| 1. |
- Olsson, Ola, et al.
(författare)
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Predicting the distribution of a suitable habitat for the white stork in Southern Sweden: identifying priority areas for reintroduction and habitat restoration
- 2009
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Ingår i: Animal Conservation. - : Wiley. - 1469-1795 .- 1367-9430. ; 12:1, s. 62-70
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Tidskriftsartikel (refereegranskat)abstract
- The loss of wetlands and semi-natural grasslands throughout much of Europe has led to a historic decline of species associated with these habitats. The reinstatement of these habitats, however, requires spatially explicit predictions of the most suitable sites for restoration, to maximize the ecological benefit per unit effort. One species that demonstrates such declines is the white stork Ciconia ciconia, and the restoration of habitat for this flagship species is likely to benefit a suite of other wetland and grassland biota. Storks are also being reintroduced into southern Sweden and elsewhere, and the a priori identification of suitable sites for reintroduction will greatly improve the success of such programmes. Here a simple predictive habitat-use model was developed, where only a small but reliable presence-only dataset was available. The model is based on the extent and relative soil moisture of semi-natural pastures, the extent of wetlands and the extent of hayfields in southern Sweden. Here the model was used to predict the current extent of stork habitat that is suitable for successful breeding, and the extent of habitat that would become suitable with moderate habitat restoration. The habitat model identifies all 10 occupied nesting sites where breeding is currently successful. It also identifies similar to 300 km(2) of habitat that is predicted to be suitable stork habitat, but that is presently unused; these sites were identified as potential areas for stork reintroduction. The model also identifies over 100 areas where moderate habitat restoration is predicted to have a disproportionate effect (relative to the restoration effort) on the area of suitable habitat for storks; these sites were identified as priorities for habitat restoration. By identifying areas for reintroduction and restoration, such habitat suitability models have the potential to maximize the effectiveness of such conservation programmes.
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| 2. |
- Björklund, Mats, et al.
(författare)
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A demo-genetic analysis of a recovering population of otters in central Sweden
- 2008
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Ingår i: Animal Conservation. - : Wiley. - 1367-9430 .- 1469-1795. ; 11:6, s. 529-534
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Tidskriftsartikel (refereegranskat)abstract
- We performed a demo-genetic population viability analysis on a recovering population of otters Lutra lutra in Central Sweden, using data on population size, survival and genetic data from microsatellites. Population data were obtained from genotyping faeces. At present, the size and genetic variability of the population is increasing. We found that survival to first reproduction was the most crucial demographic parameter, and that even slight changes downward in this parameter, might lead to a declining population trajectory. Human factors that can affect mortality are traffic, fishing equipment and traps, and we argue that efforts to minimize road kills by means of safe passages as well as careful fishing efforts in streams and lakes would reduce the risk of extinction. In general, even though the population is now growing and has no inbreeding problem, its small abundance could make it vulnerable to chance events and environmental perturbations.
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| 3. |
- Champagnon, Jocelyn, et al.
(författare)
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Assessing the genetic impact of massive restocking on wild mallard
- 2013
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Ingår i: Animal Conservation. - : Wiley-Blackwell. - 1367-9430 .- 1469-1795. ; 16:3, s. 295-305
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Tidskriftsartikel (refereegranskat)abstract
- Captive-bred mallards Anas platyrhynchos have been released for hunting purposes at a very large scale in Europe since the mid-1970s. In spite of a potential genetic impact, the actual contribution of restocked mallards to the genome of the target population has received little attention. The genetic structure of modern wild mallards in the Camargue, Southern France, was assessed from two samples: one originating from shot birds in hunting bags and one from presumed wild ducks captured alive in a hunting-free reserve. Reference samples originated from five mallard farms, as well as from museum samples collected before the mid-1970s (i.e. before massive mallard releases started). Our results revealed that the genetic signature of wild wintering mallards has not changed significantly because museum and presumed wild samples from the Camargue hunting-free nature reserve were genetically similar, and clearly differentiated from the farm mallards. This suggests that mallard releases in the Camargue or elsewhere inFrance, although massive, have not actually translated into complete admixture of wild and captive genomes, most likely due to low survival of released birds once in the wild. Nevertheless, although genetic introgression of the wild population by captive-bred was contained, we found significant rates of hybridization between wild and captive-bred mallards in modern samples. This result suggests that long-term releases of captive-bred mallards, if carried on at such large scale, could compromise irreversibly the genetic structure and composition of European mallards. This work contributes to fill in the gap on the monitoring of the genetic consequences of large-scale game releases for exploitation.
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| 4. |
- Höglund, Jacob, et al.
(författare)
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Genetic structure among black grouse in Britain : implications for designing conservation units
- 2011
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Ingår i: Animal Conservation. - : Wiley. - 1367-9430 .- 1469-1795. ; 14:4, s. 400-408
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Tidskriftsartikel (refereegranskat)abstract
- Black grouse in Britain have faced contraction of their range and have declined in numbers during the recent decades. As such, the species is a conservation concern in the UK. In order to aid conservation decisions, the terms Evolutionary Significant Unit (ESU) and Management Unit (MU) have been proposed. An ESU is an independently evolving evolutionary lineage defined by being reciprocally monophyletic for mitochondrial alleles, and which is significantly different from other lineages with regard to nuclear alleles, whereas an MU is operationally defined by only the latter criterion. Using mitochondrial sequences and nuclear microsatellite loci, we failed to find evidence that British black grouse is an ESU. However, British black grouse are sufficiently different from continental black grouse both with respect to mitochondrial and nuclear data to regard them as a separate MU. Furthermore, we present genetic data which suggest that British black grouse presently occur in what are probably three demographically independent units (roughly corresponding to Wales, northern England/southern Scotland and northern Scotland), which are genetically differentiated. The two southern units (Wales and northern England/southern Scotland) have lower genetic diversity and show signs of having lost genetic variability
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| 5. |
- Meijer, Tomas, et al.
(författare)
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Estimating population parameters in a threatened arctic fox population using molecular tracking and traditional field methods
- 2008
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Ingår i: Animal Conservation. - : Wiley-Blackwell. - 1469-1795 .- 1367-9430. ; 11:4, s. 330-338
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Tidskriftsartikel (refereegranskat)abstract
- Comprehensive population parameter data are useful for assessing effective conservation actions. The Fennoscandian arctic fox Alopex lagopus is critically endangered and the population size is estimated at 120 individuals that are fragmented into four isolated populations. Here, we use molecular tracking and visual observations to estimate population size and survival in one of the populations on the Swedish mountain tundra during a year of low food availability. We collected 98 arctic fox faecal samples during the winter of 2006 and recorded visual observations of ear-tagged individuals during the summer of 2005 and 2006. The faecal samples were analysed for variation in nine microsatellite loci and matched to the genetic profiles of previously ear-tagged individuals from 2001 to 2005. During winter 2006, the minimum number alive was 12 individuals using visual observations, 30 using molecular tracking and 36 by combining the datasets. Population size was estimated through mark–recapture for the molecular tracking and visual observation datasets and through rarefaction analyses for molecular tracking data. The mark–recapture estimate for visual observations was uninformative due to the large confidence interval (CI) (i.e. 6–212 individuals). Based on the molecular tracking dataset combined with the minimum number alive for visual observations and molecular tracking, we concluded a consensus population size of 36–55 individuals. We also estimated the age-specific finite survival rate during 1 year (July 2005 to July 2006) by combining molecular tracking with visual observations. Juvenile survival on a yearly basis was 0.08 (95% CI 0.02–0.18) while adults had a survival of 0.59 (95% CI 0.39–0.82). Juveniles displayed a lower survival than the adults during autumn (P<0.01) whereas no age-specific survival difference during spring was found. The risk of negative effects due to the small population size and low juvenile survival is accordingly considerable.
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| 6. |
- Norén, Karin, et al.
(författare)
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Farmed arctic foxes on the Fennoscandian mountain tundra : implications for conservation
- 2009
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Ingår i: Animal Conservation. - : Wiley. - 1367-9430 .- 1469-1795. ; 12:5, s. 434-444
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Tidskriftsartikel (refereegranskat)abstract
- Hybridization between wild and captive-bred individuals is a serious conservation issue that requires measures to prevent negative effects. Such measures are, however, often considered controversial by the public, especially when concerning charismatic species. One of the threats to the critically endangered Fennoscandian arctic fox Alopex lagopus is hybridization with escaped farm foxes, conveying a risk of outbreeding depression through loss of local adaptations to the lemming cycle. In this study, we investigate the existence of escaped farm foxes among wild arctic foxes and whether hybridization has occurred in the wild. We analysed mitochondrial control region sequences and 10 microsatellite loci in samples from free-ranging foxes and compared them with reference samples of known farm foxes and true Fennoscandian arctic foxes. We identified the farm fox specific mitochondrial haplotype H9 in 25 out of 182 samples, 21 of which had been collected within or nearby the wild subpopulation on Hardangervidda in south-western Norway. Genetic analyses of museum specimens collected on Hardangervidda (1897–1975) suggested that farm fox genotypes have recently been introduced to the area. Principal component analysis as well as both model- and frequency-based analyses of microsatellite data imply that the free-ranging H9s were farm foxes rather than wild arctic foxes and that the entire Hardangervidda population consisted of farm foxes or putative hybrids. We strongly recommend removal of farm foxes and hybrids in the wild to prevent genetic pollution of the remaining wild subpopulations of threatened arctic foxes.
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| 7. |
- van Toor, Mariëlle L., et al.
(författare)
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Integrating sex‐specific habitat use for conservation using habitat suitability models
- 2011
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Ingår i: Animal Conservation. - : John Wiley & Sons. - 1367-9430 .- 1469-1795. ; 14:5, s. 512-520
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Tidskriftsartikel (refereegranskat)abstract
- Divergent habitat utilization and niche partitioning can cause high degrees of ecological specialization even in generalist species. For example, sex‐specific specialization results in differential habitat use, which, if neglected in monitoring studies, can lead to biased estimates of population sizes. However, many widely used methods of population monitoring such as bioacoustical surveys of echolocating bats cannot take such demographic differences into account, due to methodological limitations. Here, we use ecological niche factor analysis (ENFA) to derive habitat suitability maps (HSMs) of male and female parti‐coloured bat Vespertilio murinus using previously published radio‐tracking data. The ENFA revealed that males and females were highly specialized and ecologically segregated. Accordingly, we found that significantly more high‐quality habitats were available for males than for females, with no spatial overlap between sexes. The HSMs allowed us to estimate the skew in the distribution of the sexes in space. Our approach provides a way to estimate intra‐species spatial segregation and consequently generate a more accurate prediction of effective population size and niche requirements of vulnerable species. This study also highlights the importance of making geographic and environmental data, as well as animal occurrence and movement data publicly available for the benefit of conservation efforts.
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| 8. |
- Aronsson, Malin, et al.
(författare)
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Mismatch between goals and the scale of actions constrains adaptive carnivore management: the case of the wolverine in Sweden
- 2017
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Ingår i: Animal Conservation. - : Wiley. - 1367-9430 .- 1469-1795. ; 20, s. 261-269
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Tidskriftsartikel (refereegranskat)abstract
- Efficient conservation of wide-ranging carnivores requires that adaptive management consider the varying ecological and societal conditions within the entire range of a population. In northern Europe, large carnivore management has to balance carnivore conservation and maintaining the indigenous reindeer-herding culture. Wolverine Gulo gulo monitoring and management in Sweden is currently focused on alpine reindeer husbandry areas where wolverine abundance and associated depredation conflicts have been highest. However, this focus ignores a potential southwards population expansion because current monitoring relies on snow-based tracking methods that are not applicable outside northern alpine areas. Thus, in this study we: (1) used available monitoring data from 1996 to 2014 in Sweden to assess wolverine distribution trends in relation to national management goals, and (2) evaluate the current monitoring protocol against the use of camera stations as an alternative, snow-independent, method for detecting wolverine presence at the southern periphery of its distribution. We show that the wolverine population in Sweden has expanded considerably into the boreal forest landscape, and colonized areas without reindeer husbandry and persistent spring snow cover. The latter indicates a less strict relationship between wolverine distribution and snow cover than previously hypothesized. Current management continues to use a monitoring protocol that is only adapted to high-conflict alpine areas, and is not adapting to changing conditions in the population range, which creates a problematic scale mismatch. Consequently, national management decisions are currently based on incomplete population information, as roughly a third of wolverine's range is not included in official population estimates, which could have detrimental consequences for conflict mitigation and conservation efforts. This illustrates that an important key to successful carnivore conservation is flexible management that considers the entire range of conditions at the appropriate regional and temporal scales under which carnivores, environment and people interact.
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| 9. |
- Betzholtz, Per-Eric, et al.
(författare)
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Colour pattern variation can inform about extinction risk in moths
- 2017
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Ingår i: Animal Conservation. - : Wiley-Blackwell. - 1367-9430 .- 1469-1795. ; 20:1, s. 72-79
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Tidskriftsartikel (refereegranskat)abstract
- Theory posits that species with inter-individual variation in colour patterns should beless vulnerable to extinction, compared with species that do not vary in colour. Toevaluate this prediction, we explored whether differences in colour pattern diversitywas associated with extinction risk, using red-list status for more than 350 species ofnoctuid moths in Sweden. We also evaluated six other species characteristics thathave been proposed to influence extinction risk namely: host plant niche breadth,habitat type, area of occupancy, body size, overwintering life-history stage and lengthof flight activity period. We found that species with variable colour patterns hadreduced extinction risk overall compared with species having non-variable colourpatterns, and that this difference was pronounced more strongly among species havingsmaller areas of occupancy. There were also significant associations with hostplant niche breadth and habitat type, extinction risk being lower on average in polyphagousspecies and in generalist species that occupied different habitat types. Thesefindings represent the first evidence for insects that variable colouration is associatedwith reduced extinction risks. Information on colour pattern variation is readily availablefor many taxa and may be used as a cost-effective proxy for endangerment inthe work of halting national and global biodiversity loss.
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| 10. |
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