Demography of a Eurasian lynx (Lynx lynx) population within a strictly protected area in Central Europe

Large carnivores promote crucial ecosystem processes but are increasingly threatened by human persecution and habitat destruction. Successful conservation of this guild requires information on long-term population dynamics obtained through demographic surveys. We used camera traps to monitor Eurasian lynx between 2009 and 2018 in a strictly protected area in the Bohemian Forest Ecosystem, located in the core of the distribution of the Bohemian–Bavarian–Austrian lynx population. Thereby, we estimated sex-specific demographic parameters using spatial capture–recapture (SCR) models. Over 48,677 trap nights, we detected 65 unique lynx individuals. Density increased from 0.69 to 1.33 and from 1.09 to 2.35 individuals/100 km2 for open and closed population SCR models, respectively, with corresponding positive population growth rates (mean = 1.06). Estimated yearly sex-specific survival probabilities for the entire monitoring period were high (females 82%, males 90%) and per capita recruitment rate was low (females 12%, males 9%), indicating a low yearly population turnover. We ascertained an average number of recruits of 1.97 and a generation time of 2.64 years when considering resident reproducing females. We confirmed that reproduction in the study area took place successfully every year. Despite the overall increase in local lynx densities, the number of detected family groups remained constant throughout the study period. These results indicated that the strictly protected study area acts as a source for the multi-use landscapes in its surroundings. In this first open population SCR study on lynx, we provide sex-specific demographic parameters that are fundamental information for lynx management in the study area as well as in similar contexts Europe-wide.


Supplementary Figure S2
Map of the camera trapping sites in the study area in the session 2010 with 18'000 km 2 continuous rectangular buffer used for closed population SCR analysis. The map was created using R 4.0.3 1 https://www.R-project.org/.

Supplementary Figure S3
Map of the camera trapping sites in the study area in the session 2011 with 18'000 km 2 continuous rectangular buffer used for closed population SCR analysis. The map was created using R 4.0.3 1 https://www.R-project.org/.
Supplementary Figure S4 Map of the camera trapping sites in the study area in the session 2012 with 18'000 km 2 continuous rectangular buffer used for closed population SCR analysis. In this case, camera traps were not active in the SNP. The map was created using R 4.0.3 1 https://www.R-project.org/.

Supplementary Figure S5
Map of the camera trapping sites in the study area in the session 2013 with 18'000 km 2 continuous rectangular buffer used for closed population SCR analysis. The map was created using R 4.0.3 1 https://www.R-project.org/.

Supplementary Figure S6
Map of the camera trapping sites in the study area in the session 2014 with 18'000 km 2 continuous rectangular buffer used for closed population SCR analysis. The map was created using R 4.0.3 1 https://www.R-project.org/.

Supplementary Figure S7
Map of the camera trapping sites in the study area in the session 2015 with 18'000 km 2 continuous rectangular buffer used for closed population SCR analysis. The map was created using R 4.0.3 1 https://www.R-project.org/.

Supplementary Figure S8
Map of the camera trapping sites in the study area in the session 2016 with 18'000 km 2 continuous rectangular buffer used for closed population SCR analysis. The map was created using R 4.0.3 1 https://www.R-project.org/.

Supplementary Figure S9
Map of the camera trapping sites in the study area in the session 2017 with 18'000 km 2 continuous rectangular buffer used for closed population SCR analysis. The map was created using R 4.0.3 1 https://www.R-project.org/.
Supplementary Figure S10 Map of the camera trapping sites in the study area in the session 2018 with 18'000 km 2 continuous rectangular buffer used for closed population SCR analysis. The map was created using R 4.0.3 1 https://www.R-project.org/.

Supplementary Figure S11
Age distribution pyramid of all detected lynx individuals with known age and sex (n = 24 out of 65; 9 males and 15 females). Age classes range from 1 to 10 (i.e. from 1-year-old individuals to 10 years old individuals). Gelman-Rubin diagnostic statistics of the demographic parameters including point estimates and upper limit of the 95% CI. M and m indicate parameters estimated for males while F and f indicate those estimated for females. The parameter "lam0" refers to baseline detection probability g0, "sigma" refers to the detection function scale , "gamma" refers to per capita recruitment rate, "phi" refers to survival probabilities, "N" refers to abundance, "sigma_t" refers to movement and "psex" indicates the probability of any individual being a female.  Table S3 Estimates and 95% confidence intervals (CI) of closed spatial capture-recapture (SCR) models referring to male (M) and female (F) lynx baseline detection probability g0, detection function scale σ (m) and sex ratio.