ACTA BIOLOGICA SLOVENICA LJUBLJANA 2012 Vol. 55, Št. 2: 49-63 ABS Status and distribution of Eurasian lynx (Lynx lynx) in Slovenia from 2005 to 2009 Stanje in razširjenost evrazijskega risa (Lynx lynx) v Sloveniji v obdobju 2005-2009 Ivan Kos a*, Iztok Korenb, Hubert Potočnika, Miha Krofela a Biotechnical Faculty, Department of Biology, Večna pot 111, 1000 Ljubljana, Slovenia b Slovenia Forest Service, OE Tolmin, Tumov drevored 17, 5220 Tolmin, Slovenia ^correspondence: ivan.kos@bf.uni-lj.si Abstract: In Slovenia, the status of the re-introduced Eurasian lynx population is monitored using the SCALP (Status and Conservation of Alpine Lynx Populations) methodology. Monitoring is organized by the Slovenia Forest Service in cooperation with other institutions and individuals. We analysed the data for the 2005-2009 monitoring period and compared it with the previous periods to explore population status and trends for the northern part of the Dinaric population. During this last pentad we recorded six C1 category data points, 832 data points of category C2, and 96 points of category C3. These numbers are comparable to the previously reported period of 2000-2004. The spatial distribution of signs of lynx presence remained similar compared to the previous period. Presence and status of the lynx are easier to interpret because of additional telemetry data and a habitat suitability that has been produced since the last report. We assume that this lynx population is critically endangered, because of demographic as well as genetic reasons. To prevent local extinction, an active approach is needed for revitalization of the population which would address demographic factors as well as improve the depleted gene pool. Keywords: Eurasian lynx, Lynx lynx, Dinaric population, monitoring, distribution, Slovenia. Izvleček: V Sloveniji poteka monitoring prisotnosti introducirane populacije evrazijskega risa na osnovi SCALP metodologije v organizaciji Zavoda za Gozdove Slovenije ob sodelovanju drugih inštitucij in posameznikov. Z analizo podatkov in primerjavo s preteklimi obdobji podajamo stanje in trend severnega dela dinarske populacije. V petletnem obdobju 2005-2009 je bilo zabeleženih 6 podatkov C1; 832 C2 in 96 C3 kategorije, kar je podobno kot v preteklem obdobju 2000-2004. Tudi prostorsko so podatki podobno razporejeni po Sloveniji. Predstava o prisotnosti in statusu risa se dopolnjuje s podatki radiotelemetričnega spremljanja in modelom primernega prostora, ki je bil izdelan v zadnjem petletnem obdobju. Predvidevamo, da je populacija kritično ogrožena tako zaradi demografskih kakor tudi genetskih razlogov. Za uspešno varstvo bo treba aktivno pristopiti k revitalizaciji populacije tako s popolnjevanjem in varovanjem demografske in spolne strukture kakor tudi reševanjem osiromašenega genskega sklada. Ključne besede: Evrazijski ris, Lynx lynx, dinarska populacija, monitoring, razširjenost, Slovenija. Introduction Eurasian lynx (Lynx lynx) was exterminated in Slovenia in the early 20th century. The current population originates from a 1973 reintroduction, when three pairs of animals have been released from quarantine enclosures. These animals were captured for reintroduction in Rudogorje (Slovakia). The newly established population showed incredible dynamics of population growth and spatial expansion (Čop 1994). Relatively intensive hunting was introduced already in 1978 as a part of the population management. Lynx hunting reached its peak in 1990 when 13 animals were legally shot in Slovenia (Kos et al. 2004, Potočnik et al. 2009). The lynx now present in Slovenia belong to the north-western part of the Dinaric population, which is sometimes considered to be divided into Dinaric and Alpine subpopulations (Koren et al. 2006). It is a part of the population that extends to the south-eastern Alps and presents an important source for potential recolonization of the Alps from East. It is therefore crucial for establishment of the potential future pan-Alpine metapopulation. The southern (Dinaric) and northern (Alpine) subpopulations are separated by Ljubljana-Koper highway and additionally by areas of unsuitable habitat (Skrbinšek 2004). Therefore it is important to maintain the connectivity between the subpopulations and adapt conservation efforts accordingly. Since the reintroduction, there was a considerable effort applied in intensive monitoring of signs of presence and registration of all detected lynx mortalities (Čop 1994, Čop and Frković 1998, Staniša et al. 2001, Koren et al. 2006). However, the estimations of population size that followed were based on misunderstood, often anecdotal data, lack of knowledge and individual (often erroneous) opinions of individual managers, which caused considerable overestimations of the population size with estimates of up to 200 animals (data Slovenian Hunting Association, State's Hunting Grounds, unpublished). These estimates were the basis for approval of high hunting quotas, and possibly also a promoter of illegal killings, especially after the protection of lynx in 1993 when only exceptional harvest was allowed based on the decision of the competent minister. Systematic, science-based, fine-scale monitoring is a prerequisite for successful conservation, especially if it includes management actions such as hunting, as well as for establishing positive attitudes of different interest groups (Treves 2009, Treves and Naughton - Treves 1999). Uncertainty in population size estimates can cause extinctions in exploited lynx populations (Saether et al. 2010). Lynx monitoring frequently includes high proportion of uncertain data that can give biased results on distribution and abundances (Molinari-Jobin et al. 2012a). Lynx habitat in Slovenia is fragmented into several habitat patches (Skrbinšek 2004). With exception of Snežnik-Javorniki and Kočevje forest habitat patches, other areas are fragmented by linear barriers or agricultural/urban landscape, with fragments that are frequently the size of only a single average lynx territory, or even smaller. Dispersal and distribution of lynx in such fragmented landscape is very unpredictable. Habitat fragmentation can have considerable effect on occupancy of the patches as well as on adequate sex structure within the patches (Niedzialkowska et al. 2006, Molinari-Jobin et al. 2010, Samelius et al. 2011). Only through systematic and intensive recording of signs of lynx presence categorized according to reliability we can track dynamics and spatial pattern of lynx distribution (Molinari-Jobin et al. 2012a,b). In this paper we present the results of the monitoring of signs of lynx presence and determination of Dinaric lynx population status in Slovenia between 2005 and 2009. Methods Data collection Data on signs of lynx presence have been collected following methodology described by Koren et al. (2006). Data on signs of lynx presence, dead lynx and attacks on domestic animals have been continuously recorded since the population was established population in 1973 (Čop 1994). Since 1994 lynx monitoring has been coordinated by Slovenia Forest Service (SFS) (Staniša 2001, Jonozovič 2004, Koren et al. 2006,). The data are classified into three reliability levels in accordance with the SCALP guidelines (Molinari-Jobin et al. 2012a) and the possibility to verify the collected data: C1: Confirmed "hard facts", verified and undisputable records of lynx presence such as (1) dead lynx, (2) live captured lynx, (3) good-quality and geo-referenced lynx photos (e.g., from camera traps), and (4) samples (e.g. excrements, hair) attributed to lynx by means of scientifically reliable analyses, such as genetic analysis. C2: Records confirmed by a lynx expert (e.g. trained member of the SFS or Slovenian Hunting Society) such as (1) killed livestock or (2) wild prey, and (3) lynx tracks or other assessable signs of lynx presence. C3: Unconfirmed category: observations (kills, tracks, other signs of lynx presence too old or not thoroughly documented, but with description indicating lynx presence) and all unverified observations such as sightings and vocalizations. Research activities were intensified during the 2005-2009 period with live capturing of lynx, GPS telemetry, monitoring of lynx using hair-traps and photo-traps, prey analysis and habitat and population modelling (Potočnik 2004, Skrbinšek 2004, Krofel 2006, Krofel et al. 2006, Krofel 2008, Skrbinšek and Krofel 2008, Potočnik et al. 2009, Kos et al. 2011, Krofel et al. 2012). Some of these data, particularly from Snežnik-Javorniki area are also included in the report. All reported damages on domestic animals have been inspected by authorized SFS personnel. Data analysis All recorded data of lynx signs of presence were entered into the monitoring databases, kept and analy sed at the regional unit of SFS in Tolmin. The number of lynx presence data according to their category, including mortality data and damages attributed to lynx, were graphically presented and compared to previous pentads. Lynx population ranges for particular pentads were calculated using geo-referenced lynx presence data of all three categories and fixed kernels, using least square cross-validation (LSCV) approach at 50, 75 and 90% probability area, were prepared (ESRI, ArcGIS 10.0). Results Monitoring of lynx distribution During the 15-year period of collecting and recording signs of lynx presence, coordinated by SFS, 2357 records have been collected according to the SCALP methodology. The number of recorded data have been increasing over the pentads (1995-99: 505; 2000-04: 908; 2005-09: 944). The increase is mainly due to an increasing proportion of C2 data (Tab. 1 ). Majority of the data (71%) were collected in the southern (Dinaric) subpopulation, others in northern (Alpine) subpopulation. During the last pentad (2005-09) the number of signs of lynx presence has been constantly decreasing from 249 in 2005 to 158 in 2009 (Fig. 1). The decline is most pronounced for C2 data (Fig. 2). In the last pentad there were seven C1 data from photographed or collared lynx and nine data from non-invasive genetic samples (scats, urine, hair), collected during that period. The majority of C1 data from the previous periods referred to killed (shot) lynx. On the other hand, during our study period no dead lynx were reliably recorded (Fig. 3). In State's Hunting Reserves (LPNs) that are managed by SFS, daily monitoring of large carnivores has been implemented since 1991. Among them, the highest number of signs of lynx presence during the last pentad was recorded in LPN Jelen (278 km2), however there has been substantial decline in the last three years (Fig. 4). Similarly, in LPN Medved (379 km2) the number of records was low compared to the previous periods (Fig. 4). In other LPNs such intensive monitoring was started in 2008. Distribution of lynx presence In Slovenia, lynx are present in two areas: (1) Alpine area and (2) Dinaric area. - Sporadic and mostly unconfirmed (C3) data have been reported also from Kamnik-Savinja Alps in the north of Slovenia. In the last three pentads we did not observe any major change in the range where signs of lynx presence have been recorded. Lynx population ranges (95% fixed kernel) over pentads were 5820, 6270 and 5530 km2 (Figs. 5-7). The concentrations of the signs remained more or less constant Data category Southern subpopulation Northern subpopulation Total/country 1995 -1999 2000 -2004 2005 -2009 1995 -1999 2000 -2004 2005 -2009 1995 -1999 2000 -2004 2005 -2009 C1 12 7 6 1 0 13 7 16 C2 230 674 770 77 93 62 307 767 832 C3 61 48 7 124 86 89 185 134 96 Total/period 303 729 783 202 179 151 505 908 944 Table 1: Number of data of lynx presence by different SCALP categories. Tabela 1: Število znakov prisotnosti risa po različnih SCALP kategorijah. 1000 900 Z 800 ш o z 700 ш w £ 600 Q. O 500 w СЭ 400 t/j z 300 S 200 100 -0 -I—I-1—,—I-—,—-—,—I-1—,—I-—,—I-—,—I-Ц—I-Ц 95 - 99 00 - 04 2005 2006 2007 2008 2009 05 - 09 PENTADS / YEARS Figure 1: Dynamics of recorded lynx presence data over the pentads between 1995-2009. Lynx presence data in the last pentad - white bars. Slika 1: Dinamika vseh podatkov monitoringa med petletnimi obdobji v letih 1995-2009. Podatki monitoringa v zadnjem petletnem obdobju - beli stolpci. only in the area of the Snežnik plateau, whereas in the other areas signs have declined. In the last pentad, compared to the previous monitoring periods, substantial decline of the presence data was detected in south-eastern Slovenia (Kočevsko region) and in the Alps (Figs. 5-7). Damages attributed to lynx Inspected livestock damages attributed to lynx during the entire 15 year monitoring ranged between 2 (1996) and 34 (2001) cases and estimated annual value of damages ranged between 400 € and 35,800 € (Tab. 2). Number of reported cases of damages attributed to lynx in last pentad was smaller than in previous pentads and number of killed animals declined for more than 80% compared to the previous period (Tab. 2, Fig. 3). 900 800 — 700 ш О ш 600 (/) ш m О- 500 u. О g 400 £2 00 X 300 200 100 95 - 99 00 - 04 2005 2006 2007 PENTADS / YEARS 2008 2009 05 - 09 Figure 2: Dynamics of C2-category data collected over the pentads between 1995-2009. Lynx presence data for the last pentad - white bars. Slika 2: Dinamika zbiranja C2 podatkov med petletnimi obdobji v letih 1995-2009. Podatki monitoringa v zadnjem petletnem obdobju - beli stolpci. 0 Figure 3: Number of recorded lynx mortality (killed or found dead) in Slovenia from 1990 to 2009. Slika 3: Število zabeleženih mrtvih (odstreljenih ali drugače poginulih) risov v Sloveniji od 1990 do 2009. Discussion Continuous monitoring according to the SCALP methodology (Molinari-Jobin et al. 2012a) provides a basic insight into the lynx population in Slovenia. In the period 2005-2009 the distribution of signs of lynx presence indicates a similar distribution range as in the previous periods. However, the results also indicate that the population size is declining. It is shown that during the 15 years of monitoring the number and proportion of C2 category data was constantly increasing, while the number of C3 category data declined. Increasing number of experts from SFS and other institutions were getting involved in the lynx monitoring during this period. Also research projects on lynx with intensive field work in the last pentad additionally increased the monitoring effort. Thus the number of the monitoring data over the entire period is not reflecting the lynx population density; however the relative spatial distribution of the data is still a good indicator of the population's spatial distribution. During the last pentad there was only one unverified case of lynx mortality on the Ljubljana-Zagreb highway in 2008 (Poličnik et al. 2010). It was registered in reports of the Slovenian motorway company DARS, but this data is not reliable since the carcass was not preserved, checked or photographed, and it was determined to be a lynx only by an unidentified DARS employee (B. Pokorny, personal communication). During the last pentad the competent Ministry issued no hunting quota. As the lynx population size was estimated to be substantially declining, the decision of the Ministry was that hunting to regulate the population and to maintain higher tolerance for lynx is not eligible anymore (Marn 2008). In the period between 1978 and 1993 lynx were hunted, similarly to Norway for recreational hunting and for other reasons (Herfindal et al. 2005). Only C3 category data are available in the area of Trnovski gozd in the south-west and Kamnik-Savinj a Alps in the north. Although lynx presence in this region currently cannot be confirmed, C3 category data can be useful to indicate potential 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 YEAR -O-LPN JELEN -Щ-LPN MEDVED Figure 4: Dynamics of recorded lynx presence data within the monitoring programme in state hunting reserves LPN Jelen and LPN Medved. Slika 4: Dinamika zbranih podatkov znakov prisotnosti v okviru monitoringa v LPN Jelen in LPN Medved. xu np yo L P .. u >-0 = Л ■ ^ a E 3 E о LO H с 1—