Cumulative Impacts of Tourist Resorts on Wild Reindeer (Rangifer tarandus tarandus) during Winter

Potential avoidance by wild reindeer (Rangifer tarandus tarandus) of high-altitude tourist resorts during winter was investigated in and near Rondane National Park in Norway. Distribution of reindeer was mapped using systematic snowmobile surveys during 1991-96 and compared with results from investigations of snow and vegetation characteristics. Maternal reindeer avoided a 10 km zone around the resort. Cows and calves increased in density from 0.6 ± 0.6 reindeer/km² at 5-10 km from the resort to 7.6 ± 2.2 reindeer/km² at 15-25 km from the resort. Bulls and yearlings were more tolerant, constituting nearly 92% of all observed animals 5-10 km from the resort. Nearly all animals avoided the zone within 5 km of the resort. There were no significant differences in distribution of lichen heath, hardness of snow, integrated ram hardness index (IRH) values, or snow depths on ridges with increasing distance from the resort. Available biomass of lichens was ca. 1200 g/m² 0-5 km from the resort and decreased to a low of ca. 250 g/m² at 15-25 km distance, a pattern that probably reflects overgrazing as a result of avoiding the tourist resort. Such avoidance implies reduced forage intake during winter, substantial reduction in available habitat, and lower productivity of the herd. The results suggest that avoidance by wild animals of sources of anthropogenic disturbance may involve long-term impacts, such as reductions in carrying capacity, that are more serious than those expected from direct physiological stress.On a étudié le comportement d'évitement des stations touristiques de haute altitude que semble manifester le renne sauvage (Rangifer tarandus tarandus) en hiver, dans le parc national Rondane même et dans ses environs, en Norvège. La distribution du renne a été cartographiée à l'aide de relevés systématiques effectués en motoneige entre 1991 et 1996, et comparée avec les résultats d'études des caractéristiques de la neige et de la végétation. Les mères rennes évitaient une zone de 10 km autour de la station. Les femelles et leurs petits augmentaient en densité de 0,6 ± 0,6 renne/km² entre 5 et 10 km de la station, à 7,6 ± 2,2 renne/km² entre 15 et 25 km de la station. Les mâles et les jeunes d'un an manifestaient une plus grande tolérance, représentant près de 92 p. cent de tous les animaux observés entre 5 et 10 km de la station. Pratiquement tous les animaux évitaient la zone située dans un rayon de 5 km. On n'a pas trouvé de différences significatives en fonction de l'éloignement de la station, dans la distribution de la bruyère à lichens, la dureté de la neige, les valeurs de l'indice intégré de dureté au bélier ou l'épaisseur nivale sur les crêtes. La biomasse de lichens disponible était d'environ 1200 g/m² entre 0 et 5 km de la station et diminuait à un minimum d'environ 250 g/m² à une distance de 15 à 25 km, répartition qui reflète probablement un surpâturage résultant de l'évitement de la station touristique. Ce comportement a pour conséquence une réduction de la consommation de végétation durant l'hiver, une réduction substantielle de l'habitat disponible et une diminution de la productivité du troupeau. Les résultats suggèrent que l'évitement de sources de perturbation anthropogénique par les animaux sauvages peut avoir des répercussions à long terme, comme des baisses de la capacité de charge biogénique, répercussions qui sont plus graves que celles auxquelles on s'attend d'un stress physiologique direct

Landsrepresentativ overvåking av skogens vitalitet i Norge - kontroll 1997

Til sammen 40 overvåkingsflater med over 370 gran- og furutrær fra 4 tilfeldig valgte observatører ble kontrollert i forbindelse med feltregistreringene i 1997. Avvikene mellom observatører og kontrollør var større for gran i 1997 enn tidligere år. Det ble påvist systematiske avvik. Det var et generelt godt samsvar mellom observatør og kontrollør, hvor over halvparten av trærne hadde mindre enn 5% avvik. Større avvik i 1997 sammenlignet med 1996 skyldes sannsynligvis en større andel trær med lave kronetettheter, noe som medfører større vanskeligheter ved bedømmelsen. Det var store avvik i bedømmelsen av kronefarge, noe som kan skyldes kontroll på høsten, hvor det forekommer mer misfarging. Usikkerheten er størst ved vurdering av enkelttrær og enkeltflater. Vurderinger av endringer i kronetetthet og farge bør fortrinnsvis baseres på trender i et større materiale.publishedVersio

Bears are simply voles writ large: social structure determines the mechanisms of intrinsic population regulation in mammals

The literature reveals opposing views regarding the importance of intrinsic population regulation in mammals. Different models have been proposed; adding importance to contrasting life histories, body sizes and social interactions. Here we evaluate current theory based on results from two Scandinavian projects studying two ecologically different mammal species with contrasting body sizes and life history traits: the root vole Microtus oeconomus and the brown bear Ursus arctos. We emphasize four inter-linked behavioral aspects—territoriality, dispersal, social inhibition of breeding, and infanticide—that together form a density-dependent syndrome with potentially regulatory effects on population growth. We show that the two species are similar in all four behaviors and thus the overall regulatory syndrome. Females form matrilineal assemblages, female natal dispersal is negatively density dependent and breeding is suppressed in philopatric young females. In both species, male turnover due to extrinsic mortality agents cause infanticide with negative effects on population growth. The sex-biased and density-dependent dispersal patterns promote the formation of matrilineal clusters which, in turn, leads to reproductive suppression with potentially regulatory effects. Hence, we show that intrinsic population regulation interacting with extrinsic mortality agents may occur irrespective of taxon, life history and body size. Our review stresses the significance of a mechanistic approach to understanding population ecology. We also show that experimental model populations are useful to elucidate natural populations of other species with similar social systems. In particular, such experiments should be combined with methodical innovations that may unravel the effects of cryptic intrinsic mechanisms such as infanticid

The eVects of primiparity on reproductive performance in the brown bear

Abstract We studied the eVects of primiparity on litter size, oVspring size, and cub loss in brown bears (Ursus arctos) in two study areas (north, south) in Sweden from 1987 to 2006. Sexually selected infanticide (SSI) has been suggested previously as a mortality factor in our study populations. Females in the south became primiparous earlier than females in the north. Primiparous females had signiWcantly smaller litters of cubs than multiparous females. We found no evidence that primiparity was costly in terms of the interlitter interval. Primiparous mothers had a higher probability of cub loss than multiparous mothers. The probability of cub loss was analyzed separately for the premating and the mating season. The probability of cub loss by primiparous females in the pre-mating season increased with both increasing population density and deteriorating food conditions, whereas the probability of cub loss during the mating season decreased with increasing age of primiparity and increased with male turnover (a variable predicting SSI). The temporal patterns of cub loss by primiparous females suggested that the critical times for reproductive success by primiparous females were the pre-mating season (from birth to shortly after leaving the den) and the mating season. Cub loss in these periods was independent and caused by diVerent factors. Cub loss before the mating season seemed to be most inXuenced by food conditions, whereas that during the mating season appeared to be caused by SSI

Behavioral and Physiological Responses of Scandinavian Brown Bears (Ursus arctos) to Dog Hunts and Human Encounters

Innovations in biologging have offered new possibilities to better understand animals in their natural environment. Biologgers can be used by researchers to measure the impact of human disturbances on wildlife and guide conservation decisions. In this study, the behavioral and physiological responses of brown bears (Ursus arctos) to hunts using dogs (Canis lupus familiaris) and human encounters were assessed to better understand the impact of human outdoor activities on brown bears. In Scandinavia, brown bear hunting and the use of dogs during hunts is increasing in popularity. Nonetheless, not every hunt leads to a killed bear. This means that for each bear that is shot, multiple bears may be chased but not killed. In addition, bears can also be disturbed when encountering non-hunting humans. Heart rates, body temperatures, GPS coordinates and dual-axis activity data were collected from 52 simulated hunts (a simulated hunt using dogs with the bear allowed to flee at the end) and 70 human encounters (humans intentionally approaching the bear) that were carried out on 28 free-ranging female brown bears in two study areas in Sweden. The results showed that: (1) simulated hunts had a greater impact and induced a greater energy cost than human encounters; (2) the amount of time bears rested the day after the simulated hunts increased linearly with the duration of the simulated hunts, implying a lasting behavioral impact relative to the intensity of the disturbance. Although not tested in this study, brown bears that are repeatedly disturbed by dog hunts and human encounters may be unable to compensate the disturbances' energy cost, and their fitness may, therefore, be altered. If it is the case, this effect should be accounted for by managers

Pronounced expression of the lipolytic inhibitor G0/G1 Switch Gene 2 (G0S2) in adipose tissue from brown bears (Ursus arctos) prior to hibernation

Prior to hibernation, the brown bear (Ursus arctos) exhibits unparalleled weight gain. Unlike humans, weight gain in bears is associated with lower levels of circulating free fatty acids (FFA) and increased insulin sensitivity. Understanding how free-ranging brown bears suppress lipolysis when gaining weight may therefore provide novel insight toward the development of human therapies. Blood and subcutaneous adipose tissue were collected from immobilized free-ranging brown bears (fitted with GPS-collars) during hibernation in winter and from the same bears during the active period in summer in Dalarna, Sweden. The expression of lipid droplet-associated proteins in adipose tissue was examined under the hypothesis that bears suppress lipolysis during summer while gaining weight by increased expression of negative regulators of lipolysis. Adipose triglyceride lipase (ATGL) expression did not differ between seasons, but in contrast, the expression of ATGL coactivator Comparative gene identification-58 (CGI-58) was lower in summer. In addition, the expression of the negative regulators of lipolysis, G0S2 and cell-death inducing DNA fragmentation factor-a-like effector (CIDE)C markedly increased during summer. Free-ranging brown bears display potent upregulation of inhibitors of lipolysis in adipose tissue during summer. This is a potential mechanism for increased insulin sensitivity during weight gain and G0S2 may serve as a target to modulate insulin sensitivity

Movement and heart rate in the Scandinavian brown bear (<i>Ursus arctos</i>)

Background: Understanding animal movement facilitates better management and conservation. The link between movement and physiology holds clues to the basic drivers of animal behaviours. In bears, heart rate increases with the metabolic rate during the active phase. Their movement and heart rate change at seasonal and daily scales, and can also depend on environmental factors. Their behaviour is, therefore, flexible in activity patterns with high individual variations. The aim of this study was to establish the relationship between heart rate and distance travelled, and test whether this relationship was influenced by environmental (e.g., time of year and time of day) and biological (e.g., reproductive status, sex, body mass and age of the bears) factors. We analysed data of distance travelled and heart rate of 15 GPS-collared brown bears, both males and females, equipped with cardiac loggers in the south of Sweden in 2014–2017. Results: Heart rate increased with distances travelled exceeding 50 m in an hour, but this correlation depended on the day-of-year with higher heart rate in August than in May. Bears accompanied by cubs had lower heart rate than solitary bears especially in May. When movement was minimum (< 50 m in an hour), heart rate was not related to distance travelled and was very variable, regardless of the months. Conclusions: Our findings suggest that heart rate increases with long distances travelled, but varies with day-of-year and reproductive status, depending on the metabolic rate. Studying the change in heart rate in bears can help to evaluate their seasonal rhythms and how different factors affect them. This study illustrates the usefulness of combined bio-logging proxies, i.e., movement and heart rates in our case, in animal ecology. Distance travelled, GPS positions, Cardiac bio-logger, Seasonal variation, Reproductive statuspublishedVersio

Extrinsic and intrinsic factors drive the timing of gestation and reproductive success of Scandinavian brown bears

© 2022 Lemière, Thiel, Fuchs, Gilot-Fromont, Hertel, Friebe, Kindberg, Støen, Arnemo and Evans. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.Climate change is altering the reproductive phenology of many organisms, but the factors that influence the timing of gestation in ursids are still poorly understood. Higher temperatures in spring are already causing an earlier den exit in some brown bear populations, and a temporal mismatch between hibernation and reproduction could have dramatic consequences for reproductive success. Therefore, understanding the factors that control the timing of these events is important to forecast the consequences of climate change on population growth rates. In this study, we used abdominal temperature loggers and GPS collars with acceleration sensors on 23 free-ranging pregnant female brown bears living in two areas in Sweden (61◦N and 67◦N latitude) to pinpoint hibernation and reproductive events. We investigated how intrinsic and extrinsic factors influence the termination of embryonic diapause and parturition, as well as their impact on reproductive success. The termination of embryonic diapause was later in the northern area compared to the southern area and occurred earlier when ambient temperature at den entry was higher in both areas. In the southern area, young adults (i.e., females = 7 years old) had a delayed parturition when bilberry abundance was low the year of mating. Additionally, young adults had a lower reproductive success than adults and their probability to reproduce successfully was dependent on bilberry abundance, whereas adult females were not affected by this parameter. As den exit occurs later in the northern study area, we suggest that a later parturition might ensure that females lactate their cubs in the den for a reasonable amount of time while fasting. Similarly, a later parturition combined with an earlier emergence could allow young adults to spend less time in the den lactating if they could not reach an optimal body condition prior to hibernation. But as a result, their cubs are younger and more vulnerable when they leave the den leading to lower survival rates. Our results suggest that a decreased berry abundance in the fall could impact the reproductive and hibernation phenology of Scandinavian brown bear females and lead to a lower cub survival with potential consequences on the population dynamics.publishedVersio