Patterns of Exposure of Iberian Wolves (<Emphasis Type="Italic">Canis lupus</Emphasis>) to Canine Viruses in Human-Dominated Landscapes

Wildlife inhabiting human-dominated landscapes is at risk of pathogen spill-over from domestic species. With the aim of gaining knowledge in the dynamics of viral infections in Iberian wolves (Canis lupus) living in anthropized landscapes of northern Spain, we analysed between 2010 and 2013 the samples of 54 wolves by serology and polymerase chain reaction (PCR) for exposure to four pathogenic canine viruses: canine distemper virus (CDV), canine parvovirus-2 (CPV), canine adenovirus 1 and 2 (CAV-1 and CAV-2) and canine herpesvirus. Overall, 76% of the studied wolves presented evidence of exposure to CPV (96% by HI, 66% by PCR) and 75% to CAV (75% by virus neutralization (VN), 76% by PCR, of which 70% CAV-1 and 6% CAV-2). This represents the first detection of CAV-2 infection in a wild carnivore. CPV/CAV-1 co-infection occurred in 51% of the wolves. The probability of wolf exposure to CPV was positively and significantly correlated with farm density in a buffer zone around the place where the wolf was found, indicating that rural dogs might be the origin of CPV infecting wolves. CPV and CAV-1 appear to be enzootic in the Iberian wolf population, which is supported by the absence of seasonal and inter-annual variations in the proportion of positive samples detected. However, while CPV may depend on periodical introductions by dogs, CAV-1 may be maintained within the wolf population. All wolves were negative for exposure to CDV (by VN and PCR) and CHV (by PCR). The absence of acquired immunity against CDV in this population may predispose it to an elevated rate of mortality in the event of a distemper spill-over via dogs.     

Does interference competition with wolves limit the distribution and abundance of coyotes?

Interference competition with wolves Canis lupus is hypothesized to limit the distribution and abundance of coyotes Canis latrans, and the extirpation of wolves is often invoked to explain the expansion in coyote range throughout much of North America. We used spatial, seasonal and temporal heterogeneity in wolf distribution and abundance to test the hypothesis that interference competition with wolves limits the distribution and abundance of coyotes. From August 2001 to August 2004, we gathered data on cause-specific mortality and survival rates of coyotes captured at wolf-free and wolf-abundant sites in Grand Teton National Park (GTNP), Wyoming, USA, to determine whether mortality due to wolves is sufficient to reduce coyote densities. We examined whether spatial segregation limits the local distribution of coyotes by evaluating home-range overlap between resident coyotes and wolves, and by contrasting dispersal rates of transient coyotes captured in wolf-free and wolf-abundant areas. Finally, we analysed data on population densities of both species at three study areas across the Greater Yellowstone Ecosystem (GYE) to determine whether an inverse relationship exists between coyote and wolf densities. Although coyotes were the numerically dominant predator, across the GYE, densities varied spatially and temporally in accordance with wolf abundance. Mean coyote densities were 33% lower at wolf-abundant sites in GTNP, and densities declined 39% in Yellowstone National Park following wolf reintroduction. A strong negative relationship between coyote and wolf densities (beta = -3.988, P < 0.005, r(2) = 0.54, n = 16), both within and across study sites, supports the hypothesis that competition with wolves limits coyote populations. Overall mortality of coyotes resulting from wolf predation was low, but wolves were responsible for 56% of transient coyote deaths (n = 5). In addition, dispersal rates of transient coyotes captured at wolf-abundant sites were 117% higher than for transients captured in wolf-free areas. Our results support the hypothesis that coyote abundance is limited by competition with wolves, and suggest that differential effects on survival and dispersal rates of transient coyotes are important mechanisms by which wolves reduce coyote densities.     

Response of Moose Hunters to Predation following Wolf Return in Sweden

Background

Predation and hunter harvest constitute the main mortality factors affecting the size and dynamics of many exploited populations. The re-colonization by wolves (Canis lupus) of the Scandinavian Peninsula may therefore substantially reduce hunter harvest of moose (Alces alces), the main prey of wolves.

Methodology/Principal findings

We examined possible effects of wolf presence on hunter harvest in areas where we had data before and after wolf establishment (n = 25), and in additional areas that had been continuously exposed to wolf predation during at least ten years (n = 43). There was a general reduction in the total number of moose harvested (n = 31,827) during the ten year study period in all areas irrespective of presence of wolves or not. However, the reduction in hunter harvest was stronger within wolf territories compared to control areas without wolves. The reduction in harvest was larger in small (500-800 km²) compared to large (1,200-1,800 km²) wolf territories. In areas with newly established wolf territories moose management appeared to be adaptive with regard to both managers (hunting quotas) and to hunters (actual harvest). In these areas an instant reduction in moose harvest over-compensated the estimated number of moose killed annually by wolves and the composition of the hunted animals changed towards a lower proportion of adult females.

Conclusions/Significance

We show that the re-colonization of wolves may result in an almost instant functional response by another large predator—humans—that reduced the potential for a direct numerical effect on the density of wolves’ main prey, the moose. Because most of the worlds’ habitat that will be available for future colonization by large predators are likely to be strongly influenced by humans, human behavioural responses may constitute a key trait that govern the impact of large predators on their prey.     

Spatial variability in wolf diet and prey selection in Galicia (NW Spain)

We studied wolf (Canis lupus) diet for three different landscapes in the north-western Iberian Peninsula, differing in land uses and availability of food for wolves. We examined 2740 scats, collected over a period of 4 years, in order to describe wolf diet, its geographic variation, and trophic preferences. The most consumed species were wild pony, roe deer and cattle. We observed differences in wolf diet among the three study sites, related to the availability and accessibility of food resources in each habitat. For the two study sites in northern and central Galicia, wolves showed similar diet, with high occurrence of wild pony (37 vs. 34%) and cattle (20 vs. 23%), but differing in the consumption of wild ungulates (16 vs. 8%) and carrion (7 vs. 14%). Wolf diet in eastern Galicia’s mountain ranges was entirely different, due to the higher consumption of wild ungulates (70%). Wolves showed clear prey selection patterns. Between wild ponies and livestock, wolves positively selected ponies. Among wild ungulates, wolves positively selected roe deer. Wild pony and roe deer are key species for wolf feeding in Galicia. In the Galician wild pony range, ponies are the main food for wolves. Given that the availability of wild ponies may contribute to the decrease in wolf predation on cattle, it is essential to develop innovative administrative decisions in such areas to preserve this traditional equid population. In the same way, the population of roe deer should be strengthened in the livestock areas outside the range of wild pony.     

Y-chromosome microsatellite variation in Italian wolves: A contribution to the study of wolf-dog hybridization patterns

One major concern in wolf (Canis lupus) conservation is the risk of genetic contamination due to crossbreeding with domestic dogs. Although genetic monitoring of wolf populations has become widely used, the behavioural mechanisms involved in wolf-dog hybridization and the detrimental effects of genetic introgression are poorly known. In this study we analysed Y-chromosome microsatellite variation in the recovering Italian wolf population and detected strikingly different allele frequencies between wolves and dogs. Four Y haplotypes were found in 74 analysed male wolves, and all of them were present in a focus wolf population in the Apennines. On the other hand, only 1 haplotype was found in the recolonizing wolf population from the Western Alps. The most common haplotype in a sample of domestic dogs, was also found in 5 wolves, 2 of which revealing a signature of recent hybridization. Moreover, another suspect hybrid carried a private haplotype of possible canine origin. These results give support to the idea that female wolves can breed with male stray dogs in the wild. The Y-chromosome variation in Italian wolves contrasts with the previously observed lack of mitochondrial variation. Further investigations are needed to clarify at what extent historical or recent wolf-dog hybridization events may have contributed to the observed haplotype diversity. In conclusion, the two molecular markers employed in this study represent effective means to trace directional genetic introgression into the wolves male lineage and have the noteworthy advantage of being suitable for analyses on low-quality DNA samples.     

Demographic effects of canine parvovirus on a free-ranging wolf population over 30 years

We followed the course of canine parvovirus (CPV) antibody prevalence in a subpopulation of wolves (Canis lupus) in northeastern Minnesota from 1973, when antibodies were first detected, through 2004. Annual early pup survival was reduced by 70%, and wolf population change was related to CPV antibody prevalence. In the greater Minnesota population of 3,000 wolves, pup survival was reduced by 40-60%. This reduction limited the Minnesota wolf population rate of increase to about 4% per year compared with increases of 16-58% in other populations. Because it is young wolves that disperse, reduced pup survival may have caused reduced dispersal and reduced recolonization of new range in Minnesota.     

To Eat or Not To Eat? The Diet of the Endangered Iberian Wolf (Canis lupus signatus) in a Human-Dominated Landscape in Central Portugal

Livestock predation by large carnivores and their persecution by local communities are major conservation concerns. In order to prevent speculations and reduce conflicts, it is crucial to get detailed and accurate data on predators’ dietary ecology, which is particularly important in human dominated landscapes where livestock densities are high. This is the case of the endangered Iberian wolf in Portugal, an endemic subspecies of the Iberian Peninsula, which has seen its population distribution and abundance decline throughout the 20th century. Accordingly, the diet of the Iberian wolf was analyzed, using scat analysis, in a humanized landscape in central Portugal. From 2011 to 2014, a total of 295 wolf scats were collected from transects distributed throughout the study area, prospected on a monthly basis. Scat analysis indicated a high dependence of Iberian wolf on livestock. Domestic goat predominated the diet (62% of the scats), followed by cow (20%) and sheep (13%); the only wild ungulate present in the scat analysis was the wild boar (4% of the scats). Our results show that even though livestock constitute most part of wolves diet, different livestock species may represent different predation opportunities. We conclude that the high levels of livestock consumption may be a result of low diversity and density of wild ungulates that settles livestock as the only abundant prey for wolves. Our findings help on the understanding of the Iberian wolf feeding ecology and have implications for conflict management strategies. Finally, management implications are discussed and solutions are recommended.     

Ecosystem Scale Declines in Elk Recruitment and Population Growth with Wolf Colonization: A Before-After-Control-Impact Approach

The reintroduction of wolves (Canis lupus) to Yellowstone provided the unusual opportunity for a quasi-experimental test of the effects of wolf predation on their primary prey (elk – Cervus elaphus) in a system where top-down, bottom-up, and abiotic forces on prey population dynamics were closely and consistently monitored before and after reintroduction. Here, we examined data from 33 years for 12 elk population segments spread across southwestern Montana and northwestern Wyoming in a large scale before-after-control-impact analysis of the effects of wolves on elk recruitment and population dynamics. Recruitment, as measured by the midwinter juvenile∶female ratio, was a strong determinant of elk dynamics, and declined by 35% in elk herds colonized by wolves as annual population growth shifted from increasing to decreasing. Negative effects of population density and winter severity on recruitment, long recognized as important for elk dynamics, were detected in uncolonized elk herds and in wolf-colonized elk herds prior to wolf colonization, but not after wolf colonization. Growing season precipitation and harvest had no detectable effect on recruitment in either wolf treatment or colonization period, although harvest rates of juveniles∶females declined by 37% in wolf-colonized herds. Even if it is assumed that mortality due to predation is completely additive, liberal estimates of wolf predation rates on juvenile elk could explain no more than 52% of the total decline in juvenile∶female ratios in wolf-colonized herds, after accounting for the effects of other limiting factors. Collectively, these long-term, large-scale patterns align well with prior studies that have reported substantial decrease in elk numbers immediately after wolf recolonization, relatively weak additive effects of direct wolf predation on elk survival, and decreased reproduction and recruitment with exposure to predation risk from wolves.     

Insights into wolf presence in human‐dominated landscapes: the relative role of food availability,humans and landscape attributes

Aim Understanding which human or environmental factors interact to enable or to limit the occurrence and persistence of large carnivores in human‐dominated landscapes is an important issue for their effective conservation, especially under the current scenario of global change where most of their former habitat is being transformed by humans. Location NW Iberian Peninsula. Methods We combine data on the distribution of Iberian wolves (Canis lupus signatus) living in a human‐dominated landscape in NW Spain and variation and partitioning methods to investigate the relative importance of three groups of predictors: food availability, humans and landscape attributes – each group expected to have unequal effects on wolf reproduction and survival – and their interactions on the occurrence of this species. Results We found that the group of predictors related with landscape attributes (altitude, roughness and refuge) strongly determined wolf occurrence, followed by humans and food availability. Variance partitioning analysis revealed that the three most important components determining wolf occurrence were related with landscape attributes: (1) the joint effects of the three predictor groups, (2) the joint effect of humans and landscape attributes and (3) the pure effect of landscape attributes. Altitude had the main independent contribution to explain the probability of wolf occurrence. Main conclusions In human‐dominated landscapes, the occurrence of wolves is the result of a complex interaction among several environmental and human factors. Our results suggest that the characteristics of the landscape (spatial context) – factors associated with the security of wolves facilitating that animals go unnoticed by humans, wolf movements, dispersal events and short‐time colonization – become more important in human‐dominated landscapes and may have played a key role in the occurrence and persistence of this species throughout decades modulating the relationship between humans and wolf distribution.     

Sympatric snow leopards and Tibetan wolves: coexistence of large carnivores with human-driven potential competition

The snow leopard Panthera uncia coexists with the wolf Canis lupus throughout most of its distribution range. We analysed the food habits of snow leopards and wolves in their sympatric range in the Karakoram mountains of Pakistan. A total of 131 genotyped scats (N?=?74, snow leopard; N?=?57, Tibetan wolf) were collected during the cold periods (i.e. winter and spring) of 2011 and 2012 in the Hushey valley. Large mammals, i.e. livestock and ibex, accounted for 84.8 and 83.1% of the diet (relative frequency) of the snow leopard and the wolf, respectively. Domestic prey was the staple of the diet of both snow leopards (66.6%) and wolves (75.1%). Ibex Capra ibex, the only wild ungulate in our study area, contributed 18.2 and 16.9% of relative frequencies in the diets of the snow leopard and the wolf, respectively. In winter, the snow leopard heavily relied on domestic sheep (43.3%) for food, whereas the wolf preyed mainly on domestic goats (43.4%). Differently from other study areas, both snow leopards and wolves showed no apparent prey preference (Jacobs index: snow leopard min. ??0.098, max. 0.102; Tibetan wolf min. ??0.120, max. 0.03). In human depauperate areas, with livestock and only a few wild prey, should competitive interactions arise, two main scenarios could be expected, with either predator as a winner. In both cases, the best solution could primarily impinge on habitat restoration, so that a balance could be found between these predators, who have already coexisted for thousands of years.     

On the path to extinction: Inbreeding and admixture in a declining grey wolf population

Allee effects reduce the viability of small populations in many different ways, which act synergistically to lead populations towards extinction vortexes. The Sierra Morena wolf population, isolated in the south of the Iberian Peninsula and composed of just one or few packs for decades, represents a good example of how diverse threats act additively in very small populations. We sequenced the genome of one of the last wolves identified (and road‐killed) in Sierra Morena and that of another wolf in the Iberian Wolf Captive Breeding Program and compared them with other wolf and dog genomes from around the world (including two previously published genome sequences from northern Iberian wolves). The results showed relatively low overall genetic diversity in Iberian wolves, but diverse population histories including past introgression of dog genes. The Sierra Morena wolf had an extraordinarily high level of inbreeding and long runs of homozygosity, resulting from the long isolation. In addition, about one‐third of the genome was of dog origin. Despite the introgression of dog genes, heterozygosity remained low because of continued inbreeding after several hybridization events. The results thus illustrate the case of a small and isolated wolf population where the low population density may have favoured hybridization and introgression of dog alleles, but continued inbreeding may have resulted in large chromosomal fragments of wolf origin completely disappearing from the population, and being replaced by chromosomal fragments of dog origin. The latest population surveys suggest that this population may have gone extinct.     

Habitat variables associated with wolf (Canis lupus) distribution and abundance in northern Poland

Based on data collected during the National Wolf Census in 2000–01, we analysed the main habitat factors influencing the distribution and abundance of the wolf, Canis lupus, in northern Poland. The study region forms the western border of the continuous Eastern European range of wolves, although attempts at westward dispersal have been observed. Using Geographic Information System techniques, we measured nine habitat variables and three parameters related to wolf occurrence in 134 circular sample plots (radius 7 km, area 154 km² each). We compared 72 plots where wolves were recorded and 62 plots with no signs of wolf presence. Wolf plots were characterized by significantly higher forest cover, less fragmentation of forests, lower density of villages, towns, motorways, and railways than wolf‐free plots. We found a positive correlation between the sum of wolf observations in plots and forest cover. The number of domestic animals killed by wolves was higher in areas with higher indices of wolf abundance and lower forest area. In multiple regression analysis, four independent variables explained 59% of the variation in wolf distribution and abundance in northern Poland: straight‐line distance to continuous range of wolves in Eastern Europe; forest cover; forest fragmentation; and length of major motorways. We conclude that protection of wolves in Poland (since 1998) may not be an adequate conservation measure, especially because of the increasing density of highways and express motorways. Existing forest corridors should be protected and new ones should be restored to ensure long‐term conservation of wolves and allow range expansion into Western Europe.     

Simulating the impact of socio-economic trends on threatened Iberian wolf populations Canis lupus signatus in north-eastern Portugal

The IP4 highway and the new projected road network have been changing the critical Iberian wolf (Canis lupus signatus) habitat in Trás-os-Montes e Alto Douro region (north-eastern Portugal). A holistic stochastic dynamic methodology (SDM) was developed for predicting changes in Iberian wolf population due to the new highways construction, increasing road traffic density and urbanization. The ecological indicators for wolf presence and abundance were estimated indirectly from the density of attacks on livestock. The low density of wild ungulates in the area makes livestock the main source of food for wolves. These indirect ecological indicators and state variables are the underlying database of our SDM model. This model focus on the interactions between conceptually isolated key-components, such as the density of attacks on livestock and changes in habitat conditions, providing some basis to analyse the responses of wolf populations to the environmental scenarios that will characterize the region in the future. The model proposed was preceded by a conventional multivariate statistical procedure (stepwise multiple regression analysis) performed to discriminate the significant relationships between livestock attacks and socio-environmental variables. The holistic parameters of the model were estimated from the results of the statistical treatment and from regional data regarding tendencies within the use of land. The simulation results demonstrate the SDM capability in capturing the trends of this changing region, namely by showing a dramatically decrease of wolf attacks in the region for the next decade.     

The forgotten prey of an iconic predator: a review of interactions between grey wolves Canis lupus and beavers Castor spp.

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Planning and Implementing a Reintroduction of Wolves to Yellowstone National Park and Central Idaho

The Northern Rocky Mountain Wolf Recovery plan proposed reintroduction of Canis lupus (gray wolf) to Yellowstone National Park and central Idaho as part of a wolf restoration plan for the northern Rocky Mountains of the United States. Strong opposition from some factions within the region forestalled the action for two decades. An environmental impact statement, conducted in 1992–1994 with extensive public input, culminated in a proposal to reintroduce wolves designated as “non-essential—experimental” under Section 10 (j) of the federal Endangered Species Act. This approach, approved by the Secretary of the Interior in 1994, provided for wolf restoration while allowing management flexibility to deal with concerns of the local public. A reintroduction plan was developed in the summer and fall of 1994. Acquiring, holding, transporting, and releasing suitable wolves for reintroduction presented a myriad of technical and logistical challenges that required effective planning and coordination by all participants. In January 1995, 29 wolves were captured in Alberta and transported to Yellowstone National Park (14) and central Idaho (15). Idaho wolves were freed immediately upon arrival; Yellowstone wolves (three family groups) were held in acclimation pens in the park until late March. Most Idaho wolves traveled extensively within the area intended for them, averaging 82 km net distance away from release sites after 5 months (range = 30–220 km), and three male-female pairs formed by July. After 5 months in the wild, at least 13 of 15 Idaho-released wolves were alive within the intended area, as were 13 of 14 Yellowstone wolves; one wolf was known to have been illegally killed in each area. No livestock were killed. Wolves released into Yellowstone Park continued to live as packs, stayed closer to their release sites (x = 22 km at end of June), and settled into home ranges; two packs produced a total of nine pups. The progress of the reintroduction program in its first year far exceeded expectations. Reintroductions of about 15 wolves to each area for 2–4 more years are scheduled, but the project may be shortened because of early successes. Future reintroduction planners can expect sociocultural issues to pervade the effort, but they can be optimistic that, from a biological standpoint, reintroduction of wolves has strong potential as a restoration technique.     

Seasonal and biogeographical patterns of gastrointestinal parasites in large carnivores: wolves in a coastal archipelago

Parasites are increasingly recognized for their profound influences on individual, population and ecosystem health. We provide the first report of gastrointestinal parasites in gray wolves from the central and north coasts of British Columbia, Canada. Across 60 000 km(2), wolf feces were collected from 34 packs in 2005-2008. At a smaller spatial scale (3300 km(2)), 8 packs were sampled in spring and autumn. Parasite eggs, larvae, and cysts were identified using standard flotation techniques and morphology. A subset of samples was analysed by PCR and sequencing to identify tapeworm eggs (n=9) and Giardia cysts (n=14). We detected ≥14 parasite taxa in 1558 fecal samples. Sarcocystis sporocysts occurred most frequently in feces (43·7%), followed by taeniid eggs (23·9%), Diphyllobothrium eggs (9·1%), Giardia cysts (6·8%), Toxocara canis eggs (2·1%), and Cryptosporidium oocysts (1·7%). Other parasites occurred in ≤1% of feces. Genetic analyses revealed Echinococcus canadensis strains G8 and G10, Taenia ovis krabbei, Diphyllobothrium nehonkaiense, and Giardia duodenalis assemblages A and B. Parasite prevalence differed between seasons and island/mainland sites. Patterns in parasite prevalence reflect seasonal and spatial resource use by wolves and wolf-salmon associations. These data provide a unique, extensive and solid baseline for monitoring parasite community structure in relation to environmental change.     

Helminth parasites of wolves (Canis lupus): a species list and an analysis of published prevalence studies in Nearctic and Palaearctic populations

A literature survey was undertaken in order to draw up a definitive list of helminth parasites of the wolf, Canis lupus. From 27 papers a total of 72 helminth species from 40 genera were recorded that infect wolves, of which 93% were identified from the gastrointestinal tract at necropsy. They comprised 28 species of nematode, 27 species of cestode, 16 species of trematode and one acanthocephalan. Of these, 46 species were able to be included in further meta-analysis of prevalence data derived from 25 publications for which the total number of wolves examined was 1282 (1066 from Nearctic populations, and 216 from the Palaearctic region). These two populations were further subdivided into three relevent ecosystems or biomes, i.e. temperate/montane (n=216), boreal (n=805) or tundra (n=261). The meta-analysis of relative prevalence indicated the most common helminth species to be the tapeworm Taenia hydatigena, which occurred at relative rates of >30% for either zoogeographic region as well as in each of the three biomes. The related tapeworm, Echinococcus granulosus also exhibited high meta-prevalence (>19%) in all host biomes. The hookworm Uncinaria stenocephala was the most prevalent nematode species by meta-analysis (meta-prevalence 44.9%) in the temperate/montane biome, while the ascarid Toxascaris leonina was the dominant helminth species (meta-prevalence 73.9%) in the tundra wolf populations. Trematodes in the genus Alaria were the dominant fluke (meta-prevalence 3-5%) in all biomes. Analysis of published studies for helminth biodiversity using the Shannon-Wiener index based on species number and meta-prevalence by region or biome, indicated that highest helminth diversity occurred in wolf populations of the temperate/ montane biome (Palaearctic), and was lowest in tundra wolf populations of the Nearctic (P<0.05). Helminth species assemblage in European wolf populations was therefore at least as great or more varied than was recorded for the larger less disturbed wolf populations of North America.     

Genetic assessment of the Iberian wolf Canis lupus signatus captive breeding program

The main goal of ex situ conservation programs is to improve the chances of long term survival of natural populations by founding and managing captive colonies that can serve as a source of individuals for future reintroductions or to reinforce existing populations. The degree in which a captive breeding program has captured the genetic diversity existing in the source wild population has seldom been evaluated. In this study we evaluate the genetic diversity in wild and captive populations of the Iberian wolf, Canis lupus signatus, in order to assess how much genetic diversity is being preserved in the ongoing ex situ conservation program for this subspecies. A sample of domestic dogs was also included in the analysis for comparison. Seventy-four wolves and 135 dogs were genotyped at 13 unlinked microsatellite loci. The results show that genetic diversity in Iberian wolves is comparable in magnitude to that of other wild populations of gray wolf. Both the wild and the captive Iberian wolf populations have a similarly high genetic diversity indicating that no substantial loss of diversity has occurred in the captive-breeding program. The effective number of founders of the program was estimated as ∼ ∼16, suggesting that all founders in the studbook pedigree were genetically independent. Our results emphasize also the genetic divergence between wolves and domestic dogs and indicate that our set of 13 microsatellite loci provide a powerful diagnostic test to distinguish wolves, dogs and their hybrids.     

Differentiation of tundra/taiga and boreal coniferous forest wolves: genetics, coat colour and association with migratory caribou

The grey wolf has one of the largest historic distributions of any terrestrial mammal and can disperse over great distances across imposing topographic barriers. As a result, geographical distance and physical obstacles to dispersal may not be consequential factors in the evolutionary divergence of wolf populations. However, recent studies suggest ecological features can constrain gene flow. We tested whether wolf-prey associations in uninterrupted tundra and forested regions of Canada explained differences in migratory behaviour, genetics, and coat colour of wolves. Satellite-telemetry data demonstrated that tundra wolves (n = 19) migrate annually with caribou (n = 19) from denning areas in the tundra to wintering areas south of the treeline. In contrast, nearby boreal coniferous forest wolves are territorial and associated year round with resident prey. Spatially explicit analysis of 14 autosomal microsatellite loci (n = 404 individuals) found two genetic clusters corresponding to tundra vs. boreal coniferous forest wolves. A sex bias in gene flow was inferred based on higher levels of mtDNA divergence (F(ST) = 0.282, 0.028 and 0.033; P < 0.0001 for mitochondrial, nuclear autosomal and Y-chromosome markers, respectively). Phenotypic differentiation was substantial as 93% of wolves from tundra populations exhibited light colouration whereas only 38% of boreal coniferous forest wolves did (chi(2) = 64.52, P < 0.0001). The sharp boundary representing this discontinuity was the southern limit of the caribou migration. These findings show that substantial genetic and phenotypic differentiation in highly mobile mammals can be caused by prey-habitat specialization rather than distance or topographic barriers. The presence of a distinct wolf ecotype in the tundra of North America highlights the need to preserve migratory populations.     

Hybridization between wolf and domestic dog: First evidence from an endangered population in central Portugal

Human population expansion has promoted contact between wildlife and domestic animals with severe ecological consequences, such as anthropogenic hybridization. In Portugal, Iberian wolf (Canis lupus signatus) populations are considered “Endangered” and co-habit with humans so the risks of hybridization with free-ranging dogs, and livestock depredation can be particularly high. Our aim was to report the occurrence of wolf-dog hybridization in an endangered Iberian wolf sub-population, located in the south of the Douro river, Portugal. We used mitochondrial DNA and microsatellite data to investigate putative hybrids between Iberian wolves and dogs. Here, we report for the first time a wolf-dog hybrid located in the south of the Douro river. This is the second hybrid found in Portugal, and even if hybridization cases are still considered rare, they can be particularly problematic in isolated, fragmented and endangered populations, such as the one studied here. Appropriate management and conservation measures are recommended.