Estonia – Eesti

Ecoregions
Baltic Sea, Sarmatic mixed forests

Biome
(Temperate broadleaf and mixed forests)

Predation on livestock is a cause of serious and long-lasting conflict between farmers and wildlife, promoting negative public attitudes and endangering conservation of large carnivores. However, while large carnivores, especially the grey wolf (Canis lupus), are often blamed for killing sheep and other farm animals, free-ranging dogs may also act as predators. To develop appropriate measures for livestock protection, reliable methods for identifying predator species are critical. Identification of predators from visual examination of livestock wounds can be ambiguous and genetic analysis is strongly preferable for accurate species determination. To estimate the proportion of wolves and dogs implicated in sheep predation, we developed a sensitive genetic assay to distinguish between wolves and domestic dogs. A total of 183 predator saliva samples collected from killed sheep in Estonia were analysed. The assay identified the predator species in 143 cases (78%). Sheep were most often killed by wolves (81%); however, predation by dogs was substantial (15%). We compared the molecular results with field observations conducted by local environmental officials and recorded some disagreement, with the latter underestimating the role of dogs. As predator saliva samples collected from prey are often of poor quality, we suggest using mitochondrial DNA as a primary tool to maximise the number of successfully analysed samples. We also suggest adopting forensic DNA analysis more widely in livestock predation assessments as a legislative measure since misidentification that is biased against wolves can be counterproductive for conservation by enhancing conflict with society and leading to increased culling and poaching.

After a long and deliberate persecution, the grey wolf (Canis lupus) is slowly recolonizing its former areas in Europe, and the genetic consequences of this process are of particular interest. Wolves, though present in mainland Estonia for a long time, have only recently started to recolonize the country’s two largest islands, Saaremaa and Hiiumaa. The main objective of this study was to analyse wolf population structure and processes in Estonia, with particular attention to the recolonization of islands. Fifteen microsatellite loci were genotyped for 185 individuals across Estonia. As a methodological novelty, all putative wolf-dog hybrids were identified and removed (n = 17) from the dataset beforehand to avoid interference of dog alleles in wolf population analysis. After the preliminary filtering, our final dataset comprised of 168 “pure” wolves. We recommend using hybrid-removal step as a standard precautionary procedure not only for wolf population studies, but also for other taxa prone to hybridization. STRUCTURE indicated four genetic groups in Estonia. Spatially explicit DResD analysis identified two areas, one of them on Saaremaa island and the other in southwestern Estonia, where neighbouring individuals were genetically more similar than expected from an isolation-by-distance null model. Three blending areas and two contrasting transition zones were identified in central Estonia, where the sampled individuals exhibited strong local differentiation over relatively short distance. Wolves on the largest Estonian islands are part of human-wildlife conflict due to livestock depredation. Negative public attitude, especially on Saaremaa where sheep herding is widespread, poses a significant threat for island wolves. To maintain the long-term viability of the wolf population on Estonian islands, not only wolf hunting quota should be targeted with extreme care, but effective measures should be applied to avoid inbreeding and minimize conflicts with local communities and stakeholders.

Ajal, mil mitmete hundipopulatsioonide levila on Euroopas suurenemas, on teadmised hundi populatsioonigeneetikast vajalikud liigi jaoks oluliste kaitse- ja majandamisotsuste tegemiseks ja seda nii kohalike populatsioonide kui ka üleeuroopalisel tasandil. Käesoleva töö peamisteks eesmärkideks oli uurida Eesti ja Läti hundipopulatsioonide struktuuri ja –protsesse, hübridiseerumist koertega ning laiemalt kogu Euroopa huntide ruumilis-geneetilise mitmekesisuse mustreid ja trende. Kasutades nii emaliini, isaliini kui ka biparentaalseid geneetilisi markereid kombineerivat analüüsi, tuvastasime Eestis (esmakordselt) ja Lätis hundi ja koera hübriidid, sealjuures kaks hübriidi Lätist esindasid väga haruldast, Euroopas esmakordselt tuvastatud hübridiseerimisjuhtumit – emase koera ja isase hundi vahel. Eestit ja Lätit hõlmav hundipopulatsiooni geneetilisel analüüsil leiti neli geneetiliselt eristuvat rühma ning uudne DResD analüüs tuvastas populatsioonis migratsioonikoridori ning liikumisbarjääre ja kontakttsoone eri geneetiliste rühmade vahel. Suuremat osa Euroopa hundipopulatsioonidest hõlmav meta-analüüs tuvastas olulise ruumilise mitmekesisuse trendi – huntide madalaim geneetiline mitmekesisus esines Euroopa edelaosas ja kõrgeim kirdeosas. Tulemustes selgunud ruumilise autokorrelatsiooni vahemik 650-850 km näitab, et konkreetse hundipopulatsiooni geneetilist mitmekesisust võivad mõjutada hundipopulatsioonid, mis asuvad kuni 850 km kaugusel. Enamik Euroopa hundipopulatsioonidest on silmitsi sarnaste, inimese poolt otseselt või kaudselt seotud ohtudega: küttimine (sealhulgas salaküttimine), inimeste madal sallivus hundi suhtes, konfliktid kariloomade murdmise tõttu, elupaikade hävimine ning võimalik hübridiseerumine koertega. Selleks, et hunt säiliks Euroopas pikka aega ja soodsas seisundis, on vaja suurendada Euroopa hundipopulatsioonide üldist arvukust ja soodustada loomade levikut ja populatsioonide-siseseid ja -vahelisi seoseid. Hundi teaduspõhiseks kaitsmiseks ja majandamiseks nii piirkondlikel kui ka üleeuroopalisel skaalal, on hundipopulatsioone vaja hallata kui bioloogilisi üksusi, mis nõuab kõiki Euroopa hundipopulatsioone hõlmavaid täiendavaid geneetilisi analüüse, et teha kindlaks populatsioonide täpne arv, ruumiline jaotus, geenisiirde ulatused ning hübridiseerumise sageduse koertega. As many wolf populations in Europe are expanding their range, knowledge of population genetics are of great importance for effective conservation and management of the species at both local and over-European scales. The main goal of this thesis was to provide information on wolf population structure and processes in Europe with a particular emphasis on Estonia and Latvia, including the wolf-dog hybridization. Using a combined analysis of maternal, paternal and biparental genetic markers, hybridization between grey wolf and domestic dog was ascertained in Estonia (for the first time) and in Latvia. The two hybrids from Latvia represented a very rare case of hybridization – the first record from Europe – between a female dog and a male wolf. Population structure analysis demonstrated that wolf popu¬lation shared between Estonia and Latvia is represented by four genetic groups. The spatially explicit DResD analysis provided clear evidence of spatial variation of genetic divergence, revealing a migration corridor, barriers, and several contact zones between different genetic groups. In a meta-analysis covering most of the European wolf populations, significant spatial trend in heterozygosity across Europe from south-west (lowest genetic diversity) to north-east (highest) was found. The range of spatial autocorrelation of 650−850 km suggests, that the genetic diversity of a given wolf population can be influenced by populations up to 850 km away. Various human-related factors are undoubtedly the main source of threats to wolf populations in Europe: the majority of populations face similar common threats such as overharvesting (including poaching), low public acceptance, conflicts due to livestock depredation, habitat destruction, barriers to gene flow and interactions with dogs leading to possible hybridization. For the long-term survival and favourable conservation status of European wolves there is a need to increase the overall population size and favour wolf dispersal and connectivity among and within populations. For science-based wolf conservation and manage¬ment at regional and Europe-wide scales it was suggested to manage wolf populations according to biological units, which requires additional genetic analysis covering all wolf populations in Europe to define the exact number and spatial distribution of populations.

The article attempts to bridge semiotics with species conservation and management. Biosemiotic and cultural semiotic methodology is applied in the analysis of a case study – the early occurrence of the golden jackal (Canis aureus) in Estonia. Nine semi-structured interviews were carried out with the local inhabitants of the Matsalu region, professional zoologists and environmental officials who were involved in the golden jackals’ discourse. The interviews were analyzed for interactions between golden jackals and humans, expected ecological effects of golden jackals, communication between different interest groups and central cultural motifs used to interpret the new species. It is argued that in the development of this discourse, the golden jackals’ own activity has played an essential role. At the same time, human cultural models also influence the interpretation of a new species to a considerable degree. Two of such models – the opposition of the own and the alien and the “settler’s” narrative – are brought out and analyzed. The effect of the fear of the unknown is also specified. To improve human communication about new or invasive species, it is suggested to raise awareness of the underlying cultural models and to use integrative communication as the developing discourse is dynamical and constantly changing for all interest groups. For a semiotic study of species management, it is suggested to combine methodology from biosemiotics, cultural semiotics and actor-network theory.

Studies on hybridization have proved critical for understanding key evolutionary processes such as speciation and adaptation. However, from the perspective of conservation, hybridization poses a concern, as it can threaten the integrity and fitness of many wild species, including canids. As a result of habitat fragmentation and extensive hunting pressure, gray wolf (Canis lupus) populations have declined dramatically in Europe and elsewhere during recent centuries. Small and fragmented populations have persisted, but often only in the presence of large numbers of dogs, which increase the potential for hybridization and introgression to deleteriously affect wolf populations. Here, we demonstrate hybridization between wolf and dog populations in Estonia and Latvia, and the role of both genders in the hybridization process, using combined analysis of maternal, paternal and biparental genetic markers. Eight animals exhibiting unusual external characteristics for wolves – six from Estonia and two from Latvia – proved to be wolf-dog hybrids. However, one of the hybridization events was extraordinary. Previous field observations and genetic studies have indicated that mating between wolves and dogs is sexually asymmetrical, occurring predominantly between female wolves and male dogs. While this was also the case among the Estonian hybrids, our data revealed the existence of dog mitochondrial genomes in the Latvian hybrids and, together with Y chromosome and autosomal microsatellite data, thus provided the first evidence from Europe of mating between male wolves and female dogs. We discuss patterns of sexual asymmetry in wolf-dog hybridization.

Carcasses of 26 wolves were collected during the 2000/2001 and 2003/2004 hunting seasons and examined for helminths. Thirteen helminth species were recorded: one trematode (Alaria alata), seven cestodes (Diphyllobothrium latum, Mesocestoides lineatus, Taenia hydatigena, Taenia multiceps, Taenia ovis, Taenia pisiformis, and Echinococcus granulosus), and five nematode species (Uncinaria stenocephala, Toxascaris leonina, Toxocara canis, Trichinella nativa, and Trichinella britovi). The most common species were A. alata and U. stenocephala. Mature Echinococcus granulosus was found and described for the first time in Estonia, and its identity verified using PCR-RFLP analysis. Sequencing a fragment of the mitochondrial DNA NADH dehydrogenase 1 (mtND1) gene showed that the E. granulosus strain from Estonia was identical to strain G10, recently characterized in reindeer and moose in Finland.

When planning the management of large predators, wildlife managers have to take into account the attitude of the population. A relevant poll using a unified methodology was arranged in three Baltic countries, Poland and Norway. In Estonia, completed questionnaires were received from 1,700 people. Along with personal data (incl. demographic characteristics: sex, age, level of education, etc.), a questionnaire posed 22 different questions designed to reveal the respondents’: attitude towards population size and dispersal patterns of large predators; acceptable distance to large carnivores; personal experience with large carnivores; confidence in various institutions in matters concerning large predators; general (and environmental) values and attitudes in life as a background. Survey results confirm that hatred for and fear of large predators are generally not characteristic of Estonians. Extreme views are almost completely lacking and a rational attitude seems to prevail. To the majority of the respondents the present number of large predators appears to be ideal.

Winter diets of wolfCanis lupus Linnaeus, 1758 and lynxLynx lynx Linnaeus, 1758 in Latvia and Estonia were investigated in 1997–2000 based on stomach contents of hunted animals and scats. Ungulates appeared to be the staple food for both predators. Lynx diet to a high extent consisted of cervids (Estonia 52% frequency of prey, Latvia 88%), roe deer dominating. Mountain hareLepus timidus made up from 9% (Latvia) to 31% (Estonia) of the lynx diet, and red foxVulpes vulpes 7% in Estonian sample. Wolf diet was more diverse; besides cervids (44% in Latvia, 63% in Estonia) it included wild boar Sus scrofa (32% in Latvia, 17% in Estonia), carrion, small rodents, and other food items. Proportion of empty stomachs was high both in wolves (37%) and lynxes (35%) in Latvia. Range of stomach content weights varied from zero to more than 4 kg in wolves and almost 1.5 kg in lynx. Pianka’s indices of food niche overlapped significantly between species and countries (0.85–0.99).

This paper reviews several big fluctuations in moose (Alces alces) numbers and related problems in Estonia during the last century. The biggest conflict appeared during the period 1960 – 1980, when the moose population achieved its highest density. The result of the overpopu-lation of moose was extensive forest damage. The establishment of a monitoring system and its acceptance by game management authorities at the beginning of the 1990s contributed to the improvement of the situation. The monitoring includes both the estimation of moose population parameters and estimation of moose influence on forest regeneration. Current moose numbers match the optimal population level outlined in the Estonian Environmental Strategy, approximately 10,000 animals, and forest damage has decreased. Estonia is a small country, rich in forests and bogs, situated on the shores of the Baltic Sea. Almost 50% of its surface is covered with forest, providing moose (Alces alces) with excellent natural habitat. At the same time, forestry is of great importance to the national economy. The forest is a resource shared by both man and moose, and sometimes conflicts arise. Through the ages Estonia has experienced several unde-sirable fluctuations of its moose population, a phenomenon shared throughout the Baltic region (Baleishis et al. 1998). Maximum populations have been pleasing to hunters but disturbing to foresters and vice versa. It is now commonly understood that the most important means for avoiding such conflict is adequate information concerning both the moose population and the condition of the young forest. Until recently, moose popula-tion data (official survey data) were based only on the reports of hunters and were very subjective. Since 1994, the monitoring of the moose population has been financed both by the state budget and by the state Center for Environmental Investments.

Wolf (Canis lupus) diet was studied in Alam-Pedja Nature Reserve from October to April 1999–2001. 119 wolf scats were collected and analysed. Remains of eight mammal species were found in wolf scats of which ungulates formed nearly 80%. Wolf diet in the nature reserve consisted mainly of wild boar (Sus scrofa; 37%), moose (Alces alces; 30.5%) and roe deer (Capreolus capreolus; 12.1%). A proportion of moose in ungulate biomass was calculated to be 77.5%; wild boar 20.4% and roe deer only 2%. It was found that wolf diet in the nature reserve differed from that of Estonia in general. We have concluded, that in areas with insufficient roe deer availability, wild boar and moose form the main prey items for wolf. It was suggested, that pack movements in area are mostly influenced by the localisation of prey animals and controlling of pack territory.