Reproduction and Mortality of Finnish Semi-Domesticated Reindeer in Relation to Density and Management Strategies

We assessed the effects of management strategies during 1960-73 relative to strategies used during 1974-87 on the reproduction and mortality of 56 semi-domesticated herds of Finnish reindeer (Rangifer tarandus tarandus). During 1960-73, reindeer fed exclusively on natural forage growing on their range, and reindeer were harvested mostly as adults. These strategies were modified starting in 1974 to include supplemental feeding in the southern part of the Finnish reindeer range and calf harvesting throughout the range. We found significantly higher calf/female ratios, lower mortality, and less variation in both calf/female ratios and mortality during 1974-87 than during 1960-73. These changes occurred in spite of increased animal density. Coefficients of variation in calf/female ratio and mortality were negatively correlated with the prevalence of mature spruce forests, which are rich in arboreal lichens. Mean calf/female ratio and mortality rate depended on reindeer density only in the southern region during 1960-73. During 1974-87 these did not depend on density in any region. Within herds, calf/female ratio did not depend on density in most cases (98%), while in the later period the relationship between calf production and density was positive in some cases (25%). Mortality depended more often on density during the earlier (46% of herds) than the later (23% of herds) period. Calf harvesting influenced mortality more than supplemental feeding and virtually freed reindeer from density-dependent limitations. Supplemental feeding was used to compensate for deterioration of range resulting from overgrazing and logging of mature forests rich in arboreal lichens.Key words: reproduction, mortality, density dependence, reindeer, Rangifer tarandus, management, FinlandOn a évalué les retombées des stratégies d'aménagement utilisées entre 1960 et 1973 par rapport à celles utilisées de 1974 à 1987 sur la reproduction et la mortalité de 56 troupeaux semi-domestiques de caribous finlandais (Rangifer tarandus tarandus). Au cours de la période allant de 1960 à 1973, les caribous se nourrissaient uniquement de fourrage naturel provenant de leur territoire, et le prélèvement des caribous s'effectuait en majorité sur des animaux adultes. À partir de 1974, ces stratégies ont été modifiées pour inclure un supplément à l'alimentation du caribou finlandais dans la partie sud de son territoire ainsi que le prélèvement de jeunes animaux sur la totalité du territoire. On a trouvé qu'au cours de la période allant de 1974 à 1987, le taux veaux/femelles était considérablement plus élevé, la mortalité était bien moindre et les fluctuations dans le taux veaux/femelles comme dans la mortalité était moindres qu'au cours de la période allant de 1960 à 1973. Ces changements se sont produits en dépit d'une augmentation de la densité des animaux. Les coefficients de variation dans le taux veaux/femelles et la mortalité avaient une corrélation négative avec la prédominance de forêts d'épinettes matures, où abondent les lichens corticicoles. La moyenne du taux veaux/femelles et du taux de mortalité ne dépendait de la densité du caribou que dans la partie méridionale entre 1960 et 1973. Entre 1974 et 1987, ces paramètres n'étaient fonction de la densité dans aucune région. Au sein des troupeaux, le taux veaux/femelles n'était pas fonction de la densité dans la plupart des cas (98 p. cent), alors que dans la deuxième période de l'étude, le rapport entre la production de veaux et la densité était positif dans quelques cas (25 p. cent). La mortalité dépendait plus souvent de la densité au cours de la première période de l'étude (45 p. cent) qu'au cours de la seconde (23 p. cent). Le prélèvement des veaux avait une influence sur la mortalité plus que ne l'avait le supplément à l'alimentation et libérait pratiquement le caribou des restrictions dues à la dépendance de la densité. Le supplément à l'alimentation était utilisé comme compensation à la détérioration du territoire due au surpâturage et à l'exploitation forestière de forêts matures riches en lichens corticicoles.Mots clés: reproduction, mortalité, fonction de la densité, renne, Rangifer tarandus, aménagement, Finland

Impact of reindeer grazing on ground-dwelling Carabidae and Curculionidae assemblages in Lapland

Reindeer Rangifer tarandus L. grazing shapes forest vegetation, microclimate, and soil respiration in Lapland, especially due to grazing on lichens (Cladina). We studied how these changes and their magnitude affect ground-dwelling species of beetle families Carabidae (predators) and Curculionidae (herbivores), by using pitfall traps to collect invertebrates from pairs of grazed and ungrazed study plots over a wide range of site types. Changes in abundance, composition, richness and diversity of beetle assemblage were tested in relation to magnitude of the impacts on vegetation. The species compositions of Carabidae and Curculionidae differed between grazed and ungrazed plots in all sites. The relative difference between grazed and ungrazed plots in the number of individuals increased linearly with the impact of reindeer on vegetation cover. Carabid beetles, as a family, were more common in grazed plots in all sites. Curculionid beetles were more common in ungrazed plots in the birch dominated sites. This difference was mainly due to the species that feeds on deciduous leaves. In the pine dominated sites with high Cladina cover and more changes in ground vegetation, the number of curculionids feeding on conifers was higher in grazed plots. Species richness and diversity (H') of both families were higher in grazed plots. Of the total 27 species, 11 were found only in grazed plots, while not a single species was found only in ungrazed plots. The relative difference between plots in diversity and evennes (H'/H' max) had humped response to the difference in Cladina cover. The diversity values were greater in grazed plots at the intermediate levels of grazing impact, and only in sites with very low or extremely high Cladina cover difference was the diversity higher in ungrazed plots. The response of beetle diversity resembled the hypotheses suggested for the relationship between grazing and vegetation diversity: greatest positive effect at intermediate grazing intensity and negative effects at unproductive sites

Admixture and gene flow from Russia in the recovering Northern European brown bear (Ursus arctos)

Large carnivores were persecuted to near extinction during the last centuries, but have now recovered in some countries. It has been proposed earlier that the recovery of the Northern European brown bear is supported by migration from Russia. We tested this hypothesis by obtaining for the first time continuous sampling of the whole Finnish bear population, which is located centrally between the Russian and Scandinavian bear populations. The Finnish population is assumed to experience high gene flow from Russian Karelia. If so, no or a low degree of genetic differentiation between Finnish and Russian bears could be expected. We have genotyped bears extensively from all over Finland using 12 validated microsatellite markers and compared their genetic composition to bears from Russian Karelia, Sweden, and Norway. Our fine masked investigation identified two overlapping genetic clusters structured by isolation-by-distance in Finland (pairwise FST = 0.025). One cluster included Russian bears, and migration analyses showed a high number of migrants from Russia into Finland, providing evidence of eastern gene flow as an important driver during recovery. In comparison, both clusters excluded bears from Sweden and Norway, and we found no migrants from Finland in either country, indicating that eastern gene flow was probably not important for the population recovery in Scandinavia. Our analyses on different spatial scales suggest

Impact of reindeer grazing on ground-dwelling Carabidae and Curculionidae assemblages in Lapland

Reindeer Rangifer tarandus L. grazing shapes forest vegetation, microclimate, and soil respiration in Lapland, especially due to grazing on lichens (Cladina). We studied how these changes and their magnitude affect ground-dwelling species of beetle families Carabidae (predators) and Curculionidae (herbivores), by using pitfall traps to collect invertebrates from pairs of grazed and ungrazed study plots over a wide range of site types. Changes in abundance, composition, richness and diversity of beetle assemblage were tested in relation to magnitude of the impacts on vegetation. The species compositions of Carabidae and Curculionidae differed between grazed and ungrazed plots in all sites. The relative difference between grazed and ungrazed plots in the number of individuals increased linearly with the impact of reindeer on vegetation cover. Carabid beetles, as a family, were more common in grazed plots in all sites. Curculionid beetles were more common in ungrazed plots in the birch dominated sites. This difference was mainly due to the species that feeds on deciduous leaves. In the pine dominated sites with high Cladina cover and more changes in ground vegetation, the number of curculionids feeding on conifers was higher in grazed plots. Species richness and diversity (H’) of both families were higher in grazed plots. Of the total 27 species, 11 were found only in grazed plots, while not a single species was found only in ungrazed plots. The relative difference between plots in diversity and evennes (H’/H’max) had humped response to the difference in Cladina cover. The diversity values were greater in grazed plots at the intermediate levels of grazing impact, and only in sites with very low or extremely high Cladina cover difference was the diversity higher in ungrazed plots. The response of beetle diversity resembled the hypotheses suggested for the relationship between grazing and vegetation diversity: greatest positive effect at intermediate grazing intensity and negative effects at unproductive sites

Potential for increased connectivity between differentiated wolverine populations

Information on genetic population structure provides important knowledge for species conservation. Yet, few studies combine extensive genetic data to evaluate the structure and population dynamics of transboundary populations. Here we used single nucleotide polymorphisms (SNPs), microsatellites and mitochondrial haplotypes to analyze the genetic population structure of wolverines (Gulo gulo) across Fennoscandia using a long-term monitoring dataset of 1708 individuals. Clear population subdivision was detected between the Scandinavian and the eastern Finnish population with a steep cline in the contact zone. While the Scandinavian population showed isolation by distance, large swaths of this population were characterized by high connectivity. Areas with high resistance to gene flow are likely explained by a combination of factors, such as historical isolation and founder effects. From a conservation perspective, promoting gene flow from the population in eastern Finland to the northwest of Scandinavia could augment the less variable Scandinavian population, and increase the demographic resilience of all subpopulations. Overall, the large areas of low resistance to gene flow suggest that transboundary cooperation with aligned actions of harvest and conflict mitigation could improve genetic connectivity across Finland, Sweden, and Norway

Non-invasive genetic monitoring involving citizen science enables reconstruction of current pack dynamics in a re-establishing wolf population

Background: Carnivores are re-establishing in many human-populated areas, where their presence is often contentious. Reaching consensus on management decisions is often hampered by a dispute over the size of the local carnivore population. Understanding the reproductive dynamics and individual movements of the carnivores can provide support for management decisions, but individual-level information can be difficult to obtain from elusive, wideranging species. Non-invasive genetic sampling can yield such information, but makes subsequent reconstruction of population history challenging due to incomplete population coverage and error-prone data. Here, we combine a collaborative, volunteer-based sampling scheme with Bayesian pedigree reconstruction to describe the pack dynamics of an establishing grey wolf (Canis lupus) population in south-west Finland, where wolf breeding was recorded in 2006 for the first time in over a century.Results: Using DNA extracted mainly from faeces collected since 2008, we identified 81 individual wolves and assigned credible full parentages to 70 of these and partial parentages to a further 9, revealing 7 breeding pairs. Individuals used a range of strategies to obtain breeding opportunities, including dispersal to established or new packs, long-distance migration and inheriting breeding roles. Gene flow occurred between all packs but inbreeding events were rare.Conclusions: These findings demonstrate that characterizing ongoing pack dynamics can provide detailed, locally-relevant insight into the ecology of contentious species such as the wolf. Involving various stakeholders in data collection makes these results more likely to be accepted as unbiased and hence reliable grounds for management decisions

Brown bear attacks on humans : a worldwide perspective

The increasing trend of large carnivore attacks on humans not only raises human safety concerns but may also undermine large carnivore conservation efforts. Although rare, attacks by brown bears Ursus arctos are also on the rise and, although several studies have addressed this issue at local scales, information is lacking on a worldwide scale. Here, we investigated brown bear attacks (n = 664) on humans between 2000 and 2015 across most of the range inhabited by the species: North America (n = 183), Europe (n = 291), and East (n = 190). When the attacks occurred, half of the people were engaged in leisure activities and the main scenario was an encounter with a female with cubs. Attacks have increased significantly over time and were more frequent at high bear and low human population densities. There was no significant difference in the number of attacks between continents or between countries with different hunting practices. Understanding global patterns of bear attacks can help reduce dangerous encounters and, consequently, is crucial for informing wildlife managers and the public about appropriate measures to reduce this kind of conflicts in bear country.Peer reviewe