Krzysztof Schmidt

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.

PREY SELECTION AND PREDATION BY WOLVES IN BIAŁOWIEŻA PRIMEVAL FOREST, POLAND

Abstract Relationships of wolves (Canis lupus) and ungulates were studied in the Polish part of Białowieża Primeval Forest with high densities of prey. The number of wolves ranged from 7 to 19, and the number of packs ranged from 2 to 4. Average densities were 2.3 wolves/100 km2. Red deer (Cervus elaphus) was the main prey of wolves. Roe deer (Capreolus capreolus), wild boar (Sus scrofa), moose (Alces alces), and European bison (Bison bonasus) were hunted less than expected based on their abundance. Mean mass of ungulates killed by wolves was 55 kg. Prey were consumed quickly, with 57% of kills completely eaten on the 1st day after killing. Average killing rate by wolves was 0.78 ungulate per wolf pack per day (0.14 prey item per wolf per day). Results of this study combined with the data obtained in the Belarussian part of Białowieża Primeval Forest in 1946–1985 allowed for analysis of dietary response of wolves to changes in densities of ungulates. Wolves showed a response to abundance of red deer. The amount of other ungulates in their diet depended on the densities of red deer. From 1991 to 1996, wolves annually removed 57–105 red deer, 19–38 wild boar, 19–25 roe deer, and 0–2 moose per 100 km2. Those amounts were equivalent to 9–13% of spring–summer densities of red deer, 4–8% of wild boar, 3–4% of roe deer, and 0–29% of moose. Additionally, hunters annually harvested 131–140 red deer, 44–114 roe deer, 1–7 moose, and 45–142 wild boar per 100 km2. Effects of predation and harvest by hunters on ungulate mortality were likely additive and caused declines in ungulate populations during our study.

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.

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.

Hunting for fear: innovating management of human–wildlife conflicts

Summary 1. There is a growing theoretical basis for the role of predation risk as a driver of trophic interactions, conceptualized as the ‘ecology of fear’. However, current ungulate management ignores the role of nonlethal risk effects of predation. 2. We introduce the concept of ‘hunting for fear’ as an extension of the more classical ‘hunting to kill’ that is typically used in large herbivore management. Hunting for fear aims to induce a behavioural response in ungulates, for example, as a way of diverting them from areas where their impact is undesired. 3. Synthesis and applications. Hunting for fear asks for novel, potentially controversial, ways of hunting to induce strong enough risk effects, including more hunting on foot and with dogs, extended hunting seasons (ideally year-round) and increased hunting of calves. Hunting for fear may offer novel opportunities to help manage the growing human–wildlife conflicts that we experience globally.

WOLF PACK TERRITORY MARKING IN THE BIAOWIE Ç ZA PRIMEVAL FOREST (POLAND)

Summary We analysed data on territory marking with urine, scats, and ground scratching by wolves (Canis lupus) belonging to four packs in the BiaA owie C Primeval Forest, Poland. The aims were to determine: (1) seasonal variation in the marking rates, (2) signie cance of various kinds of marking in territory demarcation, and (3) relationship between spatial distribution of wolves’ marking and their use of territory. Continuous radio-tracking and subsequent snow tracking of the collared wolves were the main methods. Deposition rates of scats showed little variation in time and space, whereas rates of urine marking and ground scratching showed large seasonal and spatial variation. Wolf marking rates with urine and ground scratching were highest during the cold season (October-March) and peaked during the mating season, in January and February. Marking intensity did not grow with the number of wolves in a pack, and per capita rates of marking were highest in wolves travelling singly or in pairs. Mean marking rates per km of wolf trail were low in the core areas of territories, and increased

Genetic diversity and relatedness within packs in an intensely hunted population of wolvesCanis lupus

A population of grey wolvesCanis lupus Linnaeus, 1758 inhabiting Białowieża Primeval Forest (BPF) on the Polish-Belarussian border has recovered after near extermination in the 1970s. Currently, it is intensively hunted in the Belarussian part of BPF and protected in the Polish part. We used a combination of molecular analysis, radiotracking, and field observation to study genetic diversity of the population after natural recolonisation and the consequences of heavy hunting for the genetic composition and social structure of wolf packs. Both microsatellite and mtDNA analyses revealed high genetic diversity. For 29 individuals and 20 microsatellite loci, the mean expected heterozygosity was 0.733. Four mtDNA haplotypes were found. Three of them had earlier been described from Europe. Their geographic distribution suggests that wolves recolonising BPF immigrated mainly from the north-east, and less effectively from the east and south-east. We traced the composition of 6 packs for a total of 26 pack-years. Packs were family units (a breeding pair with offspring) with occasional adoption of unrelated adult males, which occurred more frequently in packs living in the Belarussian part of the BPF, due to heavy hunting and poaching. Breeding pairs were half-sibs or unrelated wolves. Pair-bonds in the breeding pair lasted from 1 to 4 years and usually broke by the death of one or both mates. Successors of breeding females were their daughters, while a successor of a breeding male could be either his son or an alien wolf. As is evident from Białowieża’s wolves, high genetic diversity may result from immigration of outside individuals, which are easily recruited to a heavily exploited local population.

Microhabitat selection by Eurasian lynx and its implications for species conservation

We studied microhabitat selection of the Eurasian lynxLynx lynx (Linnaeus, 1758) at 116 hunting and 88 resting sites in Białowieża Primeval Forest (Poland) to describe its characteristics and determine the importance of habitat structure for stalking prey and for security during resting. We identified lynx-used sites by radio-tracking 3 male and 3 female lynx. When hunting, the lynx did not select for any type or age class of forest. During both summer and winter, the lynx selected sites characterized by high complexity (number of structures useful for stalking: fallen logs and branches, root plates, patches of dense bushes) and low visibility. In summer, hunting sites were often located in the vicinity of small forest glades that provided good stalking opportunities for lynx and rich foraging resources for roe deer — the main prey of lynx. The habitat at kill sites was more open than at sites where the prey was cached, with higher visibility, lower density of trees and poorer undergrowth. The most important characteristic of resting sites was very low visibility that resulted mainly from using young pine or spruce thickets in the winter and dense undergrowth of oak-lime-hornbeam and ash-alder forests in the summer. The information provided by this study could have direct implications for Eurasian lynx conservation by guiding forest restructuring to better suit the species’ biological requirements.

Distance rules for minimum counts of Eurasian lynx Lynx lynx family groups under different ecological conditions

Abstract Monitoring of lynx Lynx lynx populations in Scandinavia is largely based around unreplicated minimum counts of family groups, i.e. adult females with dependent kittens. When observations cannot be separated from each other on the basis of back-tracking in the snow it is desirable to use a distance rule to separate observations of groups that are so far apart that they are unlikely to be derived from the same group. We have analysed radio-telemetry derived movement data from five study areas, corresponding to three ecologically different regions, in Scandinavia, and included data from Poland for comparison. We derive examples of two different distance rules; one is a static rule based on home-range size and length which is suitable for observations accumulated during a whole winter, and the other is a dynamic rule suitable for observations collected within 1-7 days of each other. Because of inter-study area variation in home-range size and movement there is a need to use different rules in different regions. Within Scandinavia, average maximum home-range lengths varied from 28 to 54 km, and average maximum daily distances travelled varied from eight to 16 km in the three regions. This implies that locally collected movement data are a prerequisite for application of this type of methodology.

Behavioural and spatial adaptation of the Eurasian lynx to a decline in prey availability

The distribution and abundance of food resources is a major factor influencing animal populations. I studied the effect of a roe and red deer population decline on diet composition, home range size and foraging pattern in the Eurasian lynxLynx lynx (Linnaeus, 1758) in the Białowieża Primeval Forest (BPF), eastern Poland. The population of cervids in BPF experienced a nearly two-fold reduction in size from 1991 through 2006 due to severe hunting pressure between 1991 and 1996. Comparison of published data on lynx diet during the high abundance of ungulates with new data obtained for the low abundance period showed that despite a significant decline in their availability, cervids (roe and red deer) continued to form the majority of the diet of lynx, with roe deer being most preferred in both periods. Home range sizes of lynx showed a tendency to increase with declining prey densities, as indicated by relative percentage increases in average yearly home range sizes amongst different sex/age groups. In response to lower availability of their main prey, lynx increased their daily straight-line movement distances by 44% and doubled the ranges covered in 5-day periods. This illustrated that, with declining prey abundance, the lynx increased their hunting efforts by either spending more time actively searching for prey or continuing foraging even after a successful hunt. Spatial analysis of the distribution of ungulates and lynx indicated that deer were evenly distributed throughout lynx ranges in BPF and spatial proximity of the predator to prey sites did not play an important role in the efficiency of hunting. Lynx may adapt to changing prey availability by increasing search effort, but this was not sufficient to prevent the negative influences of the prey decline on the lynx population. Prey depletion has an immediate effect on lynx spatial organization and, in consequence, on their density. This information has to be considered in prioritizing lynx conservation measures and management of ungulates.