Scat analysis of gray wolves (Canis lupus) in Slovenia

Volk (Canis lupus) je oportunistični plenilec, ki pleni predvsem velike sesalce. Njegova prehrana se zelo razlikuje med posameznimi območji, zato je pomembno pridobiti lokalne podatke iz različnih delov njegovega areala. V Sloveniji je prehrana volka slabo raziskana. V članku predstavljamo rezultate preliminarne raziskave, v kateri smo analizirali 30 iztrebkov volkov, nabranih po večjem delu razširjenosti volka v Sloveniji. S pomočjo mikroskopskeanalize dlak in preiskave zob ter postkranialnih delov skeleta iz iztrebkov smo določili plenske vrste ter izračunali njihovo frekvenco pojavljanja in delež zaužite biomase. Kot glavni plen volka v Sloveniji so se izkazali cervidi (Cervidae), ki smo jih našli v 87 % iztrebkov in so sestavljali 85 % zaužite biomase. V manjši meri so se volkovi hranili še z mladiči divjega prašiča (Sus scrofa7 % iztrebkov, 5 % zaužite biomase) in ostanki domačih živali (7 % iztrebkov, 10 % zaužite biomase).Gray wolf (Canis lupus) is an opportunistic predator, hunting mainly large mammals. Its diet varies substantially between different regionsit is necessary, therefore, to obtain reliable data from different parts of the wolf\u27s range. In Slovenia, the wolf\u27s diet has been poorly studied. In the present preliminary analysis, we analyzed 30 wolf scats collected throughout the wolf range in the country. We determined prey species using microscopic analysis of ground hairs and inspection of teeth and postcranial skeletal remains. For each prey group we calculated the frequency of occurrence and estimated the consumed biomass. In Slovenia, the wolf\u27s main prey are cervids (Cervidae), which were found in 87% of samples and represented 85% of consumed biomass. To a lesser extent, wolves were feeding on young wild boar (Sus scrofa7% of scats, 5% of consumed biomass) and on remains of domestic animals (7% of scats, 10% of consumed biomass)

Istraživanje čaglja (Canis aureus L.) na području sjeverne Dalmacije, Hrvatska: preliminarni rezultati

Preliminary results from the survey of golden jackals (Canis aureus) in Northern Dalmatia are presented. We used broadcasted jackal howls and monitored the response to determine the presence of jackal territorial groups. 19 jackal territorial groups were recorded in the NW part of Ravni kotari and 2 on Vir Island. The presence of territorial jackals on Pag Island could not be confirmed. For Ravni kotari the minimum estimated average territory density was 0.61–0.75 groups / 10 km2. However, there was relatively high variation of local densities in different parts of the study area, with the highest numbers in the vicinity of Zadar. For Vir Island the minimum estimated territory density was 1.15 groups / 10 km2. These values are relatively low compared to the results from a similar survey made in Greece.U radu se prezentiraju preliminarni rezultati istraživanja čaglja (Canis aureus) u sjevernoj Dalmaciji. Da bismo utvrdili prisutnost teritorijanih skupina čagljeva, odašiljali smo snimljeno glasanje čagljeva i pratili njihov odgovor. U sjeverozapadnom dijelu Ravnih kotara zabilježeno je 19 teritorijalnih grupa čagljeva, a na otoku Viru dvije. Teritorijalni čagljevi na otoku Pagu nisu potvrđeni. Procjena minimalne prosječne teritorijalne gustoće za Ravne kotare iznosi 0.61 – 0.75 skupina / 10 km2. U različitim dijelovima istraživanog područja postojala je visoka varijabilnost u gustoćama, najveća je zabilježena u blizini Zadra. Za otok Vir minimalna prosječna teritorijalna gustoća je 1.15 skupina / 10 km2. Te vrijednosti su relativno niže u usporedbi s onima iz sličnog istraživanja provedenog u Grčkoj

Effectiveness of wolf (Canis lupus) culling as a measure to reduce livestock depredations

Škoda, povzročena na domačih živalih, je ena glavnih težav pri ohranitvenem upravljanju z volkom (Canis lupus). Škodo se pogosto poskuša zmanjšati z odstrelom volkov. V pričujoči raziskavi smo analizirali učinke legalnega odstrela volkov na obseg škode v Sloveniji ter pripravili pregled podobnih raziskav iz tujine. V letih 1995-2009 je bilo legalno odstreljenih 51 volkov in zabeleženih 2221 primerov napadov volkov na domače živali. S statističnimi analizami nismo ugotovili nobenih vplivov odstrela volkov na višino škode. Učinkov odstrela ni bilo zaslediti niti tedaj, ko smo med seboj primerjali najbolj ekstremna leta. Naši rezultati se ujemajo z izsledki tujih raziskav, ki prav tako opozarjajo, da (v nasprotju s splošnim prepričanjem!) trajnostni lov volkov ni učinkovit ukrep za zmanjšanje škode. Odstrel postane učinkovit šele, če z njim iztrebimo celo populacijo ali odstranimo večino volkov iz večjega območja. Ker je škoda na drobnici v Sloveniji resen problem in ker odstrel volkov očitno nima želenega učinka, priporočamo, da se v prihodnje napori in sredstva osredotočijo v bolj učinkovite ukrepe.Livestock depredations are one of the main challenges in the management of thegrey wolf (Canis lupus) and culling of the wolves is a measure often used in an attempt to reduce damages. In the present study we analyzed effects of the legal wolf culling on livestock depredations in Slovenia and made a reviewof similar studies from other regions. 51 wolves were legally culled and2,221 attacks on livestock were recorded in Slovenia in 1995-2009. Our analysis did not show any effects of the culling on the number of depredationsduring the study period. No effects were detected even when the most extreme years were compared. Our results are in agreement with those fromother studies that showed that sustainable hunting of wolves is not an effective measure to reduce live-stock depredations. Wolf removal becomes efficient only when wolves are completely exterminated or when the majority ofwolves are removed from a large area. Because depredation of small live-stock in Slovenia presents a serious problem and since wolf culling does not seem to be efficient, we recommend that more attention and resources should be focused on more effective measures

Legal implications of range expansions in a terrestrial carnivore:The case of the golden jackal (Canis aureus) in Europe

Due to global environmental changes, species are appearing more frequently in places where they have not previously occurred, and this trend is expected to continue. Such range expansions can create considerable challenges and confusion for management and policy, especially for species associated with conflicts and whose management is influenced by international legal frameworks. The golden jackal (Canis aureus) in Europe represents a good case study to address the questions related to management of naturally expanding species. We review the recent expansion of the golden jackal across the continent, and address several ensuing policy and legal questions that also have clear implications for other expanding species. To that end, we analyze the EU Habitats Directive and several other international legal instruments including the Convention on Biological Diversity and the Bern Convention on European Wildlife. We also review the status of the golden jackal under national legislation and highlight some of the management confusion due to recent range expansion and inadequate legal interpretation. Specific questions we address include in which cases an expanding species is to be considered an (invasive) alien species in countries where it did not formerly occur; what countries’ conservation obligations are with respect to expanding species; what difference it makes for those obligations whether or not a species historically occurred in a country; what scope exists for lethal control of its populations; what the prospects are for transboundary cooperation at the population level; and what responses are required when colonizing species hybridise with other wildlife or domestic animals

Golden jackal expansion in Europe: a case of mesopredator release triggered by continent-wide wolf persecution?

Top-down suppression by apex predators can limit the abundance and spatial distribution of mesopredators. However, this phenomenon has not been studied over long time periods in human-dominated landscapes, where the strength of this process might be limited. Here, we used a multi-scale approach to analyse interactions between two canids in the human-dominated landscapes of Europe. We tested the hypothesis that the range expansion of golden jackals (Canis aureus) was triggered by intensive persecution and resulting decline of the apex predator, the grey wolf (Canis lupus). To do so, we (1) reviewed literature to reconstruct the historic changes in the distribution and abundance of the two canid species on the continental scale, (2) analysed hunting data patterns for both species in Bulgaria and Serbia, and (3) surveyed jackal persistence in eight study areas that became re-colonized by territorial wolves. The observed trends were generally consistent with the predictions of the mesopredator release hypothesis and supported the existence of top-down suppression by wolves on jackals. We observed inverse patterns of relative abundance and distribution for both canid species at various spatial scales. In most (seven out of eight) cases of wolf re-colonization of jackal territories, jackals disappeared or were displaced out or to the periphery of the newly established wolf home-ranges. We suggest that wolf extermination could be the key driver that enabled the expansion of jackals throughout Europe. Our results also indicate that top-down suppression may be weakened where wolves are intensively persecuted by humans or occur at reduced densities in human-dominated landscapes, which has important management implications and warrants further research

Otkriće najjužnije populacije velebitske gušterice (Iberolacerta horvathi) tijekom istraživanja gmazova planine Dinare (Hrvatska)

The article presents results from a reptile survey conducted between 14 and 16 June 2013 in a montane and subalpine belt of the western part of Dinara Mountain in Croatia. The most interesting result is the southernmost finding of Horvath’s Rock lizard (Iberolacerta horvathi). In the survey area we also recorded eight other reptile species: Anguis fragilis, Lacerta agilis, L. viridis sensu lato, Podarcis muralis, P. melissellensis, Coronella austriaca, Zamenis longissimus, and Vipera ammodytes.U radu su iznijeti rezultati istraživanja gmazova između 14. i 16. lipnja 2013. godine u gorskom i pretplaninskom pojasu zapadnog dijela planine Dinare u Hrvatskoj. Najznačajniji je dosad najjužniji nalaz velebitske gušterice (Iberolacerta horvathi). U istraženom području zabilježeno je i osam drugih vrsta gmazova: Anguis fragilis, Lacerta agilis, L. viridis sensu lato, Podarcis muralis, P. melissellensis, Coronella austriaca, Zamenis longissimus i Vipera ammodytes

Using heterogeneous camera-trapping sites to obtain the first density estimates for the transboundary Eurasian lynx (Lynx lynx) population in the Dinaric Mountains

Estimating abundance of wild animal populations is crucial for their management and conservation. While spatial capture-recapture models are becoming increasingly common to assess the densities of elusive species, recent studies have indicated potential bias that can be introduced by unaccounted spatial variation of detectability. We used camera-trapping data collected in collaboration with local hunters from a transnational population survey of the Eurasian lynx (Lynx lynx) in Slovenia and Croatia, to provide the first density estimate for the threatened Eurasian lynx population in the Northern Dinaric Mountains. Population density was 0.83 (95% CI: 0.60-1.16) lynx/100 km(2), which is comparable to other reintroduced Eurasian lynx populations in Europe. Furthermore, we showed that baseline detection rate was influenced by the type of site used, as well as by sex of the individual and local behavioural response. Scent-marking sites had on average a 1.6- and 2.5-times higher baseline detection rate compared to roads and other locations, respectively. Scent-marking behaviour is common for several mammals, and selecting sites that attracts the targeted species is used to increase detection rates, especially for rare and cryptic species. But we show that the use of different location types for camera trapping can bias density estimates if not homogenously distributed across the surveyed area. This highlights the importance of incorporating not only individual characteristics (e.g., sex), but also information on the type of site used in camera trapping surveys into estimates of population densities

Predicting kill sites of an apex predator from GPS data in different multi-prey systems

© 2022 The Authors. Ecological Applications published by Wiley Periodicals LLC on behalf of The Ecological Society of America. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.Kill rates are a central parameter to assess the impact of predation on prey species. An accurate estimation of kill rates requires a correct identification of kill sites, often achieved by field-checking GPS location clusters (GLCs). However, there are potential sources of error included in kill-site identification, such as failing to detect GLCs that are kill sites, and misclassifying the generated GLCs (e.g., kill for nonkill) that were not field checked. Here, we address these two sources of error using a large GPS dataset of collared Eurasian lynx (Lynx lynx), an apex predator of conservation concern in Europe, in three multiprey systems, with different combinations of wild, semidomestic, and domestic prey. We first used a subsampling approach to investigate how different GPS-fix schedules affected the detection of GLC-indicated kill sites. Then, we evaluated the potential of the random forest algorithm to classify GLCs as nonkills, small prey kills, and ungulate kills. We show that the number of fixes can be reduced from seven to three fixes per night without missing more than 5% of the ungulate kills, in a system composed of wild prey. Reducing the number of fixes per 24 h decreased the probability of detecting GLCs connected with kill sites, particularly those of semidomestic or domestic prey, and small prey. Random forest successfully predicted between 73%–90% of ungulate kills, but failed to classify most small prey in all systems, with sensitivity (true positive rate) lower than 65%. Additionally, removing domestic prey improved the algorithm's overall accuracy. We provide a set of recommendations for studies focusing on kill-site detection that can be considered for other large carnivore species in addition to the Eurasian lynx. We recommend caution when working in systems including domestic prey, as the odds of underestimating kill rates are higher.publishedVersio