Zoltán Korsós

Snakebites in Hungary--epidemiological and clinical aspects over the past 36 years.

Epidemiological and clinical aspects of snakebites in Hungary between 1970 and 2006 were surveyed. A total of 97 cases were recorded from 21 species, including the two native vipers, Vipera berus and Vipera ursinii, and various exotic species represented by Viperidae, Elapidae, and Colubridae. Bites by native species on laymen are uncommon (17 cases) and present trivial clinical manifestations. Compared with the consequences of native Vipera cases, bites by exotic species often resulted in severe or life-threatening envenomations. These cases were treated with antivenom administration, plasmapheresis, fasciotomy, and amputation. There were two fatalities caused by V. berus and Agkistrodon contortrix. Both of these cases were inflicted in snake-handlers with a previous history of Viperidae bites and the cause of deaths are attributed to anaphylactic reactions as a consequence of hypersensitivity to the venom. Snake-handlers and their physicians face a major challenge due to the diversity and severity of signs and symptoms following exotic venomous snakebites, and the risk of anaphylaxis or anaphylactoid reactions in patients with repeated exposure to snake venom and antivenom. Highly dangerous venomous snake species continue to appear in collections of Hungarian snake-handlers.

Life history, population characteristics and conservation of the Hungarian meadow viper ( Vipera ursinii rakosiensis )

During a continuous population study of Vipera ursinii rakosiensis , 79 specimens were measured in the field, between 1993 and 1997. Body length and body mass of six juveniles were compared to those of 43 more specimens which were kept during their first winter in terraria. Significant differences were found in favour of the juveniles kept in captivity, whereas a comparison with earlier data from 1953 showed a strong decline in juvenile body mass. Based on body size, three age classes could be distinguished in the study population. The annual activity and reproductive cycle of the Hungarian meadow viper is described for the first time. A comparison to other European populations of Orsini′s viper revealed a remarkably higher clutch size in Vipera ursinii rakosiensis , which is explained by the larger body size of females in the particular population.

Asymmetry and population characteristics in dice snakes (Natrix tessellata): An interpopulation comparison

Three main types of asymmetry in bilateral characters were early separated (Van Valen, 1962). Directional asymmetry in a character means a consistent bias towards always the same side as opposed to the other, whereas antisymmetry is a consistent asymmetry in a bilateral character pair where the enlarged side occurs by chance. Both directional asymmetry and antisymmetry result from normal development. Fluctuating asymmetry (FA), that is nondirectional deviation from perfect symmetry, occurs when normal development is perturbed (Palmer and Strobeck, 1986; Leary and Allendorf, 1989). These perturbances can include habitat degradation (Sarre, 1996), pollution (Bengtsson et al., 1985), hybridisation (Graham and Felley, 1985), inbreeding (Roldan et al., 1998), small population size (Hutchinson and Cheverud, 1995), and the marginal distribution of a certain population (Møller, 1995; Siikamäki and Lammi, 1998). FA was thought to be a useful tool in conservation biology indicating the level of developmental instability that results from genetic and/or environmental stresses (Parsons, 1992; Clarke, 1995). However, the concept of FA, its connection with developmental instability, its heritability, its effect

Setting priorities for the conservation of terrestrial vertebrates in Hungary

The first step towards the preservation of endangered species is to establish an appropriate ranking system, which assigns different nature conservation priority scores to different taxa. The system developed by Millsap et al. (Wildlife Monograph 1990, 111: 1–57) has been modified and applied to the mammal, bird, reptile, and amphibian species of Hungary. Three variable groups have been compiled, including eight (measuring biological characteristics), three (features of the Hungarian population) and five (evaluation of research and conservation actions) variables, respectively. In cooperation with several experts, we gave scores to all 379 taxa considered. The most endangered taxon proved to be the Hungarian Meadow Viper (Vipera ursinii rakosiensis), which occurs only in Hungary with just a few hundred individuals. The species rank depends on the availability and quality of data, so it is urgent to devote more effort to survey and monitoring projects. We present a possible application of the species list, where the taxa are grouped according to their legal status in Hungary (strictly protected, protected, partly protected and not protected), and the validity of this categorisation was tested by applying multivariate discriminant analysis. Only 58.36% of the species were correctly classified. The reasons for stronger than expected protection include popularity, attractiveness, and local rarity, while reasons for lower protection include preference for hunting and control of predators and pests.

Size-dependent heating rates determine the spatial and temporal distribution of small-bodied lizards

The rate of heat exchange with the environment is of obvious importance in determining the time budget of behavioural thermoregulation in ectotherms. In small reptiles, heating rate depends mainly on their physical characteristics. We analysed the effect of body size, and the possible joint effects originating from shape and colour differences on heating rate in three small-bodied (0.15-20 g) sympatric lizard species. Heating rate was strongly influenced by body size, while no joint effects with the two other factors were detected. We found that the increase in heating rate with decreasing body size accelerated dramatically below a body weight of 2-3 g. We also analysed associations between body size, seasonal activity patterns and thermal characteristics of the sites where lizards were encountered in the field. Differently sized lizards occurred in thermally different sites and differed in their seasonal activity patterns, both within and among species. Smaller (<2-3 g) lizards occurred in cooler sites and exhibited very low activity during summer. Our results suggest that body size has a considerable influence on the spatial and temporal distribution of extremely small lizards in environments subject to a danger of overheating.

Tail loss and thermoregulation in the common lizard Zootoca vivipara

Tail autotomy in lizards is an adaptive strategy that has evolved to reduce the risk of predation. Since tail loss reduces body mass and moving ability—which in turn are expected to influence thermal balance—there is potential for a trade-off between tail autotomy and thermoregulation. To test this hypothesis, we studied a common lizard (Zootoca vivipara) population at high latitude, inhabiting a high-cost thermal environment. Z. vivipara is a small, non-territorial lizard known as a very accurate thermoregulator. We made two predictions: (1) the reduced body weight due to tail loss results in faster heating rate (a benefit), and (2) the reduction in locomotor ability after tail loss induces a shift to the use of thermally poorer microhabitats (a cost), thus decreasing the field body temperatures of active lizards. We did not find any effect of tail loss on heating rate in laboratory experiments conducted under different thermal conditions. Likewise, no significant relationship between tail condition and field body temperatures, or between tail condition and thermal microhabitat use, were detected. Thus, our results suggest that tail autotomy does not influence the accuracy of thermoregulation in small-bodied lizards.

Morphological analysis of two Hungarian water frog (Rana lessonae-esculenta) populations

Two water frog populations, Rana lessonae-esculenta systems, have been studied in Hungary from the morphological point of view. Multivariate analyses of selected morphological measurements based on biochemical identification of the species provide two ratios as possible key characters for determination of the two forms.

Phylogeography of the Caspian whipsnake in Europe with emphasis on the westernmost populations

The Caspian whipsnake (Squamata: Serpentes: Dolichophis caspius) reaches its northwestern distribution limit in Hungary where it is the single representative of its genus. Recently, several new localities of the species were discovered in Hungary. Focusing on these edge populations and on other ones in the western parts of the distribution, a phylogeographic study based on cytochrome b sequences was carried out. Thereby, a clear mitochondrial divergence was observed in Europe, with eastern and western haplotype groups found by analysing a number of specimens and populations. Our haplotype network analysis suggests a rather rapid postglacial (re)colonization of Europe by this snake species. In Hungary, three different haplotypes were detected.

First record of Vipera ursinii graeca in Albania (Reptilia: Serpentes, Viperidae)

In the framework of the botanical and zoological expeditions of the Hun - garian Natural History Museum to the Balkans, a specimen of Vipera ursinii graeca was observed in the southern Nemercke Mountains of Albania. It is the first record of the subspecies outside Greece, but zoogeographically it belongs to the northern Pin -

Calculation of Fluctuating Asymmetry of the biggest Caspian whipsnake population in Hungary compared to a common snake species

The Fluctuating Asymmetry (FA) is a special type of asymmetry in the populations of bilaterally symmetrical creatures. The FA gives us numerical data on the developmental instability of the populations and refers to potential genetical and environmental stressors affecting the populations. Here we give the first data on the FA of the protected Caspian whipsnake (Hierophis caspius) from Hungary. The FA indices of the biggest population from Villány Mts were compared to the FA indices of two differently stressed Dice snake (Natrix tessellata) populations [stressed (Mád) and seminatural (Lake Balaton)]. Based on the values of the multiple and the simple indices derived from sublabial scales, we can say that the status quo of the highly protected Caspian whipsnake population does not represent significant deviation from the near-natural dice snake population from the Lake Balaton.