Bogumiła Jędrzejewska

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.

Europe-Wide Dampening of Population Cycles in Keystone Herbivores

Cycling in Unison Many small mammals, especially voles, display semi-regular cycles of population boom and bust. Given the fundamental importance of small mammals as basal consumers and prey, such cycles can have cascading effects in trophic food webs. Cornulier et al. (p. 63) collated raw data from vole populations across Europe collected over the past 18 years. Reduction in winter growth rate was common across a wide variety of habitats with very different local climates, suggesting the presence of a continental-scale climatic driver of vole populations. Synchronicity in vole population fluctuation across Europe suggests a common climatic driver. Suggestions of collapse in small herbivore cycles since the 1980s have raised concerns about the loss of essential ecosystem functions. Whether such phenomena are general and result from extrinsic environmental changes or from intrinsic process stochasticity is currently unknown. Using a large compilation of time series of vole abundances, we demonstrate consistent cycle amplitude dampening associated with a reduction in winter population growth, although regulatory processes responsible for cyclicity have not been lost. The underlying syndrome of change throughout Europe and grass-eating vole species suggests a common climatic driver. Increasing intervals of low-amplitude small herbivore population fluctuations are expected in the future, and these may have cascading impacts on trophic webs across ecosystems.

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.

Wolf Canis lupus numbers, diet and damage to livestock in relation to hunting and ungulate abundance in northeastern Belarus during 1990–2000

Wolf Canis lupus relationships with wild ungulates, domestic animals and humans were studied in an area of ca 800 km2 at the head of the Lovat River in northeastern Belarus during 1990–2000. The region was dominated by natural habitats (78%) consisting mainly of forests and bogs, but also lakes and rivers. The abundance of wild ungulates, such as moose Alces alces, wild boar Sus scrofa, and roe deer Capreolus capreolus, as censused by snow tracking and assessed by game wardens, declined 5 to 6-fold between 1990 and 1996, most probably due to uncontrolled exploitation and poaching. During 1997–2000, the numbers of ungulates began to recover. Wolves responded to the shortage of wild ungulates by a strong shift in feeding habits. When wild ungulates were numerous, wolf diet as studied by scat analysis was composed of wild ungulates (80–88% of consumed biomass), with small additions of medium- and small-sized wild animals (7–13%), mainly beaver Castor fiber and hare Lepus sp., and domestic animals (4–6%), mainly cattle. In the years when the recorded numbers of wild ungulates were at their lowest, wolves preyed on domestic animals (38% of biomass consumed), wild ungulates (32%), and medium- and small-sized wild prey (29%). Wolf damage to domestic animals (28 head of cattle and 247 dogs killed) and wolf-human interaction (100 observations of wolves in and near villages, including one attack by a rabid wolf on 11 people) were recorded in 14 villages. The rate of wolf predation on domestic animals and their appearances in villages increased exponentially with the declining biomass of wild ungulates and ceased again when wild ungulates began to recover; a one-year time lag in wolf response to changes in ungulate abundance was observed. The numbers of wolves as estimated by snow tracking and assessed by game wardens played a weaker role in shaping wolf-livestock and wolf-human interaction. The wolf population was strongly affected by hunting during the study. Wolves responded numerically with a 1 to 2-year time lag to the varying intensity of harvest by humans. Our study showed the role of the human factor in shaping wolf numbers and wolf-livestock interaction in eastern Europe. The three major components of this relationship were: 1) the manifold decline in wild ungulate abundance, which was most probably caused by uncontrolled exploitation by humans in the years of political transformation and economic regress, made wolves shift to predation on domestic animals; inevitably, wolves were frequently seen in the rural areas; 2) people interpreted the growing rates of wolf damage and appearances near the settlements as an effect of greatly increasing numbers of wolves, and demanded that authorities and hunters fight the ‘wolf plague’; 3) hunting impact on wolves increased and led to a marked reduction in wolf numbers and a decline in wolf-human conflicts. This scenario was most probably repeated in many areas of eastern Europe during 1990–2000, which was a decade of political and economical transformation. From a management perspective, we suggested that predation levels and wolf-human conflicts could be reduced not only by increased wolf harvest but also by enhancing the density and diversity of wild ungulates.

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.