Wolf pack rendezvous site selection in Greece is mainly affected by anthropogenic landscape features

In wolves, most offspring mortality occurs within the first 6–8 months of their life. As wolf pups pass this entire period at either the den or rendezvous sites, their selection by wolf packs may affect pup survival and recruitment. Rendezvous sites are important for pup survival as they are used during summer and early autumn, when intense human activity may increase pup mortality. Adult wolves and pups can be killed by livestock guarding dogs during summer and intentionally or accidentally during large game hunting in autumn. This study describes factors related to rendezvous site selection in order to enhance their protection and management. We studied the rendezvous site selection of 30 wolf packs in central and northern Greece between 1998 and 2010, after locating 35 sites using the simulated howling survey method and telemetry. We considered a series of environmental and anthropogenic predictors of wolf rendezvous site selection at two spatial scales. At the landscape-population scale, wolves selected rendezvous sites below 1,200 m asl, with large inter-site distance (mean, 12.9 km), and avoided partially forested or open habitats, indicating preference for covered, spaced areas with seasonally stable resources. At the home range scale, wolves selected rendezvous sites away from forest roads and villages, close to water sources, and in areas with low forest fragmentation, indicating avoidance of human presence and disturbance. In the summer of 2011, we used an ensuing resource selection model (RSF, AUC?=?0.818) to successfully locate seven new rendezvous sites outside our previous survey area, verifying the utility of prediction maps (all new sites were at areas with 0.8–1 model probability). Rendezvous prediction maps can be used to reduce field effort when monitoring wolf populations, assess livestock predation risk, design protected areas, and reduce human disturbance on reproductive wolf packs.     

Den shifting by wolves in semi-wild landscapes in the Deccan Plateau, Maharashtra, India

Reproductive success is crucial for the survival and persistence of any species. The Deccan Biogeographic Zone of India is the stronghold of a population of the Indian wolf Canis lupus pallipes . Gaining a better understanding of the den-use pattern of wolves in different areas in this zone is thus vital for their conservation and management. The wolves excavated multiple dens in our study sites and kept shifting their litters among them. Major disturbance factors around denning sites were active stone quarries, traffic, crop harvesting and livestock movement. One wolf pack used 14 dens in four breeding seasons. Discriminant function analysis indicated that den shifting by wolves was not entirely governed by disturbance levels at den sites. Increasing age of pups was one of the main factors associated with den shifting rather than the magnitude of disturbance ( χ ²=34.26, d.f.=12, P <0.001). Tolerance to disturbance around dens during the early stages of pup development was negatively correlated ( r =−0.519, P <0.05) with availability of water and age of pups ( r =−0.613, P <0.01). Excavation of multiple dens by wolves was apparently related to den shifting, which seemingly is a survival strategy of wolves in these semi-wild human-dominated landscapes in the Deccan Biogeographic Zone. Principal components analysis indicated that during the initial stages of pup development, nature of the land, den orientation and distance of the den from roads were important cues in addition to age category of pups for den shifting. The analysis also suggested that factors such as distance of the new den where pups are to be transferred, distance from water source and availability of fox Vulpes bengalensis holes for den use were also important.     

Some Aspects of the Population Ecology of Wolves, Alaska

Information on Alaskan wolf populations was obtained from examinationof bounty records, 4,150 wolf radii and ulnae, 1,262 wolf carcasses,and from observations of wolves inhabiting an area of 20,000square miles where wolves were protected. Pregnant adult female wolves averaged 6.5 fetuses; two-year-oldfemales averaged 5.3 fetuses;female pups were not sexually mature. In Alaska, wolves conceive from late February through earlyApril but most females breed in March. Multiparous females breedearlier than first breeders. Multiparous females produce anaverage of 7.3 ova and 6.5 implanted fetuses. The loss of ovafrom ovulation to implantation is significant. Multiparous femalesproduce more ova than first breeders; the difference is highlysignificant. Mortality of pups rather than the lack of initial productionof pups is believed to be the reason for the observed variationsin the proportion of pups in wolf populations. Wolf packs includemembers in all categories of sex and age during the breedingseason. Size of the pack is an indicator of abundance. Wolves in an area where they were protected increased at anaverage rate of 20–30% per year during an 11-year period.     

Predicting the Spatial Distribution of Wolf (Canis lupus) Breeding Areas in a Mountainous Region of Central Italy

Wolves (Canis lupus) in Italy represent a relict west European population. They are classified as vulnerable by IUCN, though have increased in number and expanded their range in recent decades. Here we use 17 years of monitoring data (from 1993 to 2010) collected in a mountainous region of central Italy (Arezzo, Tuscany) in an ecological niche-based model (MaxEnt) to characterize breeding sites (i.e. the areas where pups were raised) within home ranges, as detected from play-back responses. From a suite of variables related to topography, habitat and human disturbance we found that elevation and distance to protected areas were most important in explaining the locality of wolf responses. Rendezvous sites (family play-back response sites) typically occurred between 800 and 1200 m a.s.l., inside protected areas, and were usually located along mountain chains distant from human settlements and roads. In these areas human disturbance is low and the densities of ungulates are typically high. Over recent years, rendezvous sites have occurred closer to urban areas as the wolf population has continued to expand, despite the consequent human disturbance. This suggests that undisturbed landscapes may be reaching their carrying capacity for wolves. This, in turn, may lead to the potential for increased human-wolf interactions in future. Applying our model, both within and beyond the species’ current range, we identify sites both within the current range and also further afield, that the species could occupy in future. Our work underlines the importance of the present protected areas network in facilitating the recolonisation by wolves. Our projections of suitability of sites for future establishment as the population continues to expand could inform planning to minimize future wolf-human conflicts.     

Die Rückkehr der Wölfe. Das erste Jahrzehnt

The first decade: the return of the wolves Wolves returned to Saxony in the year 2000 since then they have been regularly rearing pups. Nowadays at least 60‐80 wolves are living in Germany. To face its attendant conflicts a wolf management has been installed including wolf monitoring, public relation work and damage compensation. According to the monitoring wolves feed almost completely on wild ungulates, whereas livestock does not play a major role. The wolves' natural origin from north‐eastern Poland could be proven by genetic analyses. By the use of radiotelemetry important information could be gained on the adaption of the wolves to the anthropogenic landscape.     

Dispersal Behavior and the Connectivity Between Wolf Populations in Northern Europe

ABSTRACT The isolated gray wolf (Canis lupus) population of the Scandinavian Peninsular is suffering from inbreeding depression. We studied dispersal of 35 wolves fitted with very high frequency (20) or Global Positioning System—global system for mobile (15) radiocollars in the neighboring Finnish wolf population. The growing wolf population in Finland has high numbers of dispersing individuals that could potentially disperse into the Scandinavian population. About half (53%) of the dispersing wolves moved total distances that could have reached the Scandinavian population if they had been straight-line moves, but because of the irregular pattern of movements, we detected no wolves successfully dispersing to the Scandinavian population. Dispersal to the Scandinavian population was also limited by high mortality of wolves in reindeer (Rangifer tarandus) management areas and by dispersal to Bothnian Bay at times of the year when ice was not present. We suggest that when a small wolf population is separated from source populations by distance, barriers, and human exploitation, wildlife managers could promote the population's viability by limiting harvest in the peripheral areas or by introducing wolves from the source population.     

Movements and Home Sites of Timber Wolves in Algonquin Park

Ecological studies of timber wolves (Canis lupus) in a forestedenvironment have always been difficult to undertake in the past,particularly during the summer months, because of the lack ofa suitable technique. In 1960 Pimlott devised a technique whichemployed the use of broadcast wolf howls in locating wolvesin the field. This report reviews the success of this techniquein studying the movements of two packs of wolves, and theiruse of home sites in Algonquin Park, Ontario. Wolves responded by howling a total of 476 occasions or approximately13% of the occasions that broadcast howls were given. Humanimitations were more successful than tape-recordings in inducingresponses. Wolves responded at any time of day, but dusk wasthe most favorable period. They also responded more frequentlyin July and August than in May and June. Two types of home sites were found: the den site, occupied duringthe early life of the pups, and the rendezvous site, a placeoccupied by wolves during later development of pups. All ofhe home sites were adjacent to some immediate source of water.The movement of wolves appeared also to be concentrated alongthe water courses. The locations of the home sites and the evidence obtained fromhowling responses, tracks, and scats suggested that the summerrange comprised a minimum area of eight square miles. The samerange was utilized by a pack in 1961 and 1963.     

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.     

From overlooking to concealed: predator avoidance in an apex carnivore

Many prey species select bed sites that reduce the risk of being caught off guard. We investigated bed sites used by an apex predator (gray wolf, Canis lupus) before and after individuals were approached by humans (N?=?48 trials). On 9 out of 10?days, the unprovoked wolves rested at sites high in the terrain with a good overview (overlooking sites). After being approached, they resettled on more concealed sites lower in the terrain. Solitary yearlings used less overlooking sites than adults both before and after disturbance. The study provides experimental evidence that wolves’ behavioural response to approaching humans is analogous to predator avoidance in prey species.     

Wolf Use of Summer Territory in Northeastern Minnesota

ABSTRACT Movements of wolves (Canis lupus) during summer 2003 and 2004 in the Superior National Forest were based around homesites but included extensive use of territories. Away from homesites, wolves used different areas daily, exhibiting rotational use. Mean daily range overlap was 22% (SE = 0.02) and that of breeding wolves was significantly greater than for nonbreeders ( = 25% and 16%, respectively). Rotational use may improve hunting success. Managers seeking to remove entire packs must maintain control long enough to ensure that all pack members are targeted.     

Effectiveness of Lethal,Directed Wolf-Depredation Control in Minnesota

Abstract: Wolf (Canis lupus) depredations on livestock in Minnesota, USA, are an economic problem for many livestock producers, and depredating wolves are lethally controlled. We sought to determine the effectiveness of lethal control through the analysis of data from 923 government-verified wolf depredations from 1979 to 1998. We analyzed the data by 1) assessing the correlations between the number of wolves killed in response to depredations with number of depredations the following year at state and local levels, and 2) the time to the next depredation. No analysis indicated that trapping wolves substantially reduced the following year's depredations at state or local levels. However, more specific analyses indicated that in certain situations, killing wolves was more effective than no action (i.e., not trapping). For example, trapping and killing adult males decreased the re-depredation risk. At sheep farms, killing wolves was generally effective. Attempting to trap, regardless of the results, seemed more effective at reducing depredations than not trapping, suggesting that mere human activity near depredation sites might deter future depredations. (JOURNAL OF WILDLIFE MANAGEMENT 72(3):778–784; 2008)     

What Drives Wolves: Fear or Hunger? Humans,Diet, Climate and Wolf Activity Patterns

Activity patterns of animals depend on environmental and intrinsic factors. Studies undertaken across the current wolf ( Canis lupus ) range suggested a number of variables that may be correlated with activity patterns of wolves. These factors vary locally and there has been no attempt so far at defining those that ubiquitously impact wolf behaviour. I compared 11 studies (from Alaska to Israel) to assess the influence of (1) public road density, (2) human population density, (3) human-caused mortality, (4) proportion of domestic animals in wolf diet, (5) proportion of forest, (6) latitude and (7) mean annual temperature on nocturnal wolf activity and movements. Nocturnal activity was mainly correlated to the proportion of domestic animals in the diet and the density of public roads, whereas nocturnal movements were mainly correlated to latitude. The importance of latitude indicates that sun periodicity might represent an important signal (`Zeitgeber') for circadian rhythms in wolves. Environmental constraints such as high temperatures during the day and a higher hunting success in crepuscular periods probably limit the ability of wolves to avoid humans by nocturnal behaviour. I therefore suggest that in regions where wolves hunt wild prey, they experience a trade-off between predation risk by humans and increased hunting success during twilight hours.     

Conflict Misleads Large Carnivore Management and Conservation: Brown Bears and Wolves in Spain

Large carnivores inhabiting human-dominated landscapes often interact with people and their properties, leading to conflict scenarios that can mislead carnivore management and, ultimately, jeopardize conservation. In northwest Spain, brown bears Ursus arctos are strictly protected, whereas sympatric wolves Canis lupus are subject to lethal control. We explored ecological, economic and societal components of conflict scenarios involving large carnivores and damages to human properties. We analyzed the relation between complaints of depredations by bears and wolves on beehives and livestock, respectively, and bear and wolf abundance, livestock heads, number of culled wolves, amount of paid compensations, and media coverage. We also evaluated the efficiency of wolf culling to reduce depredations on livestock. Bear damages to beehives correlated positively to the number of female bears with cubs of the year. Complaints of wolf predation on livestock were unrelated to livestock numbers; instead, they correlated positively to the number of wild ungulates harvested during the previous season, the number of wolf packs, and to wolves culled during the previous season. Compensations for wolf complaints were fivefold higher than for bears, but media coverage of wolf damages was thirtyfold higher. Media coverage of wolf damages was unrelated to the actual costs of wolf damages, but the amount of news correlated positively to wolf culling. However, wolf culling was followed by an increase in compensated damages. Our results show that culling of the wolf population failed in its goal of reducing damages, and suggest that management decisions are at least partly mediated by press coverage. We suggest that our results provide insight to similar scenarios, where several species of large carnivores share the landscape with humans, and management may be reactive to perceived conflicts.     

Biomass Flow and Scavengers Use of Carcasses after Re-Colonization of an Apex Predator

Background

Reestablishment of apex predators influences the availability and distribution of biomass for scavengers and can therefore be an important agent for structuring species communities. We studied how the re-colonization of the Scandinavian Peninsula by wolves (Canis lupus) affected the amount and temporal variation in use of moose (Alces alces) carcasses.

Methodology/Principal Findings

We compared the availability of biomass from remains at wolf kills with those killed by hunters, vehicle collisions and natural death. Movement-triggered cameras monitored patterns of use on wolf kills and remains from hunter harvest by scavengers (n = 15 276) in relation to time of year, available carcass biomass, time since the death of the moose and presence of wolves. Remains from hunter harvest were the largest food source for scavengers both within wolf territories (57%) and in areas without wolves (81%). The total annual biomass available were similar in areas with (25 648 kg) and without (24 289 kg) wolves. Presence of wolves lowered the peak biomass available from hunter harvest in October (20%) and increased biomass available during December to August (38–324% per month). The probability of scavengers being present decreased faster with time at remains from hunter harvest compared to wolf kills and both the probability of being present and the number of visits by scavengers to wolf kills increased as the amount of biomass available on the carcass increased.

Conclusions/Significance

Wolves reduced the seasonal variation of biomass from moose carcasses and most important increased it during spring. Scavengers also visited wolf kills most frequently during spring when most scavenging species have young, which may lead to an increase in survival and/or reproductive success of scavengers within wolf territories. This applies both for abundant scavenging species that were the most frequent visitors at wolf kills and threatened scavengers with lower visit frequency.     

Testing Global Positioning System Telemetry to Study Wolf Predation on Deer Fawns

ABSTRACT We conducted a pilot study to test the usefulness of Global Positioning System (GPS) collars for investigating wolf (Canis lupus) predation on white-tailed deer (Odocoileus virginianus) fawns. Using GPS collars with short location-attempt intervals on 5 wolves and 5 deer during summers 2002–2004 in northeastern Minnesota, USA, demonstrated how this approach could provide new insights into wolf hunting behavior of fawns. For example, a wolf traveled ≥1.5–3.0 km and spent 20–22 hours in the immediate vicinity of known fawn kill sites and ≥0.7 km and 8.3 hours at scavenging sites. Wolf travel paths indicated that wolves intentionally traveled into deer summer ranges, traveled ≥0.7–4.2 km in such ranges, and spent <1–22 hours per visit. Each pair of 3 GPS-collared wolf pack members were located together for ≤6% of potential locations. From GPS collar data, we estimated that each deer summer range in a pack territory containing 5 wolves ≥1 year old and hunting individually would be visited by a wolf on average every 3–5 days. This approach holds great potential for investigating summer hunting behavior of wolves in areas where direct observation is impractical or impossible.     

Conservation of wildlife populations: factoring in incremental disturbance

Progressive anthropogenic disturbance can alter ecosystem organization potentially causing shifts from one stable state to another. This potential for ecosystem shifts must be considered when establishing targets and objectives for conservation. We ask whether a predator–prey system response to incremental anthropogenic disturbance might shift along a disturbance gradient and, if it does, whether any disturbance thresholds are evident for this system. Development of linear corridors in forested areas increases wolf predation effectiveness, while high density of development provides a safe‐haven for their prey. If wolves limit moose population growth, then wolves and moose should respond inversely to land cover disturbance. Using general linear model analysis, we test how the rate of change in moose (Alces alces) density and wolf (Canis lupus) harvest density are influenced by the rate of change in land cover and proportion of land cover disturbed within a 300,000 km² area in the boreal forest of Alberta, Canada. Using logistic regression, we test how the direction of change in moose density is influenced by measures of land cover change. In response to incremental land cover disturbance, moose declines occurred where <43% of land cover was disturbed; in such landscapes, there were high rates of increase in linear disturbance and wolf density increased. By contrast, moose increases occurred where >43% of land cover was disturbed and wolf density declined. Wolves and moose appeared to respond inversely to incremental disturbance with the balance between moose decline and wolf increase shifting at about 43% of land cover disturbed. Conservation decisions require quantification of disturbance rates and their relationships to predator–prey systems because ecosystem responses to anthropogenic disturbance shift across disturbance gradients.     

Activity patterns of gray wolves housed in small vs. large enclosures

Free-ranging gray wolves (Canis lupus) generally inhabit large home ranges, yet they are housed in a variety of restricted spaces when in captivity. There is continual debate as to whether space restrictions alter a wolf's behavior. The purpose of these studies was to remotely measure and then compare the amount and frequency of activity of gray wolves housed in small, artificial enclosures vs. large, more natural enclosures. Test animals comprised three adult wolves housed in kennels and three and four wolves housed in separate natural enclosures. Kenneled wolves had 2.8 m² of surface area per wolf, and wolves in natural enclosures had 466.6 m² (South Pack) and 349.9 m² (North Pack) per wolf. Wolves were fitted with radiotelemetry collars containing activity sensors. Activity data were recorded every 20 min for 57 continuous hr. The amount of activity for each wolf was calculated using areas under the curve (AUCs), and the frequency of activity was analyzed by spectral analysis. There was no difference (P ≥ 0.22) in AUCs between kenneled wolves (1.399 ± 0.214 x 10⁵ radians) and South Pack wolves (1.564 ± 0.139 X 10⁵ radians) or North Pack wolves (1.617 ± 0.192 x 10⁵ radians). All three groups had similar peak spectral values at frequencies that were close to daily cycles (i.e., ω = 0.12–0.17 cycles per unit time). Peaks in coherence near the dominant spectral frequency were most significant between the natural enclosures and the least significant between the kenneled wolves and the South Pack wolves. Based on these criteria of activity and under these circumstances, enclosure size appeared to have no effect on wolf activity. However, small sample sizes and variation in the data do not make these results definitive. © 1996 Wiley-Liss, Inc.     

Meta-Analysis of Relationships between Human Offtake,Total Mortality and Population Dynamics of Gray Wolves (Canis lupus)

Following the growth and geographic expansion of wolf (Canis lupus) populations reintroduced to Yellowstone National Park and central Idaho in 1995–1996, Rocky Mountain wolves were removed from the endangered species list in May 2009. Idaho and Montana immediately established hunting seasons with quotas equaling 20% of the regional wolf population. Combining hunting with predator control, 37.1% of Montana and Idaho wolves were killed in the year of delisting. Hunting and predator control are well-established methods to broaden societal acceptance of large carnivores, but it is unprecedented for a species to move so rapidly from protection under the Endangered Species Act to heavy direct harvest, and it is important to use all available data to assess the likely consequences of these changes in policy. For wolves, it is widely argued that human offtake has little effect on total mortality rates, so that a harvest of 28–50% per year can be sustained. Using previously published data from 21 North American wolf populations, we related total annual mortality and population growth to annual human offtake. Contrary to current conventional wisdom, there was a strong association between human offtake and total mortality rates across North American wolf populations. Human offtake was associated with a strongly additive or super-additive increase in total mortality. Population growth declined as human offtake increased, even at low rates of offtake. Finally, wolf populations declined with harvests substantially lower than the thresholds identified in current state and federal policies. These results should help to inform management of Rocky Mountain wolves.     

Gray wolf density and its association with weights and hematology of pups from 1970 to 1988.

We examined weights and hematologic profiles of gray wolf (Canis lupus) pups and the associated wolf density in the east-central Superior National Forest of northeastern Minnesota (USA) during 1970 to 1988. We collected weight and hematologic data from 117 pups (57 females, 60 males) during 1 September to 22 November each year. The wolf density (wolves/800 km2) trend was divided into three phases: high (72 +/- 7), 1970 to 1975; medium (44 +/- 2), 1976 to 1983; and low (27 +/- 2), 1984 to 1988. Wolf numbers declined (P = 0.0001) 39 and 63% from 1970 to 1975 to 1976 to 1983 and from 1970 to 1975 to 1984 to 1988, respectively. Weight was similar between male and female pups and did not vary as wolf density changed. Mean hemoglobin (P = 0.04), red (P = 0.0001) and white blood cells (P = 0.002), mean corpuscular volume, mean corpuscular hemoglobin concentration and mean corpuscular hemoglobin (P = 0.0001) did differ among the multi-annual phases of changing wolf density. Weight and hematologic data also were compared to values from captive wolf pups. The high, but declining wolf density was associated with macrocytic, normochromic anemia in wolf pups, whereas the lowest density coincided with a hypochromic anemia. Although hematologic values show promise for assessing wolf pup condition and wolf population status, they must be used cautiously until data are available from other populations.     

Surveying Predicted Rendezvous Sites to Monitor Gray Wolf Populations

ABSTRACT We used rendezvous site locations of wolf (Canis lupus) packs recorded during 1996–2006 to build a predictive model of gray wolf rendezvous site habitat in Idaho, USA. Variables in our best model included green leaf biomass (Normalized Difference Vegetation Index), surface roughness, and profile curvature, indicating that wolves consistently used wet meadow complexes for rendezvous sites. We then used this predictive model to stratify habitat and guide survey efforts designed to document wolf pack distribution and fecundity in 4 study areas in Idaho. We detected all 15 wolf packs (32 wolf pack-yr) and 20 out of 27 (74%) litters of pups by surveying <11% of the total study area. In addition, we were able to obtain detailed observations on wolf packs (e.g., hair and scat samples) once we located their rendezvous sites. Given an expected decrease in the ability of managers to maintain radiocollar contact with all of the wolf packs in the northern Rocky Mountains, rendezvous sites predicted by our model can be the starting point and foundation for targeted sampling and future wolf population monitoring surveys.