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Genetic structure of North American wolverine (Gulo gulo) populations
Abstract
Wolverines (Gulo gulo) are found in low densities throughout their circumpolar distribution. They are also potentially susceptible to human-caused population fragmentation (development, recreation and fur harvesting). The combination of these factors has contributed to this species being listed as having either vulnerable or endangered status across much of its current range. The effects of inherently low densities and anthropogenic pressures on the genetic structure and variation of wolverine populations are, as yet, unknown. In this study, 461 individuals were typed at 12 microsatellite loci to investigate the population genetic structure of wolverines from north-western Alaska to eastern Manitoba. Levels of gene flow and population differentiation among the sampled regions were estimated via a genotype assignment test, pairwise F(ST), and two genetic distance measures. Our results suggest that wolverine populations from southernmost regions, in which anthropogenic factors are strongest, revealed more genetic structuring than did northern populations. Furthermore, these results suggest that reductions in this species' range may have led to population fragmentation in the extreme reaches of its southern distribution. The continued reduction of suitable habitat for this species may lead to more populations becoming isolated remnants of a larger distribution of northern wolverines, as documented in other North American carnivore species.
... Such is the case of many mesocarnivores species, that despite their ecological importance, they have been understudied in many genetic aspects [17] [19] [20]. Nonetheless, there are studies in mesocarnivores that have found genetic structure in a variety of ecological conditions, such as American mink (Neovison vison; [13]), coyotes (Canis latrans; [11]), fishers (Martes pennanti; [21] [22]), Eurasian otters (Lutra lutra; [23] [24]), Neotropical otters (Lontra longicaudis; [25]), Tasmanian devils (Sarcophilus laniarius; [15]), and wolverines (Gulo gulo; [26]). ...
... In addition, female migration occasionally occurs, despite the aggressions from the other members of the band due to the absence of kinship [27] [31] [39]. Still, our data suggests that the mating system and overlapping of band and home ranges of males [28] [13], Eurasian otters [23], fishers [21], wolverines [26], and ring-tailed coatis [35]. The ring-tailed coati provides an interesting comparison. ...
... The genetic differentiation between the N. narica populations recorded in this study is probably a result of limited gene flow, due to the combination of the demographic decline [45], dispersal capabilities of the species [40], and the isolating effects of the geographical barriers [6] [47]. That pattern has been observed for other carnivore species [21] [26]. [95]. ...
Coatis (Procyonidae; 𝘕𝘢𝘴𝘶𝘢) are considered the only truly social mesocarnivore mammals in Neotropical forests. In Mexico, white-nosed coatis (𝘕𝘢𝘴𝘶𝘢 𝘯𝘢𝘳𝘪𝘤𝘢) are suspected to have undergone population reduction due to habitat loss and fragmentation and led to a lack of genetic adaptability and genetic isolation throughout its range. We examined patterns of genetic diversity and connectivity of five populations of Nasua narica distributed throughout Mexico (𝘯 = 60) by sequencing an ≈ 800 bp fragment of the mitochondrial cytochrome-b gene and also by screening 12 microsatellite loci. We found moderate to high levels of genetic variability for both genetic markers. We recorded twenty-two different cytochrome-b haplotypes throughout the 5 sampled areas and found that each of the sampled population of white-nosed coatis in Mexico harbors unique haplotypes and only three haplotypes were shared among two different populations that were closer geographically. All populations had high haplotype diversity (𝘩) (0.968 ± 0.008 (SD)) but lower levels of
nucleotide diversity (π) of 0.007 ± 0.001 (SD). All microsatellite loci were polymorphic in all of the populations and the mean number of alleles per locus was 5.033 ± 1.545 (SD) with expected (H🇪 ) and observed (H🇴 ) heterozygosity values of 0.774 and 0.664, respectively. However, low Wright F statistic values suggest the existence of a reduced heterozygosity (𝘍𝘚𝘛 = 0.203, 𝘍𝘐𝘚 = 0.134 and 𝘍𝘐𝘛 = 0.310). Significant differences between the five populations confirmed isolation by distance, which suggests genetic structure among five subpopulations.
... Neutral genetic studies for wolverines suggest that female philopatry most likely accounts for the geographical genetic structure of this species. Mitochondrial (mtDNA) genetic structure was much stronger [39][40][41] relative to the genetic structure observed for neutral microsatellite loci across a broad geographic range, reflecting the long distance dispersal capacity for males [39][40][41][42][43][44]. Both mtDNA and microsatellites showed higher genetic structure towards the eastern and southern peripheries of the wolverine's distribution in North America [41,42], which is hypothesized to reflect a historical colonization incursion from west to east during the Holocene [45]. ...
... This was accomplished by contrasting spatial patterns of MHC and neutral microsatellite markers to account for demographic processes on MHC variation, while using wolverines from a region in eastern Russia as a reference point for comparisons. We expected to find higher diversity and similar MHC variation in the core of the wolverine distribution as a matter of extensive gene flow [40,43], with stronger MHC structure towards the eastern distribution from the combination of limited gene flow and increased drift in the smaller eastern populations [41,42,44]. Further, we expected the varying spatial MHC structure to be stronger than the structure from microsatellite loci if fluctuating selection played a major role shaping the distribution of MHC variation (as in other studies e.g., [7][8][9][10]). ...
... Samples used in this study were a subset of those previously analyzed by Kyle & Strobeck [42,43] and Zigouris et al. [41] using neutral microsatellite loci and mitochondrial DNA control region. We selected a total of 269 individuals from nine regions: eastern Russia (RU), NU, YK, NWT, BC, AB, SK, western MB and western ON. ...
Elucidating the adaptive genetic potential of wildlife populations to environmental selective pressures is fundamental for species conservation. Genes of the major histocompatibility complex (MHC) are highly polymorphic, and play a key role in the adaptive immune response against pathogens. MHC polymorphism has been linked to balancing selection or heterogeneous selection promoting local adaptation. However, spatial patterns of MHC polymorphism are also influenced by gene flow and drift. Wolverines are highly vagile, inhabiting varied ecoregions that include boreal forest, taiga, tundra, and high alpine ecosystems. Here, we investigated the immunogenetic variation of wolverines in Canada as a surrogate for identifying local adaptation by contrasting the genetic structure at MHC relative to the structure at 11 neutral microsatellites to account for gene flow and drift. Evidence of historical positive selection was detected at MHC using maximum likelihood codon-based methods. Bayesian and multivariate cluster analyses revealed weaker population genetic differentiation at MHC relative to the increasing microsatellite genetic structure towards the eastern wolverine distribution. Mantel correlations of MHC against geographical distances showed no pattern of isolation by distance (IBD: r =-0.03, p = 0.9), whereas for microsatellites we found a relatively strong and significant IBD (r = 0.54, p = 0.01). Moreover , we found a significant correlation between microsatellite allelic richness and the mean number of MHC alleles, but we did not observe low MHC diversity in small populations. Overall these results suggest that MHC polymorphism has been influenced primarily by balancing selection and to a lesser extent by neutral processes such as genetic drift, with no clear evidence for local adaptation. This study contributes to our understanding of how vulnerable populations of wolverines may respond to selective pressures across their range.
... The analysis of nuclear loci (Wilson et al. 2000;Strobeck 2001, 2002) revealed low levels of genetic structuring in North American wolverines. Therefore, Kyle and Strobeck (2001) suggested that the wolverines from northern Canada represent a single, panmictically breeding population. Contrary to the low level of genetic structuring resulted from the study of nuclear loci, a high degree of genetic differentiation among North American wolverines was detected in mitochondrial DNA. ...
... In Eurasia, wolverines were not genetically differentiated between Sweden and Norway, neither between Mongolia and eastern Siberia. These data are in contrast to the nearly panmictic structure observed in northwestern North America based on nuclear microsatellites (Wilson et al. 2000, Kyle and Strobeck 2001, 2002 but largely support the nuclear DNA separation of contemporary Manitoba and Ontario wolverines from northern populations. Historic samples from the extirpated eastern population of Quebec/Labrador displayed a genetic similarity to the contemporary Ontario wolverines. ...
... However, similar studies done on larger, more connected populations in Alaska and Canada did not detect such evidence of subpopulations (Kyle & Strobeck 2001. This suggests wolverines are sensitive to habitat fragmentation and human disturbance, and without adequate connectivity are prone to population segregation. ...
... This suggests wolverines are sensitive to habitat fragmentation and human disturbance, and without adequate connectivity are prone to population segregation. Though wolverines do not appear to treat natural landscape features as dispersal barriers (Kyle & Strobeck 2001), they do, however, appear to be affected by human development and disturbance (Banci 1994;Rowland et al. 2003). ...
Dispersal is a biological imperative for many species, facilitating gene flow and influencing population dynamics. Modern landscapes are increasingly fragmented, leaving species that rely on dispersal trapped in ever shrinking areas. Measuring connectivity at the population level is difficult using traditional tracking methods, especially for species that are rare or cryptic, but important for both theoretical and applied questions relating to animal movement.
Using genetic monitoring data collected from 2004 to 2018, SNP (single nucleotide polymorphism) genotyping was used to reconstruct pedigrees of wolverines from the whole of Sweden, Norway, and Finland. The resulting pedigree contained over 900 individuals, and six generations. These family triads were then used to identify patterns of natal dispersal for offspring, and breeding related movement between known mated pairs. The results reveal a metapopulation of several reproductive cores spread over three countries, with animals moving across borders in order to breed and disperse. Patterns of movement on this scale identify sources and sinks across the entire range, with little ambiguity due to sample size or study site. To achieve favourable conservation status, management scales should reflect the scales at which populations function.
... The allelic and genotypic frequencies in hares were not homogeneous across the Yukon study area, suggesting significant genetic structure, and generally followed a pattern of decreasing similarity with increasing geographic distance. This pattern of isolation by distance has also been observed at comparable scales in other small and medium-sized mammals such as the whitetoothed shrew (Favre et al. 1997), Alpine marmot (Marmota marmota, Goossens et al. 2001), wolverine (Gulo gulo, Kyle and Strobeck 2001), pine marten (Martes americana, Kyle et al. 2000), northern Idaho ground squirrel (Spermophilus brunneus brunneus, Gavin et al. 1999), and house mouse (Mus musculus, Dallas et al. 1995). By contrast, isolation by distance was not detected in the European rabbit (Fuller et al. 1996, collared lemming (Ehrich et al. 2001) and white-footed mouse (Peromyscus leucopus, Mossman & Waser 2001). ...
... Southern populations have been hypothesized to have different dynamics from those in the north, potentially due to greater habitat fragmentation and the presence of more facultative predators (see Hodges 2000b for a review). Habitat fragmentation can influence genetic structure in small mammals (Gaines et al. 1997) and may be linked to genetic differences between northern and southern carnivore populations in western North America (Paetkau et al. 1998, Kyle et al. 2000, Kyle & Strobeck 2001. Further investigation into the demographic and genetic differences among northern and southern hare populations is needed. ...
In this thesis, I used seven microsatellite DNA markers to investigate three levels of hare population structure: mating structure, social structure and geographic structure.
... The genetic analyses of Kyle and Strobeck (2001) Isolation and subsequent loss of genetic variation may be a concern if connectivity is lost between current populations in Idaho, Montana, and Wyoming. Also, at this time it is not known if wolverines in the contiguous U.S. can persist without immigration of individuals from Canada (Banci 1994). ...
... Recent genetic studies (Kyle and Strobeck 2001;A. Magoun, Alaska Department of Fish and Game, personal communication) indicate that wolverines in the contiguous U.S. may have relatively low genetic diversity, which could be a result of increasing separation from the main continental center of occurrence in Canada. ...
... Although formerly widespread throughout the Holarctic, the wolverine range has become smaller and more fragmented in both Eurasia and North America (Fisher et al., 2022;Landa et al., 2000;Tumanov & Kozhechkin, 2012). This has had a significant impact on the genetic structure and diversity of wolverine populations, both globally and locally (Krejsa et al., 2021;Kyle & Strobeck, 2001Lansink et al., 2022;Zigouris et al., 2013). For example, the current division into two populations in Fennoscandia (mainly in Norway, Sweden, and Finland) likely emerged after decades of persecution need better connectivity to the other Eurasian populations to ensure gene flow and long-term persistence. ...
Aim: Our aim was to assess the population structure, genetic diversity and demographic history of the wolverine (Gulo gulo) throughout its entire Eurasian range. Additionally, we aimed to contextualize and put into perspective the state of the endangered Fennoscandian population by emphasizing its connectivity to other populations. Location: The main study area covered most of the Eurasian wolverine range, with samples from Finland, Russia, Kazakhstan and Mongolia. Methods: Using a 495 bp fragment of the mitochondrial DNA control region and a frequently used set of 14 microsatellite markers on an extensive dataset of samples, we assessed the population structure, genetic diversity, and demographic history of wolverines with a variety of population genetic analyses. Results: According to both nuclear and mitochondrial genetic markers, Eurasian wolverines exhibit substructure, with the most distinct population located in Fennoscandia. The Fennoscandian population has undergone a genetic bottleneck, likely influencing its genetic diversity, which is notably the lowest in Eurasia. Genetic diversity in the rest of Eurasia gradually rises towards the central part of the range and decreases again in the east, although not as significantly as in the west. Main Conclusions: This study reveals the population structure of wolverines across Eurasia and provides direction for allocating conservation efforts to sustain a diverse and connected wolverine population. While most of the Eurasian populations seem to be well-connected and genetically diverse, the Fennoscandian wolverines may
... With an efficient gradient oracle in hand for the loss function in Problem 1, we test a gradient based optimization approach on both synthetic and real genetic data. Real genetic data is obtained for the North American wolverine (Gulo gulo) from Kyle and Strobeck (2001), which provides F ST values for Figure 2: Relative error between recovered parameters and true parameters for synthetic data experiments with different numbers of nodes sampled N and noise standard deviationσ. Parameter recovery improves with more samples (i.e., more locations with genetic similarity data), and generally with less noise (i.e., more highly correlated resistance and genetic data). ...
The problem of inferring unknown graph edges from numerical data at a graph's nodes appears in many forms across machine learning. We study a version of this problem that arises in the field of landscape genetics, where genetic similarity between organisms living in a heterogeneous landscape is explained by a weighted graph that encodes the ease of dispersal through that landscape. Our main contribution is an efficient algorithm for inverse landscape genetics, which is the task of inferring this graph from measurements of genetic similarity at different locations (graph nodes). Inverse landscape genetics is important in discovering impediments to species dispersal that threaten biodiversity and long-term species survival. In particular, it is widely used to study the effects of climate change and human development. Drawing on influential work that models organism dispersal using graph effective resistances (McRae 2006), we reduce the inverse landscape genetics problem to that of inferring graph edges from noisy measurements of these resistances, which can be obtained from genetic similarity data. Building on the NeurIPS 2018 work of Hoskins et al. (2018) on learning edges in social networks, we develop an efficient first-order optimization method for solving this problem. Despite its non-convex nature, experiments on synthetic and real genetic data establish that our method provides fast and reliable convergence, significantly outperforming existing heuristics used in the field. By providing researchers with a powerful, general purpose algorithmic tool, we hope our work will have a positive impact on accelerating work on landscape genetics.
... Furthermore, adjacent areas in Alaska, Northwest Territories, and British Columbia are also largely unfragmented by human infrastructure, presumably maintaining population connectivity. The lack of genetic structure between wolverine populations in Alaska and northwestern Canada supports population connectivity at large spatial scales (Kyle and Strobeck 2001;Tomasik and Cook 2005;Krejsa et al. 2021). Because much of eastern and northern Yukon is remote, and individual RTCs are large, over-harvest in the near future is unlikely in these areas. ...
Fur trapping is an important source of mortality for wolverine (Gulo gulo) in northern Canada. However, few populations are monitored for harvest sustainability. An examination of harvest data can be useful to identify areas of concern and direct appropriate management interventions. We used 27 years of harvest data (1988–2014) to examine patterns of wolverine harvest in the Yukon (Canada), where trapping permits are spatially explicit and there are no quotas. We identify spatiotemporal patterns in estimated harvest density, and trapping behavior by fur trappers. We also examined estimated harvest rates and availability of harvest refugia to evaluate if harvest was sustainable. The mean annual harvest in Yukon was 132 ± 31 wolverines, and there was no significant trend over time. Most trappers harvested wolverines infrequently, but 12% of trappers were responsible for 50% of all harvested wolverines, indicating that a small number of trappers had an influence on overall mortality. Relatively high mean annual harvest rates (≥8%) were estimated in several ecoregions in southwestern Yukon, where much of the human population and roads are concentrated. Conversely, estimated harvest rates were moderate to low (<6%) in northern and eastern Yukon, which consist largely of remote wilderness. The mean percent area without harvest was 62 ± 16%. Sustained high harvest rates in southwestern Yukon are likely supported by dispersing animals from harvest refugia. Few putative harvest refugia were formally protected; rather, unutilized trapping areas constituted temporal de facto harvest refugia. Our study points to the importance of harvest refugia, and the persistence of wilderness regions, for sustaining wolverine populations.
... Norway and Sweden's conflicting management plans confound conservation efforts. The USA's small isolated wolverine populations could be heavily dependent on immigration from Canadian source populations (Balkenhol et al., 2020;Kyle and Strobeck, 2001). However in Canada, differences in the ecology and threats to wolverine among boreal, mountain, and arctic environments makes coordinated management difficult; and currently wolverine population management differs among jurisdictions with little federal coordination. ...
Wolverines are vulnerable to multiple, widespread, increasing forms of human activity so have become an indicator of conservation success or failure for northern ecosystems. Logistically difficult to research, the last two decades have seen marked changes in technology yielding new insights. We reviewed and synthesized this recent research and asked: what are the known drivers of wolverine populations and distribution, is there consensus on mechanisms for populations dynamics, and how can this knowledge inform wolverine conservation? From 156 peer-reviewed papers we observed wolverine research varies geographically in volume, and especially in focus. Most papers arose from Canada and the USA, whereas Scandinavia led Palearctic efforts; large gaps exist outside that region. DNA and telemetry are the most common modes of inquiry, with camera traps increasing recently. In Scandinavia coordinated long-term monitoring programs have yielded substantial information; the Nearctic relied on stand-alone research until the recent USA multi-state monitoring project, and Canada lacks such coordination. Globally, protected areas are important for wolverine conservation, but effective landscape and population management in the working land base is vital. The dual drivers of climate and landscape change manifest across wolverines’ range, but past and current correlation between them remains a confound. Coordinated continental-scale analyses across gradients of development and climate change are needed to parse apart drivers of declines at macroecological scales, to inform effective conservation decisions.
... Our estimate of population subdivision based on heterozygosity (F ST = 0.17) was significant, but still within the range reported in most wolverine studies across North America (i.e., F ST = 0.00-0.22- Kyle and Strobeck 2001, 0.00-0.20-Kyle and Strobeck 2002, 0.06-0.17-Cegelski ...
The wolverine (Gulo gulo) is a Holarctic species found in North America primarily across the boreal forest, the subarctic, and along the Pacific coast, including Vancouver Island (VI), British Columbia. While wolverines on VI are rare and possibly extirpated, they have been previously described as a unique subspecies, G. g. vancouverensis, distinct from G. g. luscus from the mainland of North America. However, the validity of the VI subspecies is contentious, with conflicting results from studies of skull morphology. Here, we used molecular analyses to characterize the genetic diversity of the VI population and resolve this taxonomic debate to assist with conservation priorities. Historical DNA of VI wolverines was obtained from museum specimens, amplified at 16 nuclear microsatellite loci, and sequenced at the mitochondrial D-loop control region to compare with wolverines from mainland British Columbia. The VI population had lower allelic richness and was fixed for a single common mtDNA haplotype. Bayesian and non-Bayesian assignments using microsatellites generally revealed admixture across populations, implying allele frequencies between the VI and mainland populations were not significantly different. Hence, both types of genetic markers showed little evolutionary divergence between VI and the mainland population. Combined, these results do not provide evidence of significant genetic distinction for VI wolverines, nor support the subspecific classification. Immediate conservation efforts should focus on estimating population size, while future conservation planning can assume VI wolverines likely are not a unique genetic population and there remains the potential for natural recolonization of wolverines to VI.
... With an efficient gradient oracle in hand for the loss function in Problem 1, we test a gradient based optimization approach on both synthetic and real genetic data. Real genetic data is obtained for the North American wolverine (Gulo gulo) from [21], which provides F ST values for 6 populations living across a region in Alaska. Our goal is to understand the interplay between genetic variation in this region and the underlying landscape. ...
The problem of inferring unknown graph edges from numerical data at a graph's nodes appears in many forms across machine learning. We study a version of this problem that arises in the field of landscape genetics, where genetic similarity between populations of organisms living in a heterogeneous landscape is explained by a weighted graph that encodes the ease of dispersal through that landscape. Our main contribution is an efficient algorithm for inverse landscape genetics, which is the task of inferring this graph from measurements of genetic similarity at different locations (graph nodes). We reduced the problem to that of inferring graph edges from noisy measurements of effective resistances between graph nodes, which have been observed to correlate well with genetic similarity. Building on Hoskins et. al., we develop an efficient first-order optimization method for solving this problem. Despite its non-convex nature, extensive experiments on synthetic and real genetic data establish that our method provides fast and reliable convergence, significantly outperforming existing heuristics used in the field.
... By contrast, when fragmentation is too recent for population differences to have accumulated, or where large population size limits the power of genetic drift to create differences between populations, these tools lack power . A lack of population differentiation also limits the power of indirect genetic tools for inferring population structure, including reduced heterozygosity (Keyghobadi et al. 2005), genetic distance measures, F ST (Kyle and Strobeck 2001), or even individual-based methods, including genetic clustering (Benzecri 1973, Pritchard et al. 2000 or assignment methods , Proctor et al. 2012b. ...
Population fragmentation is stressing wildlife species worldwide. In populations with minimal genetic structure across potential fractures, detecting fragmentation can be challenging. Here we apply a relatively unused approach, genetic pedigree analysis, to detect fragmentation in the American black bear (Ursus americanus) across 2 highway corridors that are bordered by large, contiguous populations. We compared our results with movements detected through Global Positioning System (GPS) telemetry of collared bears between 2005 and 2010. We used 20-locus microsatellite genotypes to identify 104 first-order relatives (parent–offspring or full siblings) within 383 black bears, sampled between 2002 and 2012. We compared numbers of pairs of immediate relatives found on either side of 2 highways—U.S. Highway 2 in northwestern Montana, USA, and BC Highway 3 in southeastern British Columbia, Canada—with an expected rate, the mean across 22 lines parallel to each highway at 1-km intervals. We found that over similar geographic scales, dispersal was lower across the transportation corridors than adjacent areas without a highway corridor. The observed number of migrants across Highway 2 was 3, well below the confidence interval of the expected number of 15.1 migrants/available bears (95% CI = 12.2–18.0). Highway 3 had 6 migrants, compared with the expected 13.1 bears (95% CI = 10.8–15.5). None of 16 black bears wearing GPS radiocollars for 1 year crossed Highway 2, yet 6 of 18 crossed Highway 3. These results suggest that even though 33% of radiocollared black bears crossed Highway 3, there appeared to be less dispersal across the transportation corridors than across other regions in the study area. Pedigree and telemetry results were more closely aligned in the Highway 2 system, with both methods suggesting more intense fragmentation than we found along Highway 3. Our results identified pedigree analysis as another tool for investigating population fragmentation, particularly in situations where genetic differentiation is too weak to determine migration rates using individual-based methods, such as population assignment.
... The impact of humans on the natural fauna might thus be much older than is usually considered when focusing on the effects of industrialization (Martin, 2005) and recent habitat destruction (although these actions are also of great concern because they are ongoing). There is increasing evidence that current habitat fragmentation is strongly affecting the genetic structure of animal populations (Gerlach & Musolf, 2000;Kyle & Strobeck, 2001;Wang & Schreiber, 2001;Hirota et al., 2004;Keller et al., 2004). In contrast, the potential impact of more ancient anthropogenic changes on the patterns of geographical differentiation o f E u r o p e a n w i l d s p e c i e s r e m a i n s l a r g e l y undocumented. ...
The genetic structure of forest animal species may allow the spatial dynamics of the forests themselves to be tracked. Two scales of change are commonly discussed: changes in forest distribution during the Quaternary, due to glacial/ interglacial cycles, and current fragmentation related to habitat destruction. However, anthropogenic changes in forest distribution may have started well before the Quaternary, causing fragmentation at an intermediate time scale that is seldom considered. To explore the relative role of these processes, the genetic structure of a forest species with narrow ecological preferences, the edible dormouse (Glis glis), was investigated in a set of samples covering a large part of its Palaearctic distribution. Strong and complex geographical structure was revealed from the use of microsatellite markers. This structure suggests that fragmentation occurred in several steps, progressively splitting the ancestral population into peripheral isolated ones. The fact that this structure postdates post-glacial recolonization, together with dating based on microsatellite data, supports the hypothesis that the differentiation was recent, starting around 9000 years ago, and took place stepwise, possibly up to Medieval times. This complements a classic phylogeographical interpretation based on the effect of past climate change, and supports the role of anthropogenic deforestation as a trigger of recent intraspecific differentiation. © 2019 The Linnean Society of London, Biological Journal of the Linnean Society.
... Several studies, applying genetic markers, have been conducted in Europe and North America, addressing several conservation and wildlife management issues. Questions concerning the impact of reintroductions and demographic decline ( Vernesi et al, 2003); hybridization between wild and domestic populations (Beaumont et al, 2001;Randi & Lucchini, 2002) fragmentation and isolation of populations ( Kuhen et al, 2003); consequences of relocation programs and bottlenecks (Maudet et al, 2002) and the impact of anthropogenic disturbance on the genetic struc- ture of the populations (Kyle & Strobeck, 2001) have been studied using microsatellite markers. The main objective of the present study was to assess the level of structuring in the Portuguese wild boar population. ...
Abstract
Wild boar (Sus scrofa) is the most important big game species in Portugal. After a generalized decline in the recent past, the species has suffered, in the last decades, an overall increase in number of individuals and dispersion range. The large population size of this widespread species has a strong impact on natural and agricultural landscapes. To avoid conflict between human and wild boar populations, the management of this and other wildlife populations must be taken as a priority. Management and conservation of wild boar should be based on true knowledge of its population’s ecology, dynamics and biodiversity. The last issue is intimately related with the population's genetic structure and variability, which can be assessed by characterization with genetic markers.
Several studies, applying genetic markers, have been conducted in Europe and North America, addressing several conservation and wildlife management issues. Questions like the impact of reintroductions and demographic decline (Vernesi et al, 2003); hybridization between wild and domestic populations (Beaumont et al, 2001; Randi & Lucchini, 2002) fragmentation and isolation of populations (Kuhen et al, 2003); consequences of relocation programs and bottlenecks (Maudet et al, 2002) and the impact of anthropogenic disturbance over genetic structure of the populations (Kyle & Strobeck, 2001) have been studied using microsatellite markers.
The main objective of the present study was to assess the level of structuring in the Portuguese wild boar population. For the purpose, 110 blood samples were collected all over the country, from animals harvested during game events, during the hunting seasons of 2002/03 and 2003/04. Blood samples were collected in the field, in tubes containing K3EDTA and carried to laboratory were they were stored in FTA cards (Whatman®), at room temperature. The remaining portion of each sample was stored at -20ºC. When the blood is placed in FTA cards, a pre-extraction of the DNA takes place. Extracted DNA can be removed with the proper eluent. However, a re-extraction of the DNA from the bloodstains in FTA cards was performed, following the general Chelex procedure (Walsh et al, 1991).
Microsatellite analysis was performed using 6 markers (S0008, SW986, SW1129, SW1701, SW1517, SW828 - source: The USDA Supported US Pig Genome Coordination Project). The markers were amplified in multiplex PCR reactions, in the following amplification sets: set 1 - S0008, SW986, SW1129; set 2 - SW1701, SW1517, SW828. Amplification with multiplex sets (see also Souto et al, 2004) was conducted using the Quiagen® Multiplex PCR Kit, and following manufacturer conditions. Electrophoresis was performed on an ABI PRISMTM 310 Capillary Sequencer. Alleles sizing was achieved with GeneScan®3.1.2, with TAMRA® size standard for set1, and ROX® size standard for set2.
Total allele frequencies (Table 1) were estimated for the overall Portuguese population, based on the 110 typed samples, using the ARLEQUIN version 2.000 software (Schneider et al, 2000). Hardy-Weinberg equilibrium departures, as well as linkage equilibrium departures, were estimated using the same software. The level of structuring, in Portuguese wild boar population, was assessed using the software STRUCTURE 2.0 (Pritchard et al, 2000; Falush et al, 2003). There were no a priori assumptions about the number of sub-populations, if any. As so, during the simulation procedure, the number of sample clusters was made to vary between K=1 and K=10. For each K, were preformed 5 runs of 106 iterations each, after a “burnin” period of 50000 iterations.
The posterior probability (Table 2) was estimated for each K, as well as the assignment probabilities of each individual to each of the inferred K clusters. The numbers of individuals with assignment probabilities greater than some defined thresholds (95, 90 and 80%), for the cluster geographically closest to its capture location, were also estimated (Table 3).
Significant values of Hardy-Weinberg disequilibrium (HWD) for several markers, as well as linkage disequilibrium (LD) between independent (placed in different chromosomes) markers, might be considered as strongly suggesting structuring of a population (Hartl & Clark, 1997). All the six microsatellites used in this study are placed at different chromosomes, and both HWD and LD were detected with our sample set. The simulation procedure with STRUCTURE package also suggests structuring, with strong evidence for the existence of 3 different subgroups of individuals. In fact, the probability, P(K=3)1.00, against P(K)0.00 probabilities for all other considered K, strongly supports the 3 subpopulations model. A good correspondence was verified between the 3 inferred clusters and the geographic data, with individuals captured in closer locations clustering together. Several individuals showed similar assignment probabilities for more than one cluster, which can indicate an admixed origin or ancestry from more than one subpopulation.
Keywords: multiplex amplification, assignment probability, allele frequencies, Portugal, wild boar.
... The wolverine (Gulo gulo) is the largest terrestrial member of the mustelid family, occurring in naturally low densities across its circumpolar distribution in tundra, taiga, and boreal forest regions of North America and Eurasia (Kyle andStrobeck 2001, Golden et al. 2007a). Their low reproductive rate and large space requirements make wolverine populations vulnerable to increased mortality or loss of habitat. ...
... Royle et al. 2011). Because wolverine populations in Alaska show weak genetic differentiation (Kyle and Strobeck 2001), the animals using the WSA likely represent a high-density component of a larger metapopulation. Previous work in the WSA did not examine wolverine abundance (Whitman and Ballard 1984), making this the first such estimate for the area. ...
... Determining fine-scale population structure is especially difficult for wide-ranging species that inhabit remote areas where geographic boundaries are lacking or indistinct and events such as mating are difficult to observe. Such challenges were evident in studies of highly mobile carnivores with low densities and vast distributions (e.g., Cegelski, Waits, & Anderson, 2003;Kyle & Strobeck, 2001;Roy, Geffen, Smith, Ostrander, & Wayne, 1994;Sinclair et al., 2001). However, genetic approaches have the potential to provide insight into problems in conservation (Allendorf et al., 2010). ...
Defining subpopulations using genetics has traditionally used data from microsatellite markers to investigate population structure; however, single-nucleotide polymorphisms (SNPs) have emerged as a tool for detection of fine-scale structure. In Hudson Bay, Canada, three polar bear (Ursus maritimus) subpopulations (Foxe Basin (FB), Southern Hudson Bay (SH), and Western Hudson Bay (WH)) have been delineated based on mark–recapture studies, radiotelemetry and satellite telemetry, return of marked animals in the subsistence harvest, and population genetics using microsatellites. We used SNPs to detect fine-scale population structure in polar bears from the Hudson Bay region and compared our results to the current designations using 414 individuals genotyped at 2,603 SNPs. Analyses based on discriminant analysis of principal components (DAPC) and STRUCTURE support the presence of four genetic clusters: (i) Western—including individuals sampled in WH, SH (excluding Akimiski Island in James Bay), and southern FB (south of Southampton Island); (ii) Northern—individuals sampled in northern FB (Baffin Island) and Davis Strait (DS) (Labrador coast); (iii) Southeast—individuals from SH (Akimiski Island in James Bay); and (iv) Northeast—individuals from DS (Baffin Island). Population structure differed from microsatellite studies and current management designations demonstrating the value of using SNPs for fine-scale population delineation in polar bears.
... Interestingly, populations resulting from the two distinct processes may be adaptively and demographically very different. Considering the prevalence of remnant groups in carnivore populations around the world [19][20][21][22][23][24][25][26][27][28][29], the ongoing recovery of many populations [64], and the increasing probability of range shifts, contractions and expansions related to climate change, we expect that neutral and adaptive evolutionary changes caused by recolonization and assimilation will be increasingly common. ...
Current range expansions of large terrestrial carnivores are occurring following human-induced range contraction. Contractions are often incomplete, leaving small remnant groups in refugia throughout the former range. Little is known about the underlying ecological and evolutionary processes that influence how remnant groups are affected during range expansion. We used data from a spatially explicit, long-term genetic sampling effort of grizzly bears ( Ursus arctos ) in the Northern Continental Divide Ecosystem (NCDE), USA, to identify the demographic processes underlying spatial and temporal patterns of genetic diversity. We conducted parentage analysis to evaluate how reproductive success and dispersal contribute to spatio-temporal patterns of genetic diversity in remnant groups of grizzly bears existing in the southwestern (SW), southeastern (SE) and east-central (EC) regions of the NCDE. A few reproductively dominant individuals and local inbreeding caused low genetic diversity in peripheral region
... El exceso de heterocigotos puede ser explicado por varias causas, la primer causa está relacionada con las características del microsatélite ya que este se puede encontrar ligado a algún otro gen que esté siendo afectado por "heterosis" que es la selección positiva a favor de los heterocigotos ( (Cullingham et al., 2006;Siripunkaw et al., 2007) el carcayú Gulo gulo (Kyle y Strobeck, 2001), el visón americano Mustela vison (Fleming et al., 1999), el armiño Mustela erminea (Fleming et al., 1999), la garduña Martes foina (Basto et al., 2010), la cibelina Martes zibellina (Kashtanova et al., 2011), el tejón europeo Meles meles (Annavi et al., 2011) y el oso polar ...
ESCUELA NACIONAL DE CIENCIAS BIOLÓGICAS Aislamiento y caracterización de 24 microsatélites para el coatí de nariz blanca Nasua narica (Carnívora: Procyonidae) utilizando la técnica 454 de secuenciación PROYECTO DE INVESTIGACIÓN TESIS QUE PARA OBTENER EL TÍTULO DE: BIÓLOGO PRESENTA EDUARDO SÁNCHEZ GARIBAY MÉXICO, D.F. 2013
... Populations may be genetically structured at different spatial scales, ranging from local (Brouat et al. 2003;Coltman et al. 2003;Bouzat and Johnson 2004) to regional (Cegelski et al. 2003;Eriksson et al. 2004) to continental (Kyle and Strobeck 2001;Geffen et al. 2004;de Barro 2005). Processes that occur at these different scales affecting genetic structure include population dynamics such as colonization (Excoffier and Ray 2008), social organization (Lehman et al. 1992;Pope 1992;Girman et al. 1997;Støen et al. 2005), and/or dispersal limits (Wright 1943;Rousset 1997). ...
In the Canadian Rocky Mountains, the gray wolf (Canis lupus) has experienced range contractions and expansions, which can greatly affect pack stability as well as population structure. In addition, this area has a highly heterogeneous landscape that may form barriers to dispersal. To understand factors affecting pack structure and large-scale gene flow across the Rocky Mountains, we examined wolf genetic structure using 1,981 noninvasive and invasively collected samples. We sampled over 44 packs in Alberta and British Columbia and, from these, identified 540 individuals based on 12 microsatellites. Relatedness of individuals within packs was greater than between packs, and female relatedness was greater than males suggesting strong pack structure and female philopatry. Relatedness within packs was greater near major roads suggesting decreased dispersal from natal packs with proximity to roads. Across the study area, 2 significantly differentiated genetic clusters were identified, corresponding to a north/south split. Landcover distance was a significant correlate for 2 of 4 genetic distance measures, where packs in the north were in areas of dense coniferous forest, while packs in the south were primarily in open coniferous forest. These landcover differences suggest natal associations or could relate to prey distribution. Fine-scale investigation of pack dynamics across this continuous distribution, together with large-scale estimators of population structure, highlights different drivers of gene flow at the pack and population level.
... The finding of one panmictic breeding pool indicates that there are very high levels of gene flow across the continent. Despite their small size, cats have large continental-sized populations which have been demonstrated in other highly mobile vertebrates (Kyle and Strobeck 2001;Schwartz et al. 2002), including newly introduced invasive species, such as the camel in Australia (Spencer et al. 2012). More commonly, highly structured populations have been identified for several invasive species, including feral cats (Pontier et al. 2005;Hansen et al. 2007), rabbits (Fuller et al. 1997), feral pigs (Hampton et al. 2004;Cowled et al. 2008), rats (Ruscoe et al. 1998;Abdelkrim et al. 2005), and birds (Rollins et al. 2009). ...
The historical literature suggests that in Australia, the domestic cat (Felis catus) had a European origin [~200 years before present (ybp)], but it is unclear if cats arrived from across the Asian land bridge
contemporaneously with the dingo (4000 ybp), or perhaps immigrated ~40000 ybp in association with Aboriginal settlement from
Asia. The origin of cats in Australia is important because the continent has a complex and ancient faunal assemblage that
is dominated by endemic rodents and marsupials and lacks the large placental carnivores found on other large continents. Cats
are now ubiquitous across the entire Australian continent and have been implicit in the range contraction or extinction of
its small to medium sized (<3.5kg) mammals. We analyzed the population structure of 830 cats using 15 short tandem repeat
(STR) genomic markers. Their origin appears to come exclusively from European founders. Feral cats in continental Australia
exhibit high genetic diversity in comparison with the low diversity found in populations of feral cats living on islands.
The genetic structure is consistent with a rapid westerly expansion from eastern Australia and a limited expansion in coastal
Western Australia. Australian cats show modest if any population structure and a close genetic alignment with European feral
cats as compared to cats from Asia, the Christmas and Cocos (Keeling) Islands (Indian Ocean), and European wildcats (F. silvestris silvestris).
... The types of questions that can be addressed with both traditional population parameters and individual-based clustering methods include, for example, delineation of population boundaries and detection of cryptic population structure (e.g. Kyle & Strobeck, 2001) or estimation of dispersal rates and patterns (Berry et al., 2005). These questions are central to conservation and management of rare and endangered taxa (e.g. ...
In order to secure pollination services and improve conservation strategies, a better understanding of factors influencing population structure of pollinator species is vital. Here, we aimed to empirically evaluate various individual-and population-based statistical methods for characterization of genetic structure of the widespread dronefly, Eristalis tenax. Thirty-five European populations, comprising 888 individuals, were genotyped at five polymorphic allozyme loci. Three Bayesian genotypic clustering approaches (STRUCTURE, BAPS and Geneland), pairwise FST estimates, analyses of molecular variance (AMOVA), principle component analysis (PCA) and Mantel tests were applied in a comparative way in attempt to reveal the patterns of gene flow that occurs at various spatial scales in E. tenax. STRUCTURE analysis and PCA results provided no evidence of conspecific differentiation. In contrast, BAPS and Geneland clustering solutions did acknowledge low but significant proportion of among-populations genetic variation revealed by AMOVA. Similarly, pairwise FST estimates partially argue against genetic homogeneity across Europe. The lack of correlation between genetic distance and both latitude and longitude variation suggests that the flies disperse in multiple directions. Therefore, our results indicate that continued long-range dispersal tend to homogenize populations over time, resulting in little population structure in E. tenax across the European landmass. On the other hand, significant differentiations between geographically proximate populations indicate that dispersal potential may not be realized and that gene flow patterns in E. tenax might be geographically complex. Using information from our genetic approaches will be useful for identifying patterns of migration and population connectivity across continent, which is an important issue for conservation efforts. Since E. tenax is an important pollinator, our results contribute to understanding the potential extent to which this taxon can facilitate gene flow among plant populations across natural and semi-natural habitats, agroecosystems and urban environments. Dronefly-mediated gene flow in plants is likely to occur over large distances and plant–dronefly conservation will require large-scale action.
... Wolverines select crossings <100m in width, avoiding larger openings COSEWIC 2003a). High traffic roads can act as dispersal barriers (Kyle and Strobeck 2001). ...
... Lower genetic diversity in fragmented populations has been described in a wide range of taxonomic groups including rodents (Tallmon et al. 2002;Hirota et al. 2004), reptiles (Cunningham and Moritz 1998;Sumner et al. 2004), amphibians (Wahbe et al. 2005), marsupials (Banks et al. 2005;Lancaster et al. 2011), different carnivores such as ursids (Dixon et al. 2007), canids (Leigh et al. 2012), mustelids (Kyle and Strobeck 2001;Dallas et al. 2002), and several felid species such as jaguar (Panthera onca; Haag et al. 2010 ...
Landscape fragmentation is often a major cause of species extinction as it can affect a wide variety of ecological processes. The impact of fragmentation varies among species depending on many factors, including their life-history traits and dispersal abilities. Felids are one of the groups most threatened by fragmented landscapes because of their large home ranges, territorial behavior, and low population densities. Here, we model the impacts of habitat fragmentation on patterns of genetic diversity in the guigna (Leopardus guigna), a small felid that is closely associated with the heavily human-impacted temperate rainforests of southern South America. We assessed genetic variation in 1798 base pairs of mitochondrial DNA sequences, 15 microsatellite loci, and 2 sex chromosome genes and estimated genetic diversity, kinship, inbreeding, and dispersal in 38 individuals from landscapes with differing degrees of fragmentation on Chiloé Island in southern Chile. Increased fragmentation was associated with reduced genetic diversity, but not with increased kinship or inbreeding. However, in fragmented landscapes, there was a weaker negative correlation between pairwise kinship and geographic distance, suggesting increased dispersal distances. These results highlight the importance of biological corridors to maximize connectivity in fragmented landscapes and contribute to our understanding of the broader genetic consequences of habitat fragmentation, especially for forest-specialist carnivores.
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... Populations may be genetically structured at different spatial scales, ranging from local (Brouat et al. 2003;Coltman et al. 2003;Bouzat and Johnson 2004) to regional (Cegelski et al. 2003;Eriksson et al. 2004) to continental (Kyle and Strobeck 2001;Geffen et al. 2004;de Barro 2005). Processes that occur at these different scales affecting genetic structure include population dynamics such as colonization (Excoffier and Ray 2008), social organization (Lehman et al. 1992;Pope 1992;Girman et al. 1997;Støen et al. 2005), and/or dispersal limits (Wright 1943;Rousset 1997). ...
Winner of the 1984 Wildlife Publications Award from the Wildlife Society, the first edition of Wild Mammals of North America (published in 1982) offered zoologists, naturalists, wildlife specialists, and students detailed information about the biology, conservation status, and management of 57 mammalian species and species groups, with contributions from 100 of the leading authorities. Now thoroughly revised to reflect new biological research and approaches to wildlife conservation and management, the second edition of this "essential volume" ( Wildlife Society Bulletin) continues to provide the most current and comprehensive data on the distribution, physiology, ecology, behavior, commercial value, and viability of nongame species including bats, woodrats, prairie dogs, and armadillo, the whales, seals, and sireians, as well as carnivores, furbearers, and big game species.
... This is due to the fact that populations with a large census size N mostly also have a large effective population size N e [Frankham, 1995b], a measure indicating the number of individuals in a theoretical idealized population possessing the same diversity characteristics as the study population [Wright, 1931] It has further been shown that genetic diversity is often lower in fragmented versus continuous landscapes, because fragmented populations experience increased genetic drift and restricted gene flow [e.g. Caizergues et al., 2003;Kyle & Strobeck, 2001]. Interestingly, some studies investigated different species occupying the same fragmented landscapes and found variation in their response to fragmentation. ...
Gorillas, like all non-human great apes, are endangered. Understanding the distribution of genetic diversity across their range is important because low diversity may arise in small populations through increased inbreeding, and, by reducing reproductive fitness, may lead to decreased chances of persistence of a given population. Previous studies found higher genetic diversity in the western (Gorilla gorilla) than in the eastern gorillas (Gorilla beringei), but rarely employed individuals of known geographic origin to investigate the distribution of diversity across multiple populations. The present study fills that gap by analyzing 1,161 individuals from nine sites across all four currently recognized Gorilla subspecies. Genetic diversity at each site was estimated using published data from seven highly-variable microsatellite loci. We found that the small and fragmented populations of Cross River gorillas, eastern lowland gorillas and mountain gorillas were less diverse than any of the five analyzed western lowland gorilla populations. The higher levels of genetic variation within the western lowland gorillas might be best explained by the facts that they (i) exhibit larger present and past effective population sizes than the other subspecies and (ii) maintain higher rates of gene flow through the existence of largely continuous habitat within their range. With regard to conservation, the high genetic diversity within western lowland gorillas is encouraging and retention of dispersal corridors between already protected areas is essential. Am. J. Primatol. © 2015 Wiley Periodicals, Inc.
© 2015 Wiley Periodicals, Inc.
... Landscape configuration may also influence dispersal, which in turn affects the degree of genetic structuring. Species with high levels of gene flow attributed to vagility, continuous distribution of habitat, or habitat generalization generally have weak genetic structure (Forbes and Hogg 1999;Kyle and Strobeck 2001;Schwartz et al. 2002). Mountainous landscapes may increase genetic structure in natural populations by limiting seasonal movements and dispersal distances (Lomolino and Davis 1997). ...
Identifying patterns of fine-scale genetic structure in natural populations can advance understanding of critical ecological processes such as dispersal and gene flow across heterogeneous landscapes. Alpine ungulates generally exhibit high levels of genetic structure due to female philopatry and patchy configuration of mountain habitats. We assessed the spatial scale of genetic structure and the amount of gene flow in 301 Dall’s sheep (Ovis dalli dalli) at the landscape level using 15 nuclear microsatellites and 473 base pairs of the mitochondrial (mtDNA) control region. Dall’s sheep exhibited significant genetic structure within contiguous mountain ranges, but mtDNA structure occurred at a broader geographic scale than nuclear DNA within the study area, and mtDNA structure for other North American mountain sheep populations. No evidence of male-mediated gene flow or greater philopatry of females was observed; there was little difference between markers with different modes of inheritance (pairwise nuclear DNA F
ST = 0.004–0.325; mtDNA F
ST = 0.009–0.544), and males were no more likely than females to be recent immigrants. Historical patterns based on mtDNA indicate separate northern and southern lineages and a pattern of expansion following regional glacial retreat. Boundaries of genetic clusters aligned geographically with prominent mountain ranges, icefields, and major river valleys based on Bayesian and hierarchical modeling of microsatellite and mtDNA data. Our results suggest that fine-scale genetic structure in Dall’s sheep is influenced by limited dispersal, and structure may be weaker in populations occurring near ancestral levels of density and distribution in continuous habitats compared to other alpine ungulates that have experienced declines and marked habitat fragmentation.
... Page 1996). Relationships between wolverine sampling locations (i.e., populations) in the Rocky Mountains, Canada, and Alaska have been examined elsewhere (Kyle and Strobeck 2001, 2002; Cegelski et al 2003). To further compare California wolverines to other North American populations, we grouped samples into 4 geographic areas: California, Alaska, the greater Montana, USA, area (which included samples from MT and the greater Yellowstone ecosystem), and central Idaho and used program GENEPOP (Raymond and Rousset 1995) to estimate F st and R st (indices of population subdivision). ...
Delineating a species' geographic range using the spatial distribution of museum specimens or even contemporary detection-non-detection data can be difficult. This is particularly true at the periphery of a species range where species' distributions are often disjunct. Wolverines (Gulo gulo) are wide-ranging mammals with discontinuous and potentially isolated populations at the periphery of their range. One potentially disjunct population occurred in the Sierra Nevada Mountains, California, USA, and appears to have been extirpated by the 1930s. Many early 20th century naturalists believed that this population was connected to other populations occurring in the Cascade Range of northern California, Oregon, and Washington, USA, but a recent analysis of historical records suggests that California wolverines were isolated from other populations in North America. We used DNA extracted from museum specimens to examine whether California wolverines were isolated. Both nuclear and mitochondrial DNA data indicate that California wolverines were genetically distinct from extant populations, suggesting long-term isolation. We identified 2 new control region (mitochondrial DNA) haplotypes located only within California. We used these data and referenced sequences from the Rocky Mountains, USA, to make inferences regarding potential wolverine translocations into California. In addition, we used these genetic data to make inferences about wolverine conservation throughout western North America.
У навчальному посібнику детально розглянуто представників чоти-рьох родин хижаків, зокрема ведмедевих, псових (вовчих), котових (котя-чих) і мустелових (куницевих). Подано загальні відомості про тварин, ареа-ли їх поширення, спосіб життя, розмноження, харчування. Висвітлено про-блеми збереження і приналежність до видових категорій згідно з Червоним списком Міжнародного союзу охорони природи.
Для студентів і викладачів географічних факультетів вищих закладів освіти, майбутніх фахівців у галузі географії і природничих наук, усіх, хто цікавиться життям тварин.
La variabilidad genética es un factor importante para la supervivencia de los individuos ya que permite a los individuos adaptarse a los cambios ambientales. A pesar de que al Nasua narica se le considera el único carnívoro verdaderamente sociable que habita en los bosques neotropicales, se sospecha que las poblaciones que habitan en Norteamérica se han aislado genéticamente de forma gradual, debido principalmente a la fragmentación y pérdida de hábitat.
Se analizaron la variabilidad y estructura genética del N. narica en cinco poblaciones de México (Parque Museo de La Venta, Parque Nacional El Tepozteco, Puerto Morelos, Punta Raza y Reserva de la Biosfera de Chamela-Cuixmala) mediante el uso de marcadores moleculares, 12 microsatélites específicos y un fragmento del gen de citocromo b. Los resultados mostraron niveles de moderados a altos en los indicadores de variabilidad genética para ambos marcadores genéticos. La heterocigosidad esperada (HE) fue de 0.664, mientras que la heterocigosidad observada (HO) fue de 0.774. La mayoría de los microsatélites se encontraron en equilibrio de Hardy-Weinberg. Todos los loci fueron polimórficos en las cinco poblaciones y el promedio de alelos por locus fue de 5.033 ± 1.794 (DE). La diversidad haplotípica (h) para las poblaciones en conjunto fue 0.968 ± 0.008 (DE) y la diversidad nucleotídica (π) de 0.007 ± 0.001 (DE).
Se registraron 22 haplotipos distintos, la mayoría fueron específicos de una de las áreas muestreadas, sólo tres se compartieron entre las distintas poblaciones. Se encontraron diferencias significativas entre las poblaciones de la Costa del Pacífico (Punta Raza y Reserva de la Biosfera Chamela-Cuixmala), las del centro (Parque Nacional El Tepozteco) y sureste del país (Parque Museo La Venta y Puerto Morelos), corroborando que el aislamiento genético tiene un efecto significativo en ésta especie resultando en una estructura genética compuesta por cinco diferentes subpoblaciones.
The wolverine is considered Data Deficient in Alberta. Alberta uses criteria developed by the International Union for Conservation of Nature (IUCN) when assessing species’ status. IUCN status designations are determined using a variety of criteria including a declining population size, extent of (and changes to) geographic range (e.g., extent of occurrence, or area of occupancy), a determination that population size is small and/or restricted, or a quantitative analysis on the probability of extinction (IUCN 2012). Alberta’s designation of Data Deficient is used when the available data are inadequate to determine the degree of threat faced by the species.
Several wolverine studies have occurred within Alberta since the provincial status assessment in 2000, and much more information is now available that will be useful for an updated status assessment, including abundance estimates for some regions of the province, areas of occupancy and occurrence, habitat ecology, and response to anthropogenic change. However, the data on population size within the province remains limited. Some extrapolation techniques might allow for coarse estimates at the provincial level, but there are limitations to these options. In particular, there are currently no robust population estimates for the Boreal Forest Natural Region even though this makes up the vast majority of the wolverine distribution in Alberta.
We estimated wolverine density for the Birch Mountains area using data originally collected for an occupancy study from 2016–2017. The study area was 1,976 km2 with an estimated density within the range of 0.66–3.00 per 1,000 km2 (95% CI). This estimate should be interpreted cautiously because of low precision and the failure to meet spatially explicit capture-recapture model assumptions regarding trap-specific behavioural response. A density estimate in the Rainbow Lake area of Alberta is currently underway; however, the study area was again relatively small and may not be representative for Alberta’s Boreal Forest Natural Region as a whole. Wolverine density estimates from studies in various locations in the Rocky Mountains and Foothills natural regions between 2004 and 2020 range from 1.3/1,000 km2 to 6.8/1,000 km2; however, differences in field and analysis methods make comparisons across studies difficult and should be interpreted cautiously.
In addition, there are limited available data to provide an estimate of population trend over time. Harvest records can provide an index of harvest and changes in the distribution of harvest, though these records are largely influenced by trapper effort, which has not been accounted for with wolverine harvest to date. In summary, data gaps that continue to exist include a current abundance estimate for the northern portion of the Rocky Mountains and Foothills, a reliable abundance estimate to represent the Boreal Forest Natural Region, and information to account for population trend across the province.
Suggested Citation:
Alberta Conservation Association. 2020. State of Knowledge for Alberta’s Wolverine Population 2020: Literature Review, Density Estimate, and Gap Analysis. Data Report, produced for the Alberta Conservation Association, Sherwood Park, Alberta, Canada. 41 pp + App. https://doi.org/10.13140/RG.2.2.28154.57284
Wolverines (Gulo gulo) occupy most of the globe's Arctic tundra. Given the rapidly warming climate and expanding human activity in this biome, understanding wolverine ecology, and therefore the species' vulnerability to such changes, is increasingly important for developing research priorities and effective management strategies. Here, we review and synthesize knowledge of wolverines in the Arctic using both Western science sources and available Indigenous Knowledge (IK) to improve our understanding of wolverine ecology in the Arctic and better predict the species' susceptibility to change. To accomplish this, we update the pan-Arctic distribution map of wolverines to account for recent observations and then discuss resulting inference and uncertainties. We use these patterns to contextualize and discuss potential underlying drivers of distribution and population dynamics, drawing upon knowledge of food habits, habitat associations, and harvest, as well as studies of wolverine ecology elsewhere. We then identify four broad areas to prioritize conservation and research efforts: (1) Monitoring trends in population abundance, demographics, and distribution and the drivers thereof, (2) Evaluating and predicting wolverines' responses to ongoing climate change, particularly the consequences of reduced snow and sea ice, and shifts in prey availability, (3) Understanding wolverines' response to human development, including the possible impact of wintertime over-snow travel and seismic testing to reproductive denning, as well as vulnerability to hunting and trapping associated with increased human access, and (4) Ensuring that current and future harvest are sustainable.
Supplementary information:
The online version contains supplementary material available at 10.1007/s00300-022-03079-4.
Maintaining connectivity between high-elevation public lands is important for wolverines and other species of conservation concern. This work represents the first effort to prioritize wolverine connectivity under future climate conditions using a systematic conservation planning framework. We optimized 10, 15, 20, and 50% of habitat features for wolverines using integer linear programming. We identified 369 privately owned areas in the 10% solution, 572 in the 15% solution, 822 in the 20% solution, and 3,996 in the 50% solution where voluntary landowner easements would improve the long-term landscape functionality for wolverine connectivity. The median estimated easements ranged from $8,762 to $12,220 across the four solutions (total costs $14,874,371 to $196,346,714). Overall, this effort demonstrates the utility of optimization problems for conserving connectivity, provides a proactive tool to engage potential collaborators, identifies easements that will likely protect various subalpine species, and offers a framework for the conservation of additional species.
The implementation of corridors has been suggested as a means of mitigating the negative effects of fragmentation by restoring or maintaining connectivity between populations. However, the role of corridors in facilitating the movement of large mammals has rarely been evaluated objectively. In this study, we used non-invasive techniques (genetic analysis of feces), microsatellite analysis and the Bayesian method to evaluate the effectiveness of the Serra do Mar as a corridor for large mammals in the Atlantic Forest. Two locations were sampled in the Serra do Mar - Intervales State Park and the Caraguatatuba Nucleus - and were separated by a distance of 300 km. The lowland tapir (Tapirus terrestris, Linnaeus 1758) is one of the largest surviving members of neotropical megafauna. The tapir is found in northern and central lowland regions of South America, encompassing Argentina, Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, Paraguay, Peru, Suriname and Venezuela. This species, the largest mammal native of Brazil, is an ideal model to test the effectiveness of the Serra do Mar as a corridor for large mammals because it has a large displacements, has the ability to cross the matrix in fragmented landscapes and is hunted for its meat. At Intervales State Park, 55 fecal samples were collected along an altitudinal gradient of 302 to 976 meters, while 76 fecal samples were collected along an altitudinal gradient of 530 to 865 meters at the Caraguatatuba Core (Serra do Mar State Park). The sampling effort consisted of 258.9 km and 351.6 km traversed at Intervales State Park and Caraguatatuba, respectively. Similarly, 16 and 23 individuals were identified with an amplification success of 31% and 33%, respectively. We estimated the population density at Intervales State Park between 0,20-0,57 individuals per km2.
Climate change can have particularly severe consequences for high-elevation species that are well-adapted to long-lasting snow conditions within their habitats. One such species is the wolverine, Gulo gulo, with several studies showing a strong, year-round association of the species with the area defined by persistent spring snow cover. This bioclimatic niche also predicts successful dispersal paths for wolverines in the contiguous United States, where the species shows low levels of genetic exchange and low effective population size. Here, we assess the influence of additional climatic, vegetative, topographic, and anthropogenic, variables on wolverine genetic structure in this region using a multivariate, multiscale, landscape genetic approach. This approach allows us to detect landscape-genetic relationships both due to typical, small-scale genetic exchange within habitat, as well as exceptional, long-distance dispersal among habitats. Results suggest that a combination of snow depth, terrain ruggedness, and housing density, best predict gene flow in wolverines, and that the relative importance of variables is scale-dependent. Environmental variables (i.e., isolation-by-resistance, IBR) were responsible for 79% of the explained variation at small scales (i.e., up to ~230 km), and 65% at broad scales (i.e., beyond ~420 km). In contrast, a null model based on only space (i.e., isolation-by-distance, IBD) accounted only for 17% and 11% of the variation at small and broad scales, respectively. Snow depth was the most important variable for predicting genetic structures overall, and at small scales, where it contributed 43% to the variance explained. At broad spatial scales, housing density and terrain ruggedness were most important with contributions to explained variation of 55% and 25%, respectively. While the small-scale analysis most likely captures gene flow within typical wolverine habitat complexes, the broad-scale analysis reflects long-distance dispersal across areas not typically inhabited by wolverines. These findings help to refine our understanding of the processes shaping wolverine genetic structure, which is important for maintaining and improving functional connectivity among remaining wolverine populations.
Wolverines are highly vagile carnivores, with long-distance dispersal documented for males and females. Consequently, the species was thought to represent 1 large, panmictic unit in North America. In this study, we examined the connectivity of populations on the edge of their historical distribution to the larger, continuous, northern distribution of wolverines. Twenty-two regions were sampled, and 671 individuals were genotyped at 12 microsatellite loci. Our results confirmed that high levels of gene flow do occur among all the northern wolverine populations sampled. We also observed progressively increasing genetic structure at the periphery of their southern and eastern distributions, suggesting that these populations may have been partially fragmented from what was once a panmictic unit. Peripheral populations may be more susceptible to extirpation and, therefore, may be the most appropriate targets for concerted conservation efforts to prevent the elimination of wolverines from yet more of their historical range.
After decades, even centuries of persecution, large carnivore populations are widely recovering in Europe. Considering the recent recovery of the wolverine (Gulo gulo) in Finland, our aim was to evaluate genetic variation using 14 microsatellites and mtDNA control region (579 bp) in order (1) to determine whether the species is represented by a single genetic population within Finland, (2) to quantify the genetic diversity, and (3) to estimate the effective population size. We found two major genetic clusters divided between eastern and northern Finland based on microsatellites (FST = 0.100) but also a significant pattern of isolation by distance. Wolverines in western Finland had a genetic signature similar to the northern cluster, which can be explained by former translocations of wolverines from northern to western Finland. For both main clusters, most estimates of the effective population size Ne were below 50. Nevertheless, the genetic diversity was higher in the eastern cluster (HE = 0.57, AR = 4.0, AP = 0.3) than in the northern cluster (HE = 0.49, AR = 3.7, AP = 0.1). Migration between the clusters was low. Two mtDNA haplotypes were found: one common and identical to Scandinavian wolverines; the other rare and not previously detected. The rare haplotype was more prominent in the eastern genetic cluster. Combining all available data, we infer that the genetic population structure within Finland is shaped by a recent bottleneck, isolation by distance, human-aided translocations and postglacial recolonization routes.
The wolverine (Gulo gulo), a carnivore species of ‘Special Concern’ for its western population and ‘Endangered’ for its eastern population, is of special management concern in Canada. Hence understanding human-wolverine relationships and human perceptions toward this carnivore species has become important. Moreover, wolverines are harvested for fur in northern Canada, thus hunters and trappers who live in the vicinity with this species are key stakeholders. Using semi-structured interviews and questionnaires we analysed human-wolverine interactions and perceptions among Dene and Métis hunters and trappers in the Canadian Northwest Territories. We found that hunters and trappers had comprehensive knowledge about wolverine ecology and behavior. Values associated with this species ranged from respect for their tenacious character and strength, to describing the wolverine as a trickster. Stories emphasizing the wolverines’ mischievous nature were also common. Dene and Métis hunters and trappers acknowledge the importance of the wolverine in the socio-ecological system and have observed the cumulative impacts that climate and human-induced landscape change have had on wolverine habitat and population dynamics. Listening to hunters and trappers is one path towards more insightful management options in situations involving conflicts with wolverines.
Genetic variability is an important survival factor that allows individuals to adapt to environmental changes. Although the white-nosed coati is considered the only truly social carnivore that lives in neotropical forests, is suspected that populations in North America have been isolated genetically gradually, mainly due to habitat loss and fragmentation. Variability and genetic structure of 𝘕. 𝘯𝘢𝘳𝘪𝘤𝘢 were analyzed in five populations of Mexico (Parque Museo de La Venta, Parque Nacional El Tepozteco, Puerto Morelos, Punta Raza and Reserva de la Biosfera de Chamela-Cuixmala) using two molecular markers: 12 specific microsatellites and a fragment of the gene cytochrome-b. The results showed from moderate to high levels indicators of genetic variability for both genetic markers. The expected heterozygosity (H🇪 ) was 0.774, whereas the observed heterozygosity (H🇴 ) was 0.664. Most microsatellites were in Hardy- Weinberg equilibrium. All loci were polymorphic in the five populations, and the average number of alleles per locus was 5.033 ± 1.545 (SD). The haplotype diversity (𝘩) for all populations was 0.968 ± 0.008 (SD) and nucleotide diversity (π) of 0.007 ± 0.001 (SD). Twenty-two different haplotypes were recorded, most of them were specific to one of the sampled areas and only three of them were shared between the different populations. Significant differences between the populations of the Pacific Coast (Punta Raza and Reserva de la Biosfera de Chamela-Cuixmala), the center (Parque Nacional El Tepozteco) and southeast (Parque Museo de La Venta and Puerto Morelos) were found, confirming that genetic isolation has a significant effect on this species resulting in a genetic structure integrated of five different subpopulations.
Reintroduction programs have been pivotal in augmenting populations of fishers (Pekania pennanti (Erxleben, 1777)) and re-establishing them to their former range in North America. The majority of reintroduction efforts in fishers have been considered demographically successful, but reintroductions can alter genetic population structure and success has rarely been evaluated in fishers from a genetic standpoint. We used microsatellite data (n = 169) to examine genetic population structure of fishers in the Great Lakes region and comment on the success of past reintroductions at two different spatial scales. We found significant genetic population structure among source and reintroduced populations within the Great Lakes region and largescale genetic structure between fisher populations located in two geographically distant regions (Great Lakes and Northeast) in the eastern United States. Reintroductions associated with the Great Lakes produced results that were largely consistent with other studies of fisher reintroductions in the Northeast. However, our data are the first to support a measurable impact on genetic population structure in Pekania pennanti pennanti (Erxleben, 1777) from a reintroduction using geographically distant source and reintroduced populations. When feasible, we strongly recommend that reintroduction programs include an investigation of the underlying genetic structure to better define intended goals and supplement measures of demographic success.
Genetic variability and population structure was investigated in 83 European polecats Mustela putorius by means of six microsatellite markers. The samples came from two areas in Denmark, Ostjylland and Thy, which are separated by the Limfjord. The genetic diversity (H-e = 0.583) found in the total sample was similar to those found in other mustelid species and carnivores in general. A heterozygote deficiency, probably due to a Wahlund effect, suggested a further substructuring of the Danish sample. Population genetic substructuring was investigated in three different ways: by means of the program STRUCTURE, Wright's F-statistics and by an assignment test. All the tests indicate a subdivision of the sample into two distinct groups; which is concordant with the two sampling locations, with an average genetic divergence of F-ST = 0. 126 and R-ST = 0.1692. The higher genetic diversity found in the Thy population (H-e = 0.578), as compared to the Ostjylland population (H-e = 0.420), could be explained by assuming two ancient waves of colonisation of the Danish peninsula. Tests for recent bottlenecks were conducted, and the results suggest no evidence of neither population decline nor expansion. Our study is the first one in which microsatellite markers are used on polecat samples, and one locus (mv54) was found to be diagnostic in distinguishing between American mink Mustela vison and European polecat.
Full results of project are here: http://www.defenders.org/sites/default/files/publications/no_refuge_from_warming_climate_change_vulnerability_of_the_mammals_of_the_arctic_national_wildlife_refuge.pdf
To assess the genetic variation and population structure of the sable Martes zibellina on eastern Hokkaido, Japan, we analyzed genotypes of 12 microsatellite loci on 48 individuals. Genotypes for all individuals examined were found to be different from each other. Mean observed and expected heterozygosites and allelic richness were calculated to be 0.52 (0.02–0.80), 0.58 (0.02– 0.79) and 5.49, respectively. The genetic diversity of the eastern Hokkaido population was similar to those of farm-bred sables in Russia and other mustelids. STRUCTURE analysis showed that the sables of eastern Hokkaido were grouped into two genetic clusters. Eighty-nine percent (24/27) of individuals assigned to cluster 1 were distributed around Shiretoko Peninsula, whereas 81% (17/21) assigned to cluster 2 were distributed in the inner side of Hokkaido (Tokachi District). The two subpopulations could have been genetically differentiated due to geographic barriers such as higher mountains, lakes, rivers and solfatara areas, although the geographic isolation did not seem to be complete.
We have examined patterns of variation of several kinds of molecular markers (isozymes, RFLPs of ribosomal DNA and anonymous low-copy number DNA, RAPDs and microsatellites) and an adaptive trait [date of bud set in Scots pine (Pinus sylvestris L.)]. The study included Finnish Scots pine populations (from latitude 60°N to 70°N) which experience a steep climatic gradient. Common garden experiments show that these populations are adapted to the location of their origin and genetically differentiated in adaptive quantitative traits, e.g. the date of bud set in first-year seedlings. In the northernmost population, bud set took place about 21 days earlier than in the southernmost population. Of the total variation in bud set, 36.4% was found among the populations. All molecular markers showed high levels of within-population variation, while differentiation among populations was low. Among all the studied markers, microsatellites were the most variable (He=0.77). Differences between populations were small, GST was less than 0.02. Our study suggests that molecular markers may be poor predictors of the population differentiation of quantitative traits in Scots pine, as exemplified here by bud-set date.
Because of anthropogenic factors in the early 1900s that caused populations to decline dramatically, wolverines (Gulo gulo) currently are designated as endangered in eastern Canada and classified as vulnerable throughout the Holarctic Region by the International Union for Conservation of Nature and Natural Resources. Although numerous examples exist that illustrate the utility of genetic data for development of conservation plans, no study has investigated the genetic structure of natural populations of wolverines. We assessed allozymic and mitochondrial DNA (mtDNA) variability of wolverines within and among 5 sites from the Northwest Territories, Canada. Five of 46 presumptive allozyme loci were polymorphic. Estimates of heterozygosity (2.6%) and polymorphism (11.6%) were lower than values reported for most mammals but were within the range reported for Carnivora. To evaluate levels of variation in mtDNA, we sequenced the left domain of the control region. Six variable nucleotide sites were observed, resulting in 9 haplotypes of mtDNA. Within-site diversity of haplotypes (h) was high, but within-site diversity of nucleotides (Π) was low, indicating little sequence divergence among the 9 haplotypes. Sequence data for mtDNA revealed considerably more genetic partitioning among sites (ΦST = 0.536) than did allozyme data (FST = 0.076). Based on fixation indices, gene flow estimates (Nm) were moderate for nuclear markers but low for mtDNA loci. These findings suggest that, although wolverines maintain large home ranges, they exhibit fidelity to discrete areas, gene flow is predominantly male-mediated, and most sites in the Northwest Territories are genetically independent and thus represent populations. Therefore, any conservation plan for wolverines in the Northwest Territories must consider preservation of populations if genetic diversity of this taxon is to be maintained.
Formulae are given for estimators for the parameters F, θ, f (FIT, FST, FIS) of population structure. As with all such estimators, ratios are used so that their properties are not known exactly, but they have been found to perform satisfactorily in simulations. Unlike the estimators in general use, the formulae do not make assumptions concerning numbers of populations, sample sizes, or heterozygote frequencies. As such, they are suited to small data sets and will aid the comparisons of results of different investigators. A simple weighting procedure is suggested for combining information over alleles and loci, and sample variances may be estimated by a jackknife procedure.
Note that an updated reference for Genepop is Rousset (2008) genepop’007: a complete re-implementation of the genepop software for Windows and Linux (DOI: 10.1111/j.1471-8286.2007.01931.x)
The Hardy-Weinberg law plays an important role in the field of population genetics and often serves as a basis for genetic inference. Because of its importance, much attention has been devoted to tests of Hardy-Weinberg proportions (HWP) over the decades. It has long been recognized that large-sample goodness-of-fit tests can sometimes lead to spurious results when the sample size and/or some genotypic frequencies are small. Although a complete enumeration algorithm for the exact test has been proposed, it is not of practical use for loci with more than a few alleles due to the amount of computation required. We propose two algorithms to estimate the significance level for a test of HWP. The algorithms are easily applicable to loci with multiple alleles. Both are remarkably simple and computationally fast. Relative efficiency and merits of the two algorithms are compared. Guidelines regarding their usage are given. Numerical examples are given to illustrate the practicality of the algorithms.
Attempts to study the genetic population structure of large mammals are often hampered by the low levels of genetic variation observed in these species. Polar bears have particularly low levels of genetic variation with the result that their genetic population structure has been intractable. We describe the use of eight hypervariable microsatellite loci to study the genetic relationships between four Canadian polar bear populations: the northern Beaufort Sea, southern Beaufort Sea, western Hudson Bay, and Davis Strait-Labrador Sea. These markers detected considerable genetic variation, with average heterozygosity near 60% within each population. Interpopulation differences in allele frequency distribution were significant between all pairs of populations, including two adjacent populations in the Beaufort Sea. Measures of genetic distance reflect the geographic distribution of populations, but also suggest patterns of gene flow which are not obvious from geography and may reflect movement patterns of these animals. Distribution of variation is sufficiently different between the Beaufort Sea populations and the two more eastern ones that the region of origin for a given sample can be predicted based on its expected genotype frequency using an assignment test. These data indicate that gene flow between local populations is restricted despite the long-distance seasonal movements undertaken by polar bears.
A large microsatellite data set from three species of bear (Ursidae) was used to empirically test the performance of six genetic distance measures in resolving relationships at a variety of scales ranging from adjacent areas in a continuous distribution to species that diverged several million years ago. At the finest scale, while some distance measures performed extremely well, statistics developed specifically to accommodate the mutational processes of microsatellites performed relatively poorly, presumably because of the relatively higher variance of these statistics. At the other extreme, no statistic was able to resolve the close sister relationship of polar bears and brown bears from more distantly related pairs of species. This failure is most likely due to constraints on allele distributions at microsatellite loci. At intermediate scales, both within continuous distributions and in comparisons to insular populations of late Pleistocene origin, it was not possible to define the point where linearity was lost for each of the statistics, except that it is clearly lost after relatively short periods of independent evolution. All of the statistics were affected by the amount of genetic diversity within the populations being compared, significantly complicating the interpretation of genetic distance data.
We studied genetic structure in polar bear (Ursus maritimus) populations by typing a sample of 473 individuals spanning the species distribution at 16 highly variable microsatellite loci. No genetic discontinuities were found that would be consistent with evolutionarily significant periods of isolation between groups. Direct comparison of movement data and genetic data from the Canadian Arctic revealed a highly significant correlation. Genetic data generally supported existing population (management unit) designations, although there were two cases where genetic data failed to differentiate between pairs of populations previously resolved by movement data. A sharp contrast was found between the minimal genetic structure observed among populations surrounding the polar basin and the presence of several marked genetic discontinuities in the Canadian Arctic. The discontinuities in the Canadian Arctic caused the appearance of four genetic clusters of polar bear populations. These clusters vary in total estimated population size from 100 to over 10 000, and the smallest may merit a relatively conservative management strategy in consideration of its apparent isolation. We suggest that the observed pattern of genetic discontinuities has developed in response to differences in the seasonal distribution and pattern of sea ice habitat and the effects of these differences on the distribution and abundance of seals.
At least 3 areas in the state (Selkirk Mountains, Lochsa and Kelly Creek drainages, Sawtooth and Smoky Mountains) appear to contain Gulo gulo populations. These areas are remote, mountainous habitat with little human disturbance. The present-day distribution of the wolverine in Idaho is probably in the mountainous portions of the state from the South Fork of the Boise River north to the Canadian border. -from Author
A. method for estimating the average level of gene flow in a subdivided population, as measured by the average number of migrants exchanged between local populations, Nm, is presented. The results from a computer simulation model show that the logarithm of Nm is approximately linearly related to the logarithm of the average frequency of private alleles, p̄(1), in a sample of alleles from the population. It is shown that this result is relatively insensitive to changes in parameters of the model other than Nm and the number of individuals sampled per population. The dependence of the value of p̄(1) on the numbers of individuals sampled provides a rough way to correct for differences in sample size. This method was applied to data from 16 species, showing that estimated values of Nm range from much greater than 1 to less than 0.1. These results confirm the qualitative analysis of Slatkin (1981). This method was also applied to subsamples from a population to show how to measure the extent of isolation of local populations.
The distribution and connectivity of wolverine (Gulo gulo) populations in the northwestern United States is largely unknown. We investigated the potential distribution of wolverine in the Northwest and the importance of the Seven Devils Mountains for connecting populations in Idaho and Oregon; Mapping documented sightings suggested 3 relatively distinct subpopulation the 1) Cascade Mountains of Washington, 2) Cascade Mountains of Oregon, and 3) Rocky Mountains of Idaho. Sightings across mountainous habitats of Oregon also suggest that the Seven Devils Mountains may provide the only suitable habitat linking wolverine subpopulations in Idaho and Oregon. We confirmed the first observation of a wolverine in the Seven Devils Mountains during a helicopter survey in March 1998. The lack of previous sightings suggested limited dispersal between Oregon and Idaho. Low dispersal may impact the regional viability of wolverine by lowering the likelihood that suitable habitat patches are inhabited over time. Maintaining and enhancing the integrity of movement corridors between the Seven Devils Mountains and other contiguous mountain habitats in Idaho and Oregon may be essential for ensuring regional wolverine persistence.
To determine if threatened brown bear (Ursus arctos) populations of Montana and Wyoming have lower levels of genetic variation than other North American populations, we examined mitochondrial DNA (mtDNA) and nuclear microsatellite DNA diversity in 220 brown bears from 5 areas: Kodiak Island, Alaska; Kluane National Park, Canada; Eastern Slope of the Rockies (East Slope), Canada; Yellowstone ecosystem (YE), Wyoming and Montana; and Northern Continental Divide Ecosystem (NCDE), Montana and British Columbia. Nei's genetic diversity (h) was estimated by analyzing 296 base pairs of control region sequence data from mtDNA and by nuclear microsatellite analysis of 8 independent loci. Genetic diversity was lowest in the Kodiak Island sample. The YE and East Slope samples had intermediate levels of mtDNA diversity and microsatellite diversity. Kluane and NCDE samples had high levels of mtDNA diversity and microsatellite diversity. Genetic diversity in the YE and NCDE samples was lower than in the Kluane sample; however, these differences were statistically signficant (P < 0.05) for only 1 microsatellite locus in the YE sample. In contrast, the Kodiak Island sample had significantly less diversity (P < 0.05) than the Kluane sample at the mtDNA locus and 6 microsatellite loci. Because genetic diversity has been suggested as critical for the evolutionary fitness of wild populations, the management implications of these results are examined and discussed.
A method for estimating the average level of gene flow in a subdivided population, as measured by the average number of migrants exchanged between local populations, Nm, is presented. The results from a computer simulation model show that the logarithm of Nm is approximately linearly related to the logarithm of the average frequency of private alleles, p̄(1), in a sample of alleles from the population. It is shown that this result is relatively insensitive to changes in parameters of the model other than Nm and the number of individuals sampled per population. The dependence of the value of p̄(1) on the numbers of individuals sampled provides a rough way to correct for differences in sample size. This method was applied to data from 16 species, showing that estimated values of Nm range from much greater than 1 to less than 0.1. These results confirm the qualitative analysis of Slatkin (1981). This method was also applied to subsamples from a population to show how to measure the extent of isolation of local populations.
Elucidating the population genetic structure of a species gives us insight into the levels of gene flow between geographic regions. Such data may have important implications for those trying to manage a heavily harvested wildlife species by determining the genetic connectivity of adjacent populations. In this study, the population structure of 12 North American pine marten (Martes americana) populations from the Yukon through to the central Northwest Territories was investigated using 11 microsatellite loci. Genetic variation within populations across the entire geographic range was relatively homogeneous as measured by: mean number of alleles (5.89 +/- 0.45) and the average unbiased expected heterozygosity (H-e) (65.6 +/- 1.7%). The overall unbiased probability of identity showed more variance between populations (1/10.25 +/- 7.84 billion) than did the mean number of alleles and the H-e estimates. Although some population structure was found among the populations, most regions were not strongly differentiated from one another. The low level of structure among the populations can, in part, be attributed to isolation by distance rather than to population fragmentation, as would be expected in more southerly regions in which suitable habitat is more disjunct. Furthermore, the low levels of population genetic structure were likely due to high levels of gene flow between regions and to large effective marten populations in the northern part of their distribution.
A population of wolverines was studied in northwestern Montana for 5 years (1972–1977). Twenty-four wolverines were captured in live traps, individually marked, and released. Ten individuals were recaptured 74 times. Twenty wolverines were fitted with radio transmitters and 576 relocations were made over a 4-year period. A minimum population size of 20 was estimated for the 1300-km2 area, or one wolverine per 65 km2. The population was believed stable. This stability was maintained by mortality and dispersal. Wolverines utilized relatively large areas. The size and shape of ranges were not affected by rivers, reservoirs, highways, or major mountain ranges. The average yearly range of male and female wolverines was 422 and 388 km2, respectively. Wolverines exhibited fidelity to a given area, but several individuals of both sexes made frequent long movements to other areas. In all instances wolverines returned to the same area. Ranges overlapped between individuals of the same and opposite sex. Territorial defense was essentially nonexisent. Wolverines scent marked to maintain spacing in time but not area. Wolverines appeared to select Abies cover types throughout the year; this selection was strongest in summer. In Montana, wilderness habitat coupled with more restrictive harvest regulations should provide for secure wolverine populations in the foreseeable future.
This is a book review by A. W. F. Edwards (published in Biometrics, 31(2) 229-230) of my books Biometry (by Sokal and Rohlf) and Statistical Tables (by Rohlf and Sokal) both published in 1981.
A measure of genetic distance (D) based on the identity of genes between populations is formulated. It is defined as D = -logeI, where I is the normalized identity of genes between two populations. This genetic distance measures the accumulated allele differences per locus. If the rate of gene substitution per year is constant, it is linearly related to the divergence time between populations under sexual isolation. It is also linearly related to geographical distance or area in some migration models. Since D is a measure of the accumulated number of codon differences per locus, it can also be estimated from data on amino acid sequences in proteins even for a distantly related species. Thus, if enough data are available, genetic distance between any pair of organisms can be measured in terms of D. This measure is applicable to any kind of organism without regard to ploidy or mating scheme.
Thesis (M. Sc.)--Simon Fraser University, 1988. Includes bibliography.
Thesis (Ph. D.)--University of Alaska, Fairbanks, 1985. Includes bibliographical references (leaves 171-178).
Thesis (M.S.)--University of Alaska, Fairbanks, 1985. Includes bibliographical references (leaves 68-73).
1.1. Plasma LDH levels are described for fifteen species of Mustelidae and two Viverridae. All species except Lutra canadensis had LDH activities two to four times higher than the human plasma control.2.2. Conepatus leuconotus (Mustelidae) and Arctictis binturong (Viverridae) were the only species examined with an LDH-1 mobility different from the human LDH-1, at 94 and 60 per cent of the control, respectively.3.3. The LDH-5 mobility of all of the carnivores was the same, and greater than that of the human control.4.4. Plasma LDH of L. canadensis and Aonyx cinerea were almost entirely in the form of LDH-1 isozyme.5.5. Some species had a unique LDH isozyme composition which easily distinguished them from other species of the family.
Mathematical formulae for the sampling variances of average heterozygosity and Nei's genetic distance are developed. These sampling variances are decomposed into their two components, i.e. the inter-locus and intra-locus variances. The relationship between the number of loci and the number of individuals per locus to be examined for estimating average heterozygosity and genetic distance is also discussed. The utility of the inter-locus variance of heterozygosity for studying the mechanism of maintenance of genetic variability in populations is indicated.
1.1. Hemoglobin samples from six-hundred and ninety-six animals representing one-hundred and twelve species and seventy-three genera of fissiped and pinniped Carnivora were examined by gel electrophoresis. All members of the Canidae, Ursidae, Procyonidae, Mustelidae, Otariidae and Phocidae had a major hemoglobin component of identical mobility.2.2. Fractionation, amino acid analysis, sulfhydryl content, peptide maps and hybrids with human hemoglobin A and dog hemoglobin indicated this hemoglobin is of identical structure in these six families.3.3. Thus, the 0·85 mobility hemoglobin has not diversified during the 45 million years since the ancestry of these families separated from the Miacidae and diverged from the Felocida during the Eocene.4.4. The hemoglobins of the Feloidea were diversified.
Measuring levels of genetic variation is an important aspect of conservation genetics. The informativeness of such measurements is related to the variability of the genetic markers used; a particular concern in species, such as bears, which are characterized by low levels of genetic variation resulting from low population densities and small effective population sizes. We describe the development of microsatellite analysis in bears and its use in assessing interpopulation differences in genetic variation in black bears from three Canadian National Parks. These markers are highly variable and allowed identification of dramatic differences in both distribution and amount of variation between populations. Low levels of variation were observed in a population from the Island of Newfoundland. The significance of interpopulation differences in variability was tested using a likelihood ratio test of estimates of theta = 4Ne mu.
Keywords:cross-species amplification;microsatellite genotyping;Mustelidae;PCR;primers
Keywords:microsatellites;Mustela erminea;Mustela vison;Mustelidae
Reproduction and natality of wolverine (Gulo gulo) in Yukon
- Banci VA
The Scientific Basis for Conserving Forest Carnivores, American Marten, Fisher, Lynx, and Wolverine in the Western United States
- Banci VA
Wild Furbearer Management and Conservation in North America
- Hash HS
Microsatellite markers for American mink (Mustela vison) and ermine (Mustela erminea)
- Flemming MA
- Ostrander EA
- Cook JA
The wolverine (Gulo gulo Linnaeus 1758) in the ecosystem
- Krott P
Wild Mammals of North America. Biology, Management and Economics
- Wilson DE
Ecology and Behaviour of Wolverine in the Yukon
- Banciva
Population characteristics. Ecology and Management of Wolverines in Northwestern Alaska
- Magounaj