We investigated the effect of multiple variables on the amplification success rate of microsatellite DNA extracted from faeces of wild Eurasian otters. The success rate was affected by (i) type of sample, with higher success rates in anal jelly samples than faeces, and (ii) temperature, with a negative effect of increased temperature at time of collection. To increase the effectiveness of microsatellite genotyping of otter faeces, we recommend collecting samples in cold months and early in the morning, preferably in a frozen state, and the collection of anal jelly samples, or the jelly part from faeces, whenever possible.

Successful conservation and management of rare and elusive species requires reliable estimates of population size, but acquisition of such data is often challenging. We compare the two most frequently used methods of assessing abundance of Eurasian otter (Lutra lutra) populations, noninvasive genetic sampling (NGS) based on genotyping of faeces and field surveys using snow tracking. In a 100-km 2 oligotrophic otter habitat with linear water bodies, both methods yielded very similar estimates (10-12 individuals). However, in a 100-km 2 fishpond area, consisting of a complex network of rivers, fishponds, channels and marshes, genotyping of faeces revealed the presence of a higher number of individuals (46-50 genotypes) than the snow survey (38 individuals). NGS data analysed by capture-mark-recapture (CMR)-based software CAPWIRE provided even higher estimates, being twice the number assessed through snow tracking (76-81 individuals, CI 95% = 49-96 and 55-89). Our results suggest that the performance of both NGS and snow tracking is comparable in simple linear habitats, but in complex habitats with very high otter density a combination of genetic and field methods, or CMR analysis using genetic data, is recommended. We emphasise that to obtain reliable estimates using NGS it is necessary to follow strict protocols for detection and elimination of genotyping errors. Based on a literature review and our experience, we suggest improvements that may increase the success rate and efficiency of NGS for otters.

Over the latter part of the 20th century, Eurasian otter Lutra lutra populations suffered dramatic declines, resulting in extinction or fragmentation of populations in many western and central European countries. Part of the Czech otter population became totally isolated while the Slovak population remained partly connected to the relatively continuous central and eastern European otter distribution range. This paper examines the genetic structure and past demographic history of otters in the Czech and Slovak Republics, using microsatellite nuclear markers amplified from DNA extracted from tissue and faecal samples. A relatively high level of genetic differentiation was found between the Czech and Slovak populations (F ST = 0.154, P = 0.0002), supported by a perfect assignment in Bayesian cluster analysis. Both the Czech and Slovak populations showed significant heterozygosity excess (assuming an infinite allele model), indicating recent population bottlenecks. A very recent population decline was also suggested by coalescent analysis, inferring a drop to c. 25% of past effective population size in both populations. The timing of the decline was in accordance with published data from otter surveys, suggesting that the strongest decline probably occurred between the 1970s and the mid-1990s. The results of this study confirm that otter populations remain vulnerable to any violent demographic change and, despite the claims of fish-farmers and anglers for legal culls, it is highly desirable that they remain a strongly protected species in both countries. The spreading and reconnection of otter populations observed recently is essential for the future health of the populations, and should be supported through habitat conservation.

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SummaryThe aim of our study was to analyze helminth status and to evaluate ecological conditions for infections of chamois with lung nematodes in national parks of Slovakia during global warming. The autopsies and larvoscopic examination of faeces collected from localities inhabited by Tatra chamois (Rupicapra rupicapra tatrica) in Tatra National Park (TANAP) and Low Tatras National Park (NAPANT) revealed the presence of following protostrongylids: Muellerius capillaris, Neostrongylus linearis and the specific chamois species Muellerius tenuispiculatus. Same species of lung nematodes were found in introduced chamois of Alpine origin (Rupicapra rupicapra rupicapra) in the Slovak National Park Veľká Fatra (NAPVF) and the Slovak Paradise National Park (NAPSR), and in the latter park also geohelminth Dictyocaulus viviparus was sporadically determined. The mean prevalence of lung nematodes in individual parks varied from 70.9 to 97.2 %. The mean number of L1 larvae per 1 g of faeces in Tatra chamois from TANAP in Belianske Tatras and in Alpine subspecies from NAPSR corresponded to a high level of infection (120.3 and 110.1, respectively). In other studied biotopes the mean number of L1 larvae (19.4 -42.5) revealed the moderate infection. Although no significant differences concerning levels of infection within the monitored years were observed, the level of infection during the summer was significantly lower than that during spring and autumn periods. The variety of snail species as the intermediate hosts of lung nematodes provide suitable conditions for the development of lung nematodes in the all studied Slovak National Parks. Global climatic changes have also likely contributed to an increase of infectivity rate.