Research reveals a high turnover and low survival rate of lynx in the Western Carpathians
9.12.2021, Selmy.cz
Extensive research on the lynx population at the periphery of the Western Carpathians was conducted between 2015 and 2020 by an international team of scientists, including Hnutí DUHA zoologists and fieldworkers. The team led by Martin Dula from the Institute of Forest Ecology at Mendel University in Brno focused on evaluating population trends and published their findings in spring 2021 in the prestigious scientific journal Scientific Reports [1]. The study helps to fill in the gaps in the existing knowledge of the Carpathian lynx population. Among other things, it is the first to present multi-seasonal population dynamics data.
The Carpathian population became a source for successful lynx reintroductions to many areas in Europe. Now, we need to obtain accurate data on the state of the native population to protect it effectively.
Several lynx populations in Europe were restored as part of reintroduction programmes between 1970 and 1990 when wild lynx from the Carpathians were relocated to selected regions. In addition, more animals are currently being captured in the Carpathians to reinforce lynx projects in Dinaric Mts., Slovenia and Palatine Forest, Germany. The overall status of the source population is based mainly on rough national estimates that have been challenged by several local studies as having been overestimated. This highlights the necessity to obtain robust demographic data on the native Carpathian population, which is essential for their effective conservation.
Experts have spent five years studying the lynx population on the periphery of the Western Carpathians
The research was based on camera trap monitoring in three study areas: Beskydy, Javorníky and Kysuce. In all three areas, the landscape is intensively used by humans. The individual mountain units are separated by densely populated valleys and river basins with developed infrastructure. The researchers set out to evaluate the lynx population dynamics and obtain other demographic data, such as survival and individual’s turnover rate during five consecutive seasons.
Research of the lynx population in the Western Carpathians was based on camera trap monitoring; source: Friends of the Earth Czech Republic (Hnutí DUHA Olomouc)
Population density fluctuated strongly in all areas
Over the five consecutive seasons, camera traps captured 53 individual lynx in all three areas. Of the total number, there were 29 males, 18 females and 6 lynx whose sex remained undetermined. Population density fluctuated strongly in all research sites. The average annual density for all three sites was estimated to range from 0.69 to 1.20 lynx per 100 km2 of suitable habitat. Each year, the highest values were recorded in the Slovak Kysuce. On average, the population density in Kysuce was 2.5 times higher than in the Beskydy Mountains, although the Beskydy area provides a similar proportion of suitable habitat that is not fully used by lynx. The authors attribute these results mainly to the proximity of the Kysuce site to the core of the Western Carpathian lynx population. Based on the findings, the total number of lynx in Slovakia was estimated at 193 to 337 individuals. The estimate confirms the conclusions of an earlier Slovak study that the lynx population numbers in Slovakia officially reported by the State Nature Conservancy to the European Commission were overestimated (300–400 individuals were reported between 2013–2018).
Over the five consecutive seasons, camera traps captured 53 individual lynx in all three areas. Of the total number, there were 29 males, 18 females and 6 lynx whose sex remained undetermined. The picture shows the leading female Heřmína; source: Friends of the Earth Czech Republic (Hnutí DUHA Olomouc)
Lynx population in the Western Carpathians is likely limited by strong anthropogenic pressures, mainly road mortality and poaching
Over the five years, researchers found a relatively low survival rate and, conversely, a high individual’s turnover (on average about 46%). Only three individuals were documented over the five consecutive seasons. This cannot be explained by the typical behaviour of lynx as studies have previously demonstrated their long-term territorial fidelity. The findings also point to weak but consistent links between lynx subpopulations in the Beskydy, Javorníky and Kysuce areas.
Only three individual lynx were documented over the five consecutive seasons, one of them was a male named Martin; source: Friends of the Earth Czech Republic (Hnutí DUHA Olomouc)
Fluctuating population densities, which varied up to several times among seasons in all study areas, relatively low survival and high turnover rates may have been influenced by several ecological factors, such as food availability, diseases or intra-species competition. However, population numbers of wild ungulates are at historical maximums in Slovakia and the Czech Republic. Therefore, it is unlikely that the lynx population has been negatively affected by the lack of natural prey. In all five seasons, the researchers did not observe any signs of a disease outbreak in the study area, and lynx did not use all suitable habitats, which was most evident in the Beskydy model site.
Therefore, the authors conclude that the elusive carnivores are exposed to a strong anthropogenic pressure also documented in other areas of the Western Carpathians and throughout Europe. Collisions of lynx with road traffic or trains, poaching and orphaned kittens are regularly documented in the study areas [3]. Poaching, as well as habitat loss from landscape fragmentation and an increasing number of lynx-vehicle collisions, seem to be the most limiting factors restricting population growth and dispersion of lynx to the areas where they have been extinct in the past. In the future, these factors might negatively influence the currently favourable conservation status of the Western Carpathian lynx population. Conservationists are therefore calling for a more rigorous investigation of illegal killings, as well as addressing the problem of increasing migration barriers [4].
Notes:
[1] Martin Duľa, Michal Bojda, Delphine B. H. Chabanne, Peter Drengubiak, Ľuboslav Hrdý, Jarmila Krojerová-Prokešová, Jakub Kubala, Jiří Labuda, Leona Marčáková, Teresa Oliveira, Peter Smolko, Martin Váňa & Miroslav Kutal, 2021: Multi-seasonal systematic camera-trapping reveals fluctuating densities and high turnover rates of Carpathian lynx on the western edge of its native range. Scientific Reports 11: 9236.
[2] Each season comprised of an 80-day winter period from November to February between 2015 and 2020.
[3] See for example:
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http://www.carnivores.cz/articles/a-dead-lynx-found-on-the-highway-near-brno/
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https://www.selmy.cz/tiskove-zpravy/letos-prisly-v-beskydech-o-zivot-jiz-dve-rysice/
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http://www.carnivores.cz/articles/a-lynx-cub-hit-by-a-car-in-vsetin-region/
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https://www.selmy.cz/clanky/nalez-uhynuleho-rysa-ostrovida-v-chko-beskydy/
[4] In the Beskydy Mountains, the international SaveGREEN project is now also focusing on the issue of migration barriers. The project aims to promote the best solution for the protection of ecological corridors in 8 pilot areas, including the Beskydy-Kysuce area on the Czech-Slovak border. The project is co-funded by European Union funds (ERDF). More information is available on the website www.interreg-danube.eu/SaveGREEN or in Czech at www.selmy.cz.
ANNA ŘEZNÍČKOVÁ
