Vladimír Hanzal

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.

Dogs are sensitive to small variations of the Earth’s magnetic field

IntroductionSeveral mammalian species spontaneously align their body axis with respect to the Earth’s magnetic field (MF) lines in diverse behavioral contexts. Magnetic alignment is a suitable paradigm to scan for the occurrence of magnetosensitivity across animal taxa with the heuristic potential to contribute to the understanding of the mechanism of magnetoreception and identify further functions of magnetosensation apart from navigation. With this in mind we searched for signs of magnetic alignment in dogs. We measured the direction of the body axis in 70 dogs of 37 breeds during defecation (1,893 observations) and urination (5,582 observations) over a two-year period. After complete sampling, we sorted the data according to the geomagnetic conditions prevailing during the respective sampling periods. Relative declination and intensity changes of the MF during the respective dog walks were calculated from daily magnetograms. Directional preferences of dogs under different MF conditions were analyzed and tested by means of circular statistics.ResultsDogs preferred to excrete with the body being aligned along the North–South axis under calm MF conditions. This directional behavior was abolished under unstable MF. The best predictor of the behavioral switch was the rate of change in declination, i.e., polar orientation of the MF.ConclusionsIt is for the first time that (a) magnetic sensitivity was proved in dogs, (b) a measurable, predictable behavioral reaction upon natural MF fluctuations could be unambiguously proven in a mammal, and (c) high sensitivity to small changes in polarity, rather than in intensity, of MF was identified as biologically meaningful. Our findings open new horizons in magnetoreception research. Since the MF is calm in only about 20% of the daylight period, our findings might provide an explanation why many magnetoreception experiments were hardly replicable and why directional values of records in diverse observations are frequently compromised by scatter.

Magnetic Alignment in Carps: Evidence from the Czech Christmas Fish Market

While magnetoreception in birds has been studied intensively, the literature on magnetoreception in bony fish, and particularly in non-migratory fish, is quite scarce. We examined alignment of common carps (Cyprinus carpio) at traditional Christmas sale in the Czech Republic. The sample comprised measurements of the directional bearings in 14,537 individual fish, distributed among 80 large circular plastic tubs, at 25 localities in the Czech Republic, during 817 sampling sessions, on seven subsequent days in December 2011. We found that carps displayed a statistically highly significant spontaneous preference to align their bodies along the North-South axis. In the absence of any other common orientation cues which could explain this directional preference, we attribute the alignment of the fish to the geomagnetic field lines. It is apparent that the display of magnetic alignment is a simple experimental paradigm of great heuristic potential.

Directional compass preference for landing in water birds

IntroductionLanding flight in birds is demanding on visual control of velocity, distance to target, and slope of descent. Birds flying in flocks must also keep a common course of landing in order to avoid collisions. Whereas the wind direction may provide a cue for landing, the nature of the landing direction indicator under windless conditions has been unknown. We recorded and analysed landing directions of 3,338 flocks in 14 species of water birds in eight countries.ResultsWe show that the preferred landing direction, independently of the direction from which the birds have arrived, is along the north-south axis. We analysed the effect of the time of the year, time of the day (and thus sun position), weather (sunny versus overcast), light breeze, locality, latitude, and magnetic declination in 2,431 flocks of mallards (Anas platyrhynchos) and found no systematic effect of these factors upon the preferred direction of landing. We found that magnetic North was a better predictor for landing direction than geographic North.ConclusionsIn absence of any other common denominator determining the landing direction, the alignment with the magnetic field lines seems to be the most plausible if not the only explanation for the directional landing preference under windless and overcast conditions and we suggest that the magnetic field thus provides a landing direction indicator.

The first report on Cryptosporidium suis and Cryptosporidium pig genotype II in Eurasian wild boars (Sus scrofa) (Czech Republic)

A total of 193 faecal samples of adult Eurasian wild boars were collected at 12 enclosures across the Czech Republic and examined for Cryptosporidium infection using both microscopic and molecular tools. Cryptosporidium oocysts were not detected in any of the 193 faecal samples examined using the aniline-carbol-methyl violet staining method. Thirty-two positive cases of Cryptosporidium infection were detected using either genus- or species-specific nested PCR. Mono-infection with Cryptosporidium suis and Cryptosporidium pig genotype II were found in 13 and 7 cases, respectively. Five mixed infections of C. suis and Cryptosporidium pig genotype II were detected using PCR/RFLP with genus specific primers. The number of detected mixed infections increased 2.4 fold when a species-specific PCR was employed. No other Cryptosporidium spp. was detected. Unlike cryptosporidiosis of domestic pigs, C. suis was detected as a dominant species infecting adult Eurasian wild boars. There was no association between diarrhoea and the presence of Cryptosporidium infection in the Eurasian wild boars studied. This is the first report on the Cryptosporidium infection caused by C. suis and Cryptosporidium pig genotype II in Eurasian wild boars (Sus scrofa).

Cryptosporidium suis and Cryptosporidium scrofarum in Eurasian wild boars (Sus scrofa) in Central Europe.

From 2011 to 2012, to identify Cryptosporidium spp. occurrence in Eurasian wild boars (Sus scrofa) 29 randomly selected localities (both forest areas and enclosures) across the Central European countries of Austria, the Czech Republic, Poland, and the Slovak Republic were investigated. Cryptosporidium oocysts were microscopicaly detected in 11 out of 460 faecal samples examined using aniline-carbol-methyl violet staining. Sixty-one Cryptosporidium infections, including the 11 infections that were detected by microscopy, were detected using genus- or species-specific nested PCR amplification of SSU rDNA. This represents a 5.5 fold greater sensitivity for PCR relative to microscopy. Combining genus- and species-specific PCR tools significantly changes the perspective on the occurrence of Cryptosporidium spp. in wild boars. While RFLP and direct sequencing of genus specific PCR-amplified products revealed 56 C. suis (20) and C. scrofarum (36) monoinfections and only 5 mixed infections of these species, species-specific molecular tools showed 44 monoinfections and 17 mixed infections with these species. PCR analysis of the gp60 gene did not reveal any other Cryptosporidium infections. Similar to domestic pigs, C. scrofarum was detected as a dominant species infecting adult Eurasian wild boars (Sus scrofa). Cryptosporidium infected wild boars did not show signs of clinical disease. This report is perhaps the most comprehensive survey of cryptosporidial infection in wild boars.

Effect of habitat and game management practices on ring-necked pheasant harvest in the Czech Republic

The ring-necked pheasant (Phasianus colchicus L.) is one of the most popular small game species both numerically and economically. Pheasant populations are commonly managed in the Czech Republic in order to maximize their harvest. Game managers need to be aware of the possible effects of different management tools on wild pheasant populations. We used data from 38 hunting grounds collected over an 8-year period (2004–2011) and generalized linear mixed effects models (GLMMs) to assess whether pheasant harvest was related to the habitat characteristics and game management practices (release of hand-reared individuals and predator control) in the Czech Republic. The proportion of grasslands, idle lands (spontaneously set-aside lands), and organically farmed lands (i.e., with limited use of industrially made fertilizers and pesticides) and the density of watercourses were positively related to the pheasant harvest. The proportion of forests and road density showed a negative relationship with the pheasant harvest. An important effect of year on the pheasant harvest was also found. In terms of game management practices, predator control intensity (i.e., foxes, martens, corvids) was positively related to the pheasant harvest. The release of hand-reared individuals was not included in the final GLMMs. Our study suggests that the best long-term strategy to reinforce the wild population of ring-necked pheasants would be to concentrate on habitat improvement through the implementation of set-aside management, maintaining the right percentage of shrubby and grass vegetation, to continue with targeted predator control, and to reduce the costly practice of releasing of hand-reared individuals.

Effect of environmental factors and time of shooting on carcass weight of European roe deer (Capreolus capreolus L.).

Wpływ czynników przyrodniczych i terminu odstrzału na masę tuszy sarny europejskiej (Capreolus capreolus L.) Effect of environmental factors and time of shooting on carcass weight of European roe deer (Capreolus capreolus L.) The aim of the study was to characterize the carcass weight of the European roe deer shot during four hunting seasons (2001/2002 - 2004/2005) in five provinces of northern Poland. The total number of animals evaluated in all seasons was 43 818, including 18 205 bucks, 19 763 hinds and 5 850 fawns. The average carcass weight was respectively 16.6 kg, 16.5 kg and 11.2 kg. The heaviest animals were shot in the Provinces of Podlasie and Warmia & Mazury (eastern part of research area), whereas the lightest ones - in the Provinces of Western Pomerania and Pomerania (western part of research area). Higher carcass weight was recorded in the regions dominated by arable land and lower - in the regions dominated by forest. The body weight of bucks, hinds and fawns varies throughout the hunting season. The males reached the highest body weight in July, while the females and the young in December.

Carcass characteristics, meat quality, and fatty acid composition of wild-living mallards (Anas platyrhynchos L.)

Abstract The aim of this study was to determine the carcass characteristics, meat quality, and fatty acid composition of wild‐living mallards. The experimental materials comprised 30 mallards (1:1 sex ratio) harvested during the hunting season in northeastern Poland. The carcasses were transported to the laboratory where they were weighed individually, plucked, dressed, and dissected. The proximate chemical composition and physicochemical properties of meat and the fatty acid profile of breast muscle lipids were determined, and a histological analysis was performed. Body weight (BW) and carcass weight were higher in males than in females (P ≤ 0.05), whereas the percentage share of carcass tissue components was similar in both sexes. Edible components accounted for approximately 60% (♂) to 60.7% (♀) of the total BW of mallards, including lean meat; 40.9% (♂) to 41.5% (♀), skin with subcutaneous fat; 10.7% (♂) to 10.8% (♀), and giblets; 8.3% (♂) to 8.4% (♀). Breast muscles had high protein content (23.51%♀ to 23.6% ♂) and low fat content (0.82% ♂ to 0.84% ♀). In the fatty acid profile of breast muscle lipids, saturated fatty acids (SFA) accounted for 39.1% (♂) to 39.04% (♀), monounsaturated fatty acids (MUFA)—for 17.31% (♂) to 17.33% (♀) and polyunsaturated fatty acids (PUFA)—for 43.61% (♀) to 43.64% (♂). The diameters of type IIA and type IIB muscle fibers were lower in males than in females (P ≤ 0.05), whereas lipid storage sites in muscles were similar in both sexes. The values of cooking loss (CL), water‐holding capacity (WHC), pH24, and color parameters of breast meat were comparable in males and females. The results of this study indicate that wild‐living mallards, both males and females, are characterized by high meat quality, and that seasonal mallard harvests can provide meat with desirable eating attributes, attractive to consumers.

Host specificity and age-dependent resistance to Cryptosporidium avium infection in chickens, ducks and pheasants

Host- and age-specificity of Cryptosporidium avium were studied in 1-, 21- and 365-day-old chickens (Gallus gallus), domestic ducks (Anas platyrhynchos) and ring-necked pheasants (Phasianus colchicus) under experimental conditions. Cryptosporidium avium was not infectious for ring-necked pheasants, but it was infectious for ducks and chickens at all age categories. The course of infection in ducks did not differ among age categories, but 365-day-old chickens had less severe infections than 1- and 21-day-old chickens. The patent period in chickens and ducks was >30 DPI, but ducks started to shed oocysts of C. avium earlier (5-6 DPI) and at a lower intensity (accumulated value of infection intensity of 58,000-65,000 OPG) than chickens (9-11 DPI and accumulated value of infection intensity of 100,000-105,000 OPG). Experimentally infected birds showed no clinical signs of cryptosporidiosis.