| 1. |
- Arzel, Céline, et al.
(författare)
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Average mass of seeds encountered by foraging dabbling ducks in western Europe
- 2007
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Ingår i: Wildlife Biology. - 0909-6396 .- 1903-220X. - 0909-6396 ; 13:3, s. 328-336
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Tidskriftsartikel (refereegranskat)abstract
- Many dabbling ducks Anas spp. are largely granivorous, consuming a variety of seeds chiefly from aquatic plants. To assess the relative value and carrying capacity of wetlands for dabbling ducks, species-specific information about seed mass is needed, but it is still largely missing or scattered in the literature. By combining weights of seeds collected in the field with a literature review, we provide a reference table for seed mass of 200 western European plant taxa frequently encountered by foraging dabbling ducks. Seeds collected in the field were sampled in microhabitats and at depths at which ducks were observed to forage, and study sites represent wintering, staging as well as breeding areas within a flyway in western Europe. When combined with calorimetric data, the present reference table will aid managers and scientists in assessing the importance of seed food resources at different sites and during different parts of the annual cycle.
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| 2. |
- Elmberg, Johan, 1960-, et al.
(författare)
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The scientific basis for a new and sustainable management of migratory European ducks
- 2006
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Ingår i: Wildlife Biology. - 0909-6396 .- 1903-220X. ; 12:2, s. 121-127
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Tidskriftsartikel (refereegranskat)abstract
- It is an axiom in ecology that knowing the sheer number of individuals in a population is of very little help if the objective is to understand future and past changes in population size. Yet, this is exactly how migratory European ducks are monitored, many of which are important quarry species in several countries. We argue that present monitoring is insufficient to address objectives of wise use and sustainability such as those emphasised in recent management directives and multilateral international agreements. The two main problems are the almost total lack of reliable data on recruitment and mortality. We advocate a pan-European monitoring system based on undisputed scientific principles; i.e. a long-term, coordinated and standardised scheme that produces data about vital rates of duck populations as well as about harvest size. Data from such a scheme can be used by game biologists to produce predictive tools, thus providing a functional basis for management decisions for adaptive harvesting and conservation alike.
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| 3. |
- Elfström, M, et al.
(författare)
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Selection of denning habitats by Scandinavian brown bears Ursus arctos
- 2008
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Ingår i: Wildlife Biology. - 0909-6396 .- 1903-220X. ; 14:2, s. 176-187
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Tidskriftsartikel (refereegranskat)abstract
- We analyse the selection of denning habitats by Scandinavian brown bears Ursus arctos and test if there are differences related to sex and age. At the landscape level, the vegetation types within a 500-m radius around 250 dens used during 1990–2000 in south-central Sweden were analysed using a Geographical Information System (GIS). Compositional analysis (CA) was used to test if bears selected or avoided certain habitat types for denning. There were relatively few differences in habitat selection among bears of differences age or sex. Overall, as a group the bears showed distinct preferences in selection of denning habitats; selecting for open canopy (Scots pine Pinus sylvestris) forests and habitats with moist soil with rich vegetation, before closed canopy (older Norway spruce Picea abies and Scots pine) forests, young forest and clear cuts, mountain coniferous forests and bogs. Denning bears avoided water, alpine mountain-birch forest, deciduous forest, peat, exposed bedrock and gravel pits. Bears denned more on lower altitudes, easterly aspects and steeper slopes than was available. Furthermore, bears avoided intermediate-size roads, perhaps because they are the source of human disturbance, providing a combination of easy winter access (because they are ploughed) and relatively high traffic intensity.
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| 4. |
- Hedmark, Eva, et al.
(författare)
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Paternity and mating system in wolverines Gulo gulo
- 2007
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Ingår i: Wildlife Biology. - 0909-6396 .- 1903-220X. ; 13:Suppl.2, s. 13-30
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Tidskriftsartikel (refereegranskat)abstract
- Knowledge of the wolverine Gulo gulo mating system is limited. In this study, we use 20 microsatellite loci for paternity testing in 145 wolverine offspring with known mothers. Samples were collected during > 10 years in two Scandinavian populations, mainly in connection with radio-telemetry studies and as part of long-term population monitoring. In total, 51% of the offspring were assigned a father. Our results demonstrate that the wolverine exhibits a polygamous mating system as some males were shown to produce offspring with more than one female in a single year. Females often reproduced with the same male in subsequent breeding years, but sometimes changed their partner, potentially as a consequence of a change in the territory-holding male in the area. In the majority of litters, siblings were unambiguously assigned the same father, indicating that multiple paternity is rare. Of 23 breeding pairs, for which telemetry data were available, 20 had overlapping home ranges, suggesting that pair formation generally is consistent with the territories held by wolverine males and females.
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| 5. |
- Rönnegård, Lars, et al.
(författare)
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Evaluation of four methods used to estimate population density of moose Alces alces
- 2008
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Ingår i: Wildlife Biology. - 0909-6396 .- 1903-220X. ; 14:3, s. 358-371
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Tidskriftsartikel (refereegranskat)abstract
- Various survey methods are used to monitor and manage ungulate popualations. The choice of optimal method depends on estimation accuracy, management objective and financial constraints. Here we compare estimates produced by four different methods for estimating population size, i.e. aerial counts, hunter observations, pellet group counts and cohort analysis. A Swedish moose Alces alces population was studied during 1973-2005 in the Grimso Wildlife Research Area (135 km(2)). The highest correlation was found between cohort analysis and aerial counts (r = 0.69. P < 0.05). and the hunter observations and the aerial counts (r = 0.76. P < 0.10). The different methods produced relatively consistent trends in population estimates over years. Pellet group counts prior to 1997 were not significantly correlated with the other methods. probably due to unrepresentative spatial sampling. A comparison of the aerial and pellet group counts in 2002 and 2006, showed that the average defecation rate was estimated at approximately 14 pellet groups per day per moose. Our results show the importance of having representative spatial sampling in pellet group surveys and indicate that hunter observations can be a useful tool for estimating long-term population trends even in moderately sized areas.
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| 6. |
- Ericsson, Göran, et al.
(författare)
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Willingness to pay (WTP) for wolverine Gulo gulo conservation
- 2007
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Ingår i: Wildlife Biology. - 0909-6396 .- 1903-220X. ; 13:Suppl. 2, s. 2-12
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Tidskriftsartikel (refereegranskat)abstract
- Knowledge about people’s willingness to pay (WTP) for conservation efforts is becoming increasingly important for natural resource management. We used a mail survey with four contacts to 11,418 people, aged 16-65, to investigate how much and why Swedes were willing to pay for wolverine Gulo gulo conservation. With the restricted distribution of European wolverines, Sweden has a key role in their management. We found that Swedes were least likely to support wolverine conservation efforts compared to wolves Canis lupus, lynx Lynx lynx and brown bears Ursus arctos. The amount varied between 965 and 1,233 SEK per person. Of the national representative control group, 47% expressed willingness to pay an average of 1,253 SEK per person. We found that in densely populated urban municipalities with a high proportion of university educated, high female-to-male ratio, positive attitude to the European monetary union (EMU), and a high income, people were more positive towards paying for wolverine conservation. The presence of wolves, but not the presence of any of the other large carnivores, was negatively related to peoples’ WTP for wolverine conservation. This indicates that the presence and related experience of wolves might be the principal driver of people’s perception of all large carnivores, including wolverines.
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| 7. |
- Nordström, Jonas, et al.
(författare)
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Can supplemental feeding of red foxes Vulpes vulpes increase roe deer Capreolus capreolus recruitment in the boreal forest?
- 2009
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Ingår i: Wildlife Biology. - : Wiley. - 0909-6396 .- 1903-220X. ; 15, s. 222-227
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Tidskriftsartikel (refereegranskat)abstract
- Red fox Vulpes vulpes predation on roe deer Capreolus capreolus fawns is regarded as a very important factor affecting recruitment of roe deer. Therefore from a hunting management perspective, it is of interest to find efficient ways to reduce predation. Because predator removal during Summer is highly controversial and banned by law in Scandinavia, supplemental feeding of red foxes during the short, critical fawning period of roe deer has been proposed as a means to relieve predation on fawns. We performed a two-year study of providing red fox vixens with food, supplied as close to active dens as possible, and monitored recruitment of radio-marked roe deer in the vicinity of these dens at a realistic management scale (i.e. the size of a large hunting area; similar to 65 km(2)). Even though red foxes found and consumed the food Supplied, we found no tendency towards increased recruitment of roe deer. We conclude that supplemental feeding of red foxes during the fawning period is not a Solution to this management problem, at least not at the chosen management scale and with the current red fox predation levels.
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| 8. |
- Olsson, Mattias, 1974-, et al.
(författare)
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Effects of highway fencing and wildlife crossings on moose Alces alces movements and space use in southwestern Sweden
- 2008
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Ingår i: Wildlife Biology. - 0909-6396 .- 1903-220X. ; 14:1, s. 111-117
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Tidskriftsartikel (refereegranskat)abstract
- Use of exclusion fencing is an effective method to reduce moose-vehicle collisions, and exclusion fences are commonly erected along Swedish highways. However, exclusion fences may pose a threat to the viability of wildlife populations because they serve as barriers to individual movements and may limit accessibility to resources. Various types of wildlife crossings intended to reduce road-kills and increase habitat connectivity across fenced highways have been constructed throughout the world. However, few studies have evaluated the effectiveness of these crossing structures with respect to movements before, during and after construction of highways and exclusion fencing. We studied movements of 24 GPS-collared moose Alces alces before, during and after an existing two-lane road was reconstructed to a fenced four-lane highway with three wildlife crossings designed for moose. We recorded 135 movements across the highway during 8,830 moose-monitoring days. Of these, 47 occurred before the construction began, 76 occurred during the construction, and 12 occurred after the highway was fenced. All movements registered after the fencing occurred across two of the three wildlife crossings. The average number of highway crossings per moose-day decreased by 67-89% after fencing. The number of moose-vehicle collisions decreased after the exclusion fencing, but the fenced highway served as a barrier to moose movements even though three wildlife crossings were created. Thus, exclusion fencing may reduce moose mortality and provide safer conditions for automobile travellers, but the fencing may have a negative impact on moose accessibility to resources, gene flow and recolonisation rates.
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| 9. |
- Wallgren, Märtha, et al.
(författare)
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Wildlife community patterns in relation to landscape structure and environmental gradients in a Swedish boreal ecosystem
- 2009
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Ingår i: Wildlife Biology. - : Wiley. - 0909-6396 .- 1903-220X. ; 15, s. 310-318
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Tidskriftsartikel (refereegranskat)abstract
- Many environmental patterns that may have profound effects on wildlife communities occur at the landscape scale, e.g. habitat fragmentation, human demography and distribution of various resources. In order to understand how alterations of such patterns could influence e.g. wildlife species occurrences and community composition, it is important to first study these relationships empirically and at the appropriate scale. We surveyed the wildlife community in a boreal ecosystem in central Sweden using pellet group counts, while walking 'wildlife triangles'. Our main aim was to investigate how the distribution of medium- and large-sized wild mammals and large-sized forest birds were affected by environmental variables at the landscape scale. In 2001-2003, pellet groups of mammals and forest birds were counted on 211 triangular routes with a perimeter of 4+4+4 km. The pellet groups which had accumulated after leaf fall were counted in spring. The environmental properties of each triangle, including information on latitude, altitude, infrastructure, land cover, forest type and forest stage, were determined using GIS maps. Statistical analyses involved mainly ordination (Principal Component Analysis, PCA). Significant environmental variables explaining the wildlife community composition and distribution in the boreal ecosystem were altitude, clear-felling and infrastructure. Our conclusion, however, is that most boreal mammal and forest bird species are habitat generalists and show little spatial pattern in distributions at the landscape scale. This indicates that habitat selectiveness probably occurs at a local scale in the boreal forest. Ultimately, our conclusion provides important direction for e.g. conservation measures and wildlife management.
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| 10. |
- Arzel, Céline, et al.
(författare)
-
Average mass of seeds encountered by foraging dabbling ducks in western Europe
- 2007
-
Ingår i: Wildlife Biology. - : Nordic Council for Wildlife Research. - 0909-6396. ; 13:3, s. 328-336
-
Tidskriftsartikel (refereegranskat)abstract
- Many dabbling ducks Anas spp. are largely granivorous, consuming a variety of seeds chiefly from aquatic plants. To assess the relative value and carrying capacity of wetlands for dabbling ducks, species-specific information about seed mass is needed, but it is still largely missing or scattered in the literature. By combining weights of seeds collected in the field with a literature review, we provide a reference table for seed mass of 200 western European plant taxa frequently encountered by foraging dabbling ducks. Seeds collected in the field were sampled in microhabitats and at depths at which ducks were observed to forage, and study sites represent wintering, staging as well as breeding areas within a flyway in western Europe. When combined with calorimetric data, the present reference table will aid managers and scientists in assessing the importance of seed food resources at different sites and during different parts of the annual cycle.
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