seventeen bat species were recorded. The most abundant mist-netted species were Myotis daubentonii (16%), M. myotis (13%) and M. mystacinus (12%). Otherwise, the most frequently caught species were M. mystacinus (40%), Eptesicus serotinus, M. myotis (26%) and Nyctalus leisleri (23%). In this study at a local scale, from oak to spruce vegetation stages, decreasing number of species with increasing altitude was found. Species dominance of the individual altitudinal levels was significantly different (15 species up to 600 m a.s.l., six species over 1100 m a.s.l.). The results indicated that the occurrence of some bat species, due to their ecological adaptations, is more or less characteristic for higher or lower altitudes of the Western Carphathians. The “lowland” species were considered to be mainly E. serotinus, Pipistrellus pipistrellus, N. noctula, N. leisleri and M. daubentonii. In higher elevations (more than 850 m), the presence of reproductive females was not found, of all but one, N. noctula, of the “lowland” species which are breeding in the area. The “mountain” species were considered to be E. nilssonii and Plecotus auritus. The general occurrence and reproduction of M. mystacinus and Barbastella barbastellus, was not limited by elevation.

Response of Orthoptera assemblages to management of montane grasslands in the Western Carpathians

Montane grassy habitats in the Western Carpathians are relatively well preserved, maintain high species richness and are often important in accordance to the nature conservation policy in Europe. However, knowledge about the impact of farming on the habitat quality there is rather poor. The influence of various management types (permanent sheep pen, irregular grazing, mowing) on Orthoptera diversity and species determining assemblages of these habitats were analysed on 72 plots in Poľana Mts Biosphere Reserve. Altogether, 36 Orthoptera species (15 Ensifera, 21 Caelifera) were found, whereas the highest number of species was found on plots with irregular grazing (28 species), followed by plots with mown grass (17) and permanent sheep pens (14). All four measures of the assemblages’ diversity confirmed significant differences. Using Discriminant Function Analysis, correct classification rate of Orthoptera assemblages was unambiguous according to the type of management. Each form of the management harboured several characteristic species. Thus implications regarding the biodiversity conservation and grassland management were given.

Landscape configuration determines gene flow and phenotype in a flightless forest-edge ground-dwelling bush-cricket, Pholidoptera griseoaptera

Spatial configuration of habitats influences genetic structure and population fitness whereas it affects mainly species with limited dispersal ability. To reveal how habitat fragmentation determines dispersal and dispersal-related morphology in a ground-dispersing insect species we used a bush-cricket (Pholidoptera griseoaptera) which is associated with forest-edge habitat. We analysed spatial genetic patterns together with variability of the phenotype in two forested landscapes with different levels of fragmentation. While spatial configuration of forest habitats did not negatively affect genetic characteristics related to the fitness of sampled populations, genetic differentiation was found higher among populations from an extensive forest. Compared to an agricultural matrix between forest patches, the matrix of extensive forest had lower permeability and posed barriers for the dispersal of this species. Landscape configuration significantly affected also morphological traits that are supposed to account for species dispersal potential; individuals from fragmented forest patches had longer hind femurs and a higher femur to pronotum ratio. This result suggests that selection pressure act differently on populations from both landscape types since dispersal-related morphology was related to the level of habitat fragmentation. Thus observed patterns may be explained as plastic according to the level of landscape configuration; while anthropogenic fragmentation of habitats for this species can lead to homogenization of spatial genetic structure.

Body size patterns of Pholidoptera frivaldskyi (Orthoptera) in very isolated populations

Abstract We studied geographical body-size variation and sexual size dimorphism in three isolated populations of the bush-cricket Pholidoptera frivaldskyi in Central Europe (Slovakia). We measured six body traits in females and seven in males, from 93 individuals (46 males and 47 females): lengths of body, right hind femur, right hind tibia, pronotum, right cercus or ovipositor, length of wing (only in males) and body weight. Not all linear traits in both sexes were correlated with body weight. Generally, females were significantly bigger than males in all parameters. Although discriminant function analysis indicated some significant differences in male traits, there were no strong morphological difference among local populations. Morphological variability among the three populations was not higher than that within populations. This relative somatic uniformity should be verified on the level of genetic variability of the studied populations, since cryptic species diversity can be expected.

Dawn Swarming in Tree-Dwelling Bats — An Unexplored Behaviour

In colonial tree-dwelling bats, is vital to prevent disintegration of the group during frequent roost-switching. Thus some mechanisms which maintain group cohesion are expected. Dawn swarming is a set of behavioural displays observed in many such bats before they enter the roost. It is suggested that this behaviour plays a role in transferring information about the roost position. However this phenomenon had not been explored in detail. Based on qualitative and quantitative description of behaviour we suggest its potential function. Using field-based video-recordings of swarming sessions made on maternity colonies of Leislers bat (Nyctalus leisleri), we constructed ethograms which revealed remarkably similar behavioural sequences among individuals. For more than two hours prior to sunrise, individual flybys in front of the roost entrance predominated, followed by landings and leaps, which preceded the final entering of the roost. Interestingly, no obvious peak of behavioural activity was found at any particular time during swarming but a wave-like pattern was observed. We suggest that individuals are swarming in close proximity to the roosting tree with some purpose, most probably serving as a beacon for other group members and thus marking the current location of the roost.

Swarming behaviour associated with group cohesion in tree-dwelling bats

Group living of social species increases the individual survival rate and enhances optimal exploitation of resources within their environment. Groups of cryptic tree-dwelling bats perform frequent roost switching on relatively long distances, whereas groups are temporarily disintegrated during foraging that precedes moving into new roost. In this study, we attempted to elucidate a mechanism in which group members can select new roost from a large set of potential roosting sites without disintegration of the whole group. Exploring the activity at the front of the tree hollows, recorded by automatic infrared monitors, we found that the swarming activity of Leislers bats was performed during the whole night and was concentrated before the civil twilight at occupied roosts. A generalized linear model revealed significant positive association between the group size and swarming activity while season had negative but smaller effect. As bats swarmed the whole night also at sites that were less occupied or even unoccupied, we suggest that members of a bat colony selected new roost from a potentially larger set of available roosting sites. Thus, we propose a possible signalling role of swarming as a threshold behaviour that ensures group cohesion during roost switching.

Female Bush-Crickets, Pholidoptera griseoaptera, that have Received Smaller Ejaculates Show a Higher Mating Rate in the Field

Females of numerous insect species are known to be polyandrous, but there have been relatively few studies of factors associated with the degree of polyandry in females in the field. Number of copulations by females is negatively associated with ejaculate size across bush-cricket species. Assessing intraspecific variability is important when looking for and interpreting trait evolution. Therefore the aim of this study was to test the association between ejaculate size (i.e. volume of spermatodose–spermatophore-like structure formed within the spermatheca) and mating rate (i.e. number of spermatodoses) of females of Pholidoptera griseoaptera, while accounting for female body size (pronotum length) and age (number of hind leg’s cuticular bands). The results based on field-caught individuals suggested that there were statistically significant negative association between smallest and mean spermatodose volume, respectively, and number of copulations in this nuptial gift-giving bush-cricket species. This is in accordance with interspecific associations between ejaculate size and polyandry. However, lower slope of the intraspecific relationship may suggest lower importance of the ejaculate size in explaining females’ mating rate variability in this nuptial gift-giving species.

New discoveries on the ecology and echolocation of the heart-nosed bat Cardioderma cor with a contribution to the phylogeny of Megadermatidae

In this study we report findings in roosting ecology, ectoparasites, echolocation characteristics and the phylogenetic position of Cardioderma cor, an impressive bat species that is distributed throughout the savannas and woodlands of eastern Africa. For individuals caught in Mago National Park, Ethiopia, we recorded broadband frequency-modulated ultrasound signals having very short duration (2 ms) with three harmonic components. The mean peak frequency of the first harmonic was 50.4 kHz and the mean inter-signal interval was 186 ms. Phylogenetic reconstructions of all known species from the family Megadermatidae based on DNA sequences of two mitochondrial and four nuclear genes yielded incongruent topologies (both Bayesian inference and maximum likelihood analysis) with only weak support for nodes. The phylogeny that combined all six loci into a species tree was not congruent with any previous inference based on dental or cranial characteristics, but it suggested separate generic status of two Megaderma species. However, additional genetic data are necessary to resolve the phylogeny of Megadermatidae, a group that probably evolved by simultaneous divergence of all five extant lineages.

First record of Cimex pipistrelli (Cimicidae) in Slovakia

The family Cimicidae includes obligatorily somatic ectoparasitic forms of bugs which parasitize on warm-blooded vertebrates. The taxonomic position of the Cimex genus in the Palaearctic region has not been clarified and especially the data on the species group Cimex pipistrelli Jenyns, 1839 are chaotic. Already POVOLNÝ (1957) was of the opinion that the species Cimex dissimilis Horváth, 1910, C. stadleri Horváth, 1955 and C. singeri China, 1938 are synonyms of C. pipistrelli and are distributed in Great Britain, France, Belgium, the Netherlands, Hungary, Switzeland, Czechoslovakia, Poland, Russia, Byelorussia and Ukraine. USINGER (1966), in his monograph, distinguished seven bug species from the Palearctic region parasitizing on bats, viz. C. pipistrelli (Great Britain), C. dissimilis (Hungary, Germany), C. stadleri (Germany, Czechoslovakia), C. cavernicola Usinger, 1966 (Turkmenia), C. japonicus Usinger, 1966 (Japan), C. flavifuscus Wendt, 1939 (East China) and C. burmanus Usinger, 1966 (Burma). However, USINGER (1966) himself noted that this species group was less investigated than the Nearctic congeners from the group of C. pilosellus Horváth, 1910. In PÉRICART’S (1972) opinion there were not more species in West Europe than two, namely C. pipistrelli and C. dissimilis (= C. stadleri). The typical species C. pipistrelli occurs in the Netherlands. The bugs from the bats from Sweden, European part of the former USSR, Kazakhstan and C Asia represent, according to PÉRICART (1972), transitional forms between both W European species. Incorrectly, he gave the occurrence of C. dissimilis from Slovakia, as the site – surroundings of Brno – lays in S Moravia (Czech Republic). Later PÉRICART (1996) also mentioned the occurrence of C. pipistrelli from England, Ireland and Germany and with a question mark, from Sweden. According to KERZHNER (1989), the differences between species presented in the identification key and in the comparing text were partly contradictory and contained more discrepancies in the species descriptions. KERZHNER (1989) compared a material of bugs from the Zoological Institute in Sankt Petersburg and stated that all characters used by USINGER (1966) were highly variable and due to it they did not allow a reliable identification. KERZHNER supposed that all bugs from the Palaearctic region were to be considered as C. pipistrelli until more detailed investigation would be done. On the base of present knowledge, MORKEL (1999) included three species (C. dissimilis, C. stadleri C. pipistrelli) into the group of C. pipistrelli. MELBE (1999) published a simultaneous finding of C. dissimilis and C. pipistrelli from one site in Germany. The occurrence of two individuals of C. pipistrelli from Nyctalus leisleri (Kuhl, 1817) was published byWALTER (2004). However, some specimens of C. dissimilis examined by him had a long pubescence, while others had a short pubescence. The bug C. pipistrelli is a typical ectoparasite of bats. In Europe it was recorded first of all on the bats Nyctalus leisleri, N. noctula (Schreber, 1774) and Pipistrellus pipistrellus (Schreber, 1774). Our findings are the first records of the occurrence of C. pipistrelli in Slovakia.

Structure of tree vegetation may reduce costs of territory defence in Eurasian Nuthatch Sitta europaea

Capsule In pastured old oak woodland, breeding pairs of Eurasian Nuthatch selected territories with significantly higher densities of trees and cavities. Aims To define territorial borders that exist within a nuthatch population and to compare densities of trees and cavities between used and non-used parts of their available habitat in order to determine habitat preferences. Methods The number and location of territories was estimated by mapping the individual positions of colour-ringed birds. We measured habitat characteristics in regular sampling grid (number of trees and number of cavities per 50 × 50 m) during three successive seasons and modelled probability of occurrence of nuthatch territories in the area. Results Breeding pairs were observed to defend territories of median size between 1.46 and 2.93 ha. These sizes correspond well to high-quality habitat territories for this species. We found that pairs tended to occupy territories with higher densities of trees and cavities. Based on generalized linear mixed-effects model estimates, we found that in pastured oak woodland habitat with density of 60 trees per ha, the estimated probability of occurrence (with 95% confidence interval) of a nuthatch territory was about 96% (83−99). For cavity density, the probability of territory occurrence was about 74% (52−89) at the level of 60 cavities per ha. Conclusion We suggest that higher tree and cavity densities reduce territory defence costs in the species because birds may use less energy during foraging, predation avoidance and competition for a nest hole.