Włodzimierz Jędrzejewski

Genome-wide SNP and haplotype analyses reveal a rich history underlying dog domestication

Advances in genome technology have facilitated a new understanding of the historical and genetic processes crucial to rapid phenotypic evolution under domestication. To understand the process of dog diversification better, we conducted an extensive genome-wide survey of more than 48,000 single nucleotide polymorphisms in dogs and their wild progenitor, the grey wolf. Here we show that dog breeds share a higher proportion of multi-locus haplotypes unique to grey wolves from the Middle East, indicating that they are a dominant source of genetic diversity for dogs rather than wolves from east Asia, as suggested by mitochondrial DNA sequence data. Furthermore, we find a surprising correspondence between genetic and phenotypic/functional breed groupings but there are exceptions that suggest phenotypic diversification depended in part on the repeated crossing of individuals with novel phenotypes. Our results show that Middle Eastern wolves were a critical source of genome diversity, although interbreeding with local wolf populations clearly occurred elsewhere in the early history of specific lineages. More recently, the evolution of modern dog breeds seems to have been an iterative process that drew on a limited genetic toolkit to create remarkable phenotypic diversity.

A genome-wide perspective on the evolutionary history of enigmatic wolf-like canids

High-throughput genotyping technologies developed for model species can potentially increase the resolution of demographic history and ancestry in wild relatives. We use a SNP genotyping microarray developed for the domestic dog to assay variation in over 48K loci in wolf-like species worldwide. Despite the high mobility of these large carnivores, we find distinct hierarchical population units within gray wolves and coyotes that correspond with geographic and ecologic differences among populations. Further, we test controversial theories about the ancestry of the Great Lakes wolf and red wolf using an analysis of haplotype blocks across all 38 canid autosomes. We find that these enigmatic canids are highly admixed varieties derived from gray wolves and coyotes, respectively. This divergent genomic history suggests that they do not have a shared recent ancestry as proposed by previous researchers. Interspecific hybridization, as well as the process of evolutionary divergence, may be responsible for the observed phenotypic distinction of both forms. Such admixture complicates decisions regarding endangered species restoration and protection.

KILL RATES AND PREDATION BY WOLVES ON UNGULATE POPULATIONS IN BIAŁOWIEŻA PRIMEVAL FOREST (POLAND)

Wolf (Canis lupus) kill rates, factors affecting their variation, and predation impact on ungulates were studied in the Polish part of Biaowieza Primeval Forest (580 km 2 ). With the mean size of hunting groups being 4.4 individuals, wolves killed, on average, 0.513 6 0.04 prey·(pack) 21 ·d 21 (mean 6 1 SE); 63% of prey were red deer (Cervus elaphus), 28% were wild boar (Sus scrofa), and 4% were roe deer (Capreolus capreolus). Per capita kill rate averaged 0.116 ungulates·(wolf) 21 ·d 21 , and daily food intake was 5.58 6 0.32 kg·(wolf) 21 ·d 21 . Kill rate on red deer was affected by snow cover (P , 0.001). A pack of wolves killed, on average, 0.264 deer/d in seasons with no snow and 0.587 deer/d when snow was 17 cm deep. The increase in kill rates coincided with a decline in the condition of juvenile (but not adult) deer in late winter (mean marrow fat content in the femur 66% in October-January vs. 27% in February-March). Per capita kill rates decreased slightly (not significantly) with the increasing size of wolf hunting group. However, the amount of food acquired per wolf did not differ among groups containing 2-6 individuals, because larger packs killed bigger prey more often and small prey less frequently than did small packs. Wolf kill rates on wild boar were higher in spring-summer (0.242 6 0.06 boar·(pack) 21 ·d 21 ), when piglets were present, than in autumn-winter (0.106 6 0.04 boar·(pack) 21 ·d 21 ). Annually, wolves killed on average 72 red deer, 16 roe deer, and 31 wild boar over a 100-km 2 area. Compared to prey densities, wolves were an important agent of mortality for red deer only, taking annually 12% of spring-summer (seasonally highest) numbers of deer, which was equivalent to 40% of deer annual increase due to breeding and 40% of their annual mortality. Compared to winter densities (3-6 deer/km 2 ), percentage predation by wolves was inversely density dependent; thus wolves limited deer numbers but did not regulate prey population. By eliminating a substantial proportion of the annual production of the deer population, wolves hamper its growth and prolong the time until it reaches carrying capacity of the habitat. However, wolf predation alone is a poor predictor of deer population dynamics, because deer are also subject to lynx (Lynx lynx) predation and hunting harvest.

Ecological factors influence population genetic structure of European grey wolves

Although the mechanisms controlling gene flow among populations are particularly important for evolutionary processes, they are still poorly understood, especially in the case of large carnivoran mammals with extensive continuous distributions. We studied the question of factors affecting population genetic structure in the grey wolf, Canis lupus, one of the most mobile terrestrial carnivores. We analysed variability in mitochondrial DNA and 14 microsatellite loci for a sample of 643 individuals from 59 localities representing most of the continuous wolf range in Eastern Europe. We tested an array of geographical, historical and ecological factors to check whether they may explain genetic differentiation among local wolf populations. We showed that wolf populations in Eastern Europe displayed nonrandom spatial genetic structure in the absence of obvious physical barriers to movement. Neither topographic barriers nor past fragmentation could explain spatial genetic structure. However, we found that the genetic differentiation among local populations was correlated with climate, habitat types, and wolf diet composition. This result shows that ecological processes may strongly influence the amount of gene flow among populations. We suggest natal‐habitat‐biased dispersal as an underlying mechanism linking population ecology with population genetic structure.

Spatiotemporal segregation of wolves from humans in the bialowieza forest (POLAND)

Knowledge about the impact of human activity on the behavior of wolves (Canis lupus) is important to predict habitats suitable for wolf recolonization and for planning management zones. We tested the hypothesis that wolves live spatiotemporally segregated from humans. From 1994 to 1999, we radiotracked 11 wolves in 4 packs and monitored human activity in the Bialowieza Forest, Poland. Wolves avoided permanent human-made structures (settlements, forest edge to arable land, roads, tourist trails) more in the day than at night. Wolf avoidance increased with increasing human use. Particularly large settlements and intensively used public roads reduced the area used by wolves. Wolves avoided human presence in the forest (traffic, forestry operations) by temporarily selecting areas where people were absent. One of the wolf packs selected a national park zone with restriced access (50 km 2 ) as the core area of its home range in both day and night. Conversely, wolf packs living in a commercial forest with small nature reserves (≤4 km 2 ) did not select reserves in the day or night. We concluded that spatiotemporal segregation is an adaptation of wolves to coexist with humans while keeping their activity pattern optimized toward food acquisition. The distribution of areas with restricted human access, forest, settlements, and intensively used public roads are important factors determining the suitability of an area for wolves.

Weasel Population Response, Home Range, and Predation on Rodents in a Deciduous Forest in Poland

Numerical responses of the weasel Mustela nivalis to the changes in population density of forest rodents (bank vole Clethrionomys glareolus and yellow-necked mouse Apodemus flavicollis) and predation by weasels were studied in the pristine deciduous forests of Bialowieza National Park, eastern Poland, in 1985 through 1992. The rodents experienced 5 yr of noncyclic (seasonal) fluctuations (autumn density 23-74 rodents/ha) and 2 yr of outbreak and crash (triggered by synchronous heavy crop of oak, hornbeam, and maple seeds). Autumn numbers of rodents exceeded 300 individuals/ha during the outbreak and dropped to 8 individuals/ha in the following autumn. Weasels were censused by livetrapping in summer and by snowtracking on an 11.2-km 2 grid of transects in winter. Radiotracking of 12 weasels in 1990 and 1991 yielded estimates of home ranges and daily movement distances, which were combined with snowtracking and livetrapping data to estimate densities during 7 yr. Estimated winter density of weasels varied from 5.2 to 27.3 individuals/10 km 2 in December and declined to 0-19.1 individuals/10 km 2 by early spring (March). Midsummer (July/August) indices of weasel numbers were extremely variable and corresponded to 41.9-47.6 individuals/10 km 2 in years with moderate density of rodents, 101.7 individuals/10 km 2 during the rodent outbreak and 19.1 individuals/10 km 2 during the crash. Increase of weasel numbers from spring to midsummer was positively related to the spring numbers of rodents. Autumn and winter decline of weasel numbers was not related to rodent density changes. During the outbreak and crash of the rodent population, the numbers of weasels and rodents (both sampled at 2-3 mo intervals) were positively correlated (P < 0.0005) with no time lag. Home ranges of male weasels radiotracked during the rodent outbreak were 11-37 ha (minimum convex polygon), compared to 117-216 ha during the crash year. The predator/prey ratio varied from 0 to 2.5 weasels/1000 rodents. The ratio was highest at low densities of rodents. With increasing numbers of rodents, the ratio declined, since rodent population growth was overwhelmingly faster than weasel population growth. In the 7 autumn-winter seasons (1 October-15 April), weasels removed, on average, 1.6 to 9.5 rodents from each hectare, i.e., from 2 to 28% of autumn numbers of rodents. Winter predation by weasels was heaviest at rodent density of 20 individuals/ha. At lower densities of rodents, the number of weasels was restricted by food shortage and the role of their predation rapidly declined. At high rodent densities, the rodent numbers by far exceeded the predatory capacity of weasels and predation percentage declined again. Weasel predation in relation to rodent density has the same pattern in geographic zones ranging from Turkmen deserts to European farmlands and forests.

Home ranges of wolves in Białowieża Primeval Forest, Poland, compared with other Eurasian populations

Home-range size, its seasonal variation, and pattern of home-range use of wolves ( Canis lupus ) were studied in Bialowieėa Primeval Forest (BPF) located on the Polish-Belarussian borderland in 1994–1996. In the Belarussian part of BPF where wolves were hunted, their winter density was 0.9–1.5 individuals/100 km2, and mean pack size was 2.7–3.2 wolves. In the Polish part of BPF where wolves were protected, their densities were 2–2.6 individuals/100 km2, and mean pack size was four to five wolves. In spring-summer, wolves usually moved singly or in pairs (65% of observations), but in autumn-winter, 51% of seen or snowtracked groups were whole packs. In 1994–1996, four wolves belonging to two neighbouring packs of five to seven individuals each were radiotracked in the Polish part of BPF for 4–18 months. Their total home ranges, estimated by the minimum convex polygon method with 100% of locations, covered 173–294 km2. Core areas of home ranges, comprising 50% of locations, were small: 11–23 km2, or 5–13% of the total home ranges. Packs hunted both in core areas and peripheral parts of the ranges, but the majority of their diurnal resting sites were located in core areas. Home ranges of wolves were 141–168 km2 in spring-summer (May-September) and 99–271 km2 in autumn-winter (October-April). There was nearly no overlap of the two packs’ home ranges (0–3% in various seasons). Variation in the size of seasonal home range was observed for two breeding females. During parturition and early nursing in May–June, they confined their activity to an average of 17 km2. Literature on sizes of home ranges of Eurasian wolves was reviewed. Home ranges of wolves increased from 80–240 km2 in southern and central Europe to 415–500 km2 in northern Scandinavia. Smallest ranges were reported from regions where red deer ( Cervus elaphus ) were common. The population status of wolves affected size of their ranges; they were large in low-density colonizing populations and small in established populations.

Phylogeographic history of grey wolves in Europe

BackgroundWhile it is generally accepted that patterns of intra-specific genetic differentiation are substantially affected by glacial history, population genetic processes occurring during Pleistocene glaciations are still poorly understood. In this study, we address the question of the genetic consequences of Pleistocene glaciations for European grey wolves. Combining our data with data from published studies, we analysed phylogenetic relationships and geographic distribution of mitochondrial DNA haplotypes for 947 contemporary European wolves. We also compared the contemporary wolf sequences with published sequences of 24 ancient European wolves.ResultsWe found that haplotypes representing two haplogroups, 1 and 2, overlap geographically, but substantially differ in frequency between populations from south-western and eastern Europe. A comparison between haplotypes from Europe and other continents showed that both haplogroups are spread throughout Eurasia, while only haplogroup 1 occurs in contemporary North American wolves. All ancient wolf samples from western Europe that dated from between 44,000 and 1,200 years B.P. belonged to haplogroup 2, suggesting the long-term predominance of this haplogroup in this region. Moreover, a comparison of current and past frequencies and distributions of the two haplogroups in Europe suggested that haplogroup 2 became outnumbered by haplogroup 1 during the last several thousand years.ConclusionsParallel haplogroup replacement, with haplogroup 2 being totally replaced by haplogroup 1, has been reported for North American grey wolves. Taking into account the similarity of diets reported for the late Pleistocene wolves from Europe and North America, the correspondence between these haplogroup frequency changes may suggest that they were associated with ecological changes occurring after the Last Glacial Maximum.

Scavenging on European bison carcasses in Bialowieza Primeval Forest (eastern Poland)

Abstract We investigated the utilization of European bison, Bison bonasus, carcasses by the scavenging guild in Bialowieza Primeval Forest (eastern Poland) during 1997-2001. Twelve carcasses were monitored in systematic visits till total depletion (N=303). Thirteen species of birds and mammals utilized bison carcasses. Most frequent scavengers and their mean scavenging frequencies (mean percentage of visits to each carcass with a given scavenger species recorded) were raven, Corvus corax, 72% red fox, Vulpes vulpes, 41% wolf, Canis lupus, 29% common buzzard, Buteo buteo, 23% raccoon dog, Nyctereutes procyonoides, 20% and white-tailed eagle, Haliaeetus albicilla, 16%. Ravens and white-tailed eagles were observed significantly more often at carcasses placed in clearings than at those exposed in the forest. The opposite was recorded for raccoon dogs. Manifest habitat segregation was also found for flocks of immature ravens and territorial pairs. Wolves had an important facilitation effect for other species and triggered their scavenging activity. Bison carcasses were utilized for an average of 106 ± 61 days (mean ± SD), to over 80% of live weight consumed. The estimated mean daily consumption by all scavengers was 3 kg day-1 (range 0-68), being highest during the first 2 weeks (6.8 ± 6.2 kg day-1). The utilization time of bison carcasses depended on the index of carcass openness, the number of wolf feeding visits to the carcass, the date of carcass exposure, and the habitat type (forest versus open clearings). Ambient temperature had a significant effect on the rate of carcass depletion, while the effects of snow cover and precipitation were negligible.

Spatiotemporal behavioral plasticity of wild boar (Sus scrofa) under contrasting conditions of human pressure: primeval forest and metropolitan area

Abstract The aim of this study was to examine the effects of sex and age of individuals, season, and human pressure (both human presence and habitat structure) on spatiotemporal behavior of wild boar (Sus scrofa). Specifically, we compared wild boar behavior under contrasting conditions of human pressure, within the primeval temperate forest of Białowieża (eastern Poland) and the metropolitan area of Cracow (Poland). It was predicted that, compared with the forest, wild boar within the urban area will have smaller home ranges due to restricted space, will show longer daily movements due to patchy resources, and will exhibit increased nocturnal activity and ranging behavior in an attempt to avoid human interference. We used radiotracking data from 35 wild boar. Animals inhabiting the urban area had smaller home ranges, yet covered almost twice as much distance on a daily basis than individuals inhabiting primeval forest. Daily duration of activity was similar in the 2 study areas. However, distribution of activity throughout the day differed considerably. In the urban area wild boar were almost exclusively nocturnal, whereas in the primeval forest wild boar activity was evenly distributed throughout the day. Additionally, in the urban area, activity was strongly associated with traveling speed, whereas in the primeval forest active wild boar moved about to little extent. Seasonal effects were stronger in the primeval forest and affected daily distance traveled, duration of activity, and level of diurnality. This study showed that wild boar can adjust their spatiotemporal behavior to local conditions and this may be one factor explaining recent rapid demographic expansion in Europe.