Snowmobile accidents and moose-car crashes are typical accidents in Northern Sweden. In this region there is about 1 snowmobile/10 inhabitants. The present paper combines previously published studies. The studies on snowmobile accidents are based on a material comprising all 61 fatally injured snowmobile drivers from the four northern counties of Sweden during the period 1973-1987. The helmet usage was analyzed in two clinical study populations including 200 injured from the county of Västerbotten from two periods 1979-1980 and 1985-86. Of the fatally injured (median age 32 years) 86% were driving under the influence of alcohol with a mean blood alcohol concentration of 0.17 g/ml. Serious head injuries were uncommon among persons driving without a helmet in the clinical material. Only in about 6% of the cases an open face helmet would probably have had an injury reducing effect. Drunken driving is an important etiological factor for fatal snowmobile accidents. Preventive measures must include information that the Traffic Temperance Law also applies to snowmobile riding. A helmet law for snowmobile riders does not seem to be motivated from the injury reduction point of view. According to official Swedish police statistics more than 400 car occupants are injured annually in crashes with a moose. The crash mechanism is special. Because of its long legs the body of the moose hits directly against the windshield, windshield pillars and front roof. During a period of three years 154 injured passenger car occupants were treated in the hospitals in Umeå and Skellefteå. Of both the front and rear seat occupants 80% suffered laceration injuries from glass or glass splinters.(ABSTRACT TRUNCATED AT 250 WORDS)
The paper describes the introduction of Mycobacterium bovis into Swedish deer herds and its possible consequences. The different control strategies applied are summarized as well as their shortcomings under the conditions of the Swedish outbreak. An alternative control, to be used in extensive deer herds, based only on slaughter and meat inspection is described. Finally, the efficiency of the implemented control and surveillance systems are discussed and possible improvements suggested.
Université de Lyon, Centre National de Recherche Scientifique, Unité Mixte de Recherche 5558, Laboratoire de Biométrie et Biologie Evolutive, 43 Boulevard du 11 Novembre 1918, Villeurbanne F-69622, France. email@example.com.
In seasonal environments, timing of reproduction is an important fitness component. However, in ungulates, our understanding of this biological process is limited. Here we analyze how age and body mass affect spatiotemporal variation in timing of ovulation of 6,178 Norwegian moose. We introduced a parametric statistical model to obtain inferences about the seasonal timing of ovulation peak, the degree of synchrony among individuals, and the proportion of individuals that ovulate. These components showed much more spatiotemporal variation than previously reported. Young (primiparous) and old (> or =11.5 years of age) females ovulated later than prime-aged (2.5-10.5 years of age) females. In all age classes, ovulation was delayed with decreasing body mass. Ovulation rates were lower and more variable among primiparous females than among older females. Young females required higher body mass than older females did to ovulate. The body-mass-to-ovulation relationship varied with age, showed large regional variation, and differed among years within region. These results suggest that (1) environmental and population characteristics contribute to shape seasonal variation in the breeding pattern and (2) large regional variation exists in the size-dependent age at maturity in moose. Hence, the life-history trade-off between reproduction and body growth should differ regionally in moose.
Over the past ten years, total mercury (THg) levels have been surveyed in Alaskan wildlife and fish as part of the Arctic Monitoring and Assessment (AMAP). Beyond these studies there is little historical data on THg levels in important subsistence species for people in Alaska. A survey of THg in caribou hair from archaeological deposits would provide data to develop temporal trends for this region of the Arctic. Caribou hair from a Western Thule settlement beneath the Alaska native village of Deering (ca. AD 1150) show variability in hair THg values, with a mean level (86 ng/g) which is in the range that is observed in modern Rangifer sp. (caribou and reindeer). Hair from House 1 had a THg mean level of 99.6 ng/g and hair from House 2 had a THg mean of 64.2 ng/g. This is the earliest reported record of mercury in caribou associated with human subsistence activities in the western North American Arctic, and is a first step toward compilation of a needed database through which to measure and evaluate exposure to mercury by people who rely heavily on caribou as a food source. We hypothesize that similarity in mercury values in archaeological samples of caribou and in contemporary samples would give an additional perspective on human exposure to mercury through caribou harvest and consumption today. Since this hypothesis will be more useful if evaluated at a regional rather than global scale, further studies will be needed at different archaeological sites across Alaska to determine the generality of this observation in relation to geographic scale.
We used an indirect enzyme-linked immunosorbent assay (iELISA) and the rose bengal test (RBT) to test for anti-Brucella antibodies in moose (Alces alces gigas), muskoxen (Ovibos moschatus), and plains bison (Bison bison bison) from various game management units (GMUs) in Alaska, US, sampled from 1982 to 2010. A portion of the sera had previously been tested with the standard plate test (SPT), the buffered Brucella antigen (BBA) card test, and the card test (CARD). No antibody-positive plains bison were identified. Anti-Brucella antibodies were detected in moose (iELISA, n=4/87; RBT, n=4/87; SPT, n=4/5; BBA, n=4/4) from GMU 23 captured in 1992, 1993, and 1995 and in muskoxen (iELISA, n=4/52; RBT, n=4/52; CARD, n=4/35) from GMUs 26A and 26B captured in 2004, 2006, and 2007. A negative effect of infection on the health of individuals of these species is probable. The presence of antibody-positive animals from 1992 to 2007 suggests presence of brucellae over time. The antibody-positive animals were found in northern Alaska, an area with a historically higher prevalence of Brucella-positive caribou, and a spillover of Brucella suis biovar 4 from caribou may have occurred. Brucella suis biovar 4 causes human brucellosis, and transmission from consumption of moose and muskoxen is possible.
Identifying factors shaping secondary sexual traits is essential in understanding how their variation may influence male fitness. Little information is available on the allocation of resources to antler growth in territorial ungulates with low sexual size dimorphism. We investigated phenotypic and environmental factors affecting both absolute and relative antler size of male roe deer in three contrasting populations in France and Sweden. In the three populations, we found marked age-specific variation in antler size, with an increase in both absolute and relative antler size between yearling and prime-age stages, followed by a decrease (senescence) for males older than 7 years. Antler size increased allometrically with body mass. This increase was particularly strong for senescent males, suggesting the evolution of two reproductive tactics: heavy old males invested particularly heavily in antler growth (potentially remaining competitive for territories), whereas light old males grew small antlers (potentially abandoning territory defense). Finally, environmental conditions had little effect on antler size: only population density negatively affected absolute antler size in one of the three populations. Antler size may therefore provide an honest signal of male phenotypic quality in roe deer. We discuss the implications of these results in terms of territory tenure and mating competition.
Partially migratory populations, where one portion of a population conducts seasonal migrations (migrants) while the other remains on a single range (residents), are common in ungulates. Studies that assess trade-offs between migratory strategies typically compare the amount of predation risk and forage resources migrants and residents are exposed to only while on separate ranges and assume both groups intermix completely while on sympatric ranges. Here we provide one of the first tests of this assumption by comparing the amount of overlap between home ranges of GPS-collared migrant and resident elk and fine-scale exposure to wolf predation risk and forage biomass at telemetry locations on a sympatric winter range in west-central Alberta, Canada. Overlap between migrant and resident home ranges increased throughout the winter, and both groups were generally intermixed and exposed to equal forage biomass. During the day, both migrants and residents avoided predation risk by remaining in areas far from timber with high human activity, which wolves avoided. However, at night wolves moved onto the grasslands close to humans and away from timber. Resident elk were consistently closer to areas of human activity and further from timber than migrants, possibly because of a habituation to humans. As a result, resident elk were exposed to higher night-time predation risk than migrants. Our study does not support the assumption that migrant and resident elk are exposed to equal predation risk on their sympatric range when human presence alters predation risk dynamics and habituation to humans is unequal between migratory strategies.
The impact of anthropogenic disturbance on the fitness of prey should depend on the relative effect of human activities on different trophic levels. This verification remains rare, however, especially for large animals. We investigated the functional link between habitat selection of female caribou (Rangifer tarandus) and the survival of their calves, a fitness correlate. This top-down controlled population of the threatened forest-dwelling caribou inhabits a managed forest occupied by wolves (Canis lupus) and black bears (Ursus americanus). Sixty-one per cent of calves died from bear predation within two months following their birth. Variation in habitat selection tactics among mothers resulted in different mortality risks for their calves. When calves occupied areas with few deciduous trees, they were more likely to die from predation if the local road density was high. Although caribou are typically associated with pristine forests, females selected recent cutovers without negative impact on calf survival. This selection became detrimental, however, as regeneration took place in harvested stands owing to increased bear predation. We demonstrate that human disturbance has asymmetrical consequences on the trophic levels of a food web involving multiple large mammals, which resulted in habitat selection tactics with a greater short-term fitness payoff and, therefore, with higher evolutionary opportunity.
Cites: Oecologia. 2005 Jun;144(2):257-6715891849
Cites: Proc Biol Sci. 2006 Jun 22;273(1593):1449-5416777736