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1.
Abstract: Coyotes (Canis latrans) and Canada lynx (Lynx canadensis) are sympatric throughout much of the lynx's southern range. Researchers and managers have suggested that the presence of compacted snowmobile trails may allow coyotes to access lynx habitat from which they were previously excluded by deep, unconsolidated snow. This could then allow coyotes to more effectively compete with lynx for snowshoe hares (Lepus americanus), the lynx's primary prey. We investigated how coyotes interacted with compacted snowmobile trails by conducting carnivore track surveys and by snow tracking adult coyotes (4 M, 8 F) in areas of western Montana, USA, with both documented lynx presence and recreational snowmobile use. Coyotes remained in lynx habitat having deep snow throughout the winter months. They used compacted snowmobile trails for 7.69% of their travel distance and traveled on them for a median distance of 124 m. Coyotes used compacted forest roads (5.66% of total travel) and uncompacted forest roads (4.62% of total travel) similarly. Coyotes did not travel closer to compacted snowmobile trails than random expectation (coyote x̄ distance from compacted trails = 368 m, random expectation = 339 m) and the distance they traveled from these trails did not vary with daily, monthly, or yearly changes in snow supportiveness or depth. However, they strongly selected for naturally shallower and more supportive snow surfaces when traveling off compacted snowmobile trails. Coyotes were primarily scavengers in winter (snowshoe hare kills composed 3% of coyote feed sites) and did not forage closer to compacted snowmobile trails than random expectation. The overall influence of snowmobile trails on coyote movements and foraging success during winter appeared to be minimal on our study area. The results of this study will allow land managers to better assess the effects of snow-compacting activities on coyotes and lynx.  相似文献   

2.
In the last century, coyotes (Canis latrans) have expanded their range geographically, but have also expanded their use of habitats within currently occupied regions. Because coyotes are not morphologically adapted for travel in deep snow, we studied coyote space use patterns in a deep-snow landscape to examine behavioral adaptations enabling them to use high elevations during winter. We examined the influence of snow depth, snow penetrability, canopy cover, and habitat type, as well as the rates of prey and predator track encounters, on coyote travel distance in high-elevation terrain in northwestern Wyoming, USA. We backtracked 13 radio-collared coyotes for 265.41 km during the winters of 2006–2007 and 2007–2008, and compared habitat use and movement patterns of the actual coyotes with 259.11 km of random travel paths. Coyotes used specific habitats differently than were available on the landscape. Open woodlands were used for the majority of coyote travel distance, followed by mixed conifer, and closed-stand spruce–fir. Prey track encounters peaked in closed-stand, mature Douglas fir, followed by 50- to 150-year-old lodgepole pine stands, and 0- to 40-year-old regeneration lodgepole pine stands. Snowmobile trails had the most variation between use and availability on the landscape (12.0 % use vs. 0.6 % available). Coyotes increased use of habitats with dense canopy cover as snow penetration increased and rates of rodent and red squirrel track encounters increased. Additionally, coyotes spent more time in habitats containing more tracks of ungulates. Conversely, use of habitats with less canopy cover decreased as snow depth increased, and coyotes traveled more directly in habitats with less canopy cover and lower snow penetration, suggesting coyotes used these habitats to travel. Coyotes persisted throughout the winter and effectively used resources despite deep snow conditions in a high-elevation environment.  相似文献   

3.
Summary We studied sympatric lynx (Lynx canadensis) and coyotes (Canis latrans) to assess how morphological disadvantages to locomotion over snow affected movement patterns. Both species are of similar size and mass, but the feet of lynx are much larger, and coyotes were found to have 4.1–8.8 times the foot-load (ratio of body mass to foot area) of lynx. This resulted in greater mean sinking depths of coyote limbs, although the magnitude of the difference was less than that in foot-load. Coyotes exhibited stronger use of behavioral patterns that reduced negative effects of snow on movements. Coyotes were most abundant at low elevations where snow was shallow, whereas lynx were mostly at higher elevations. Coyotes also used areas at both elevations where snow was shallower than average, while lynx used areas where snow was deeper. further, both species used travel routes where snow was shallower than it was near the track. Coyotes traveled on harder snow and used trails more frequently, thereby tending to reduce sinking depths to those similar to lynx. The behavioral repertoire of coyotes reduced the morphological advantage of large feet possessed by lynx; however, overall sinking depths were still greater in coyotes. Snowshoe hares (Lepus americanus) were the main prey of both species, and their foot-load was less than that of either predator. Hare kills by coyotes occurred after fewer bounds than did those by lynx, and the large difference between foot-loads of both species of predators may have forced coyotes to ambush rather than chase hares, as did lynx.  相似文献   

4.
Coyote (Canis latrans) spatial and social ecology are variable, but have been little studied in high-elevation environments. In these temperate ecosystems, large ungulates are prevalent and coyote pack size may be large in order for them to scavenge and defend ungulate carcasses from conspecifics in neighboring packs. We initiated a study to understand the spatial and social ecology of coyotes on the Valles Caldera National Preserve, a high-elevation (2450–3400 m) protected area in northern New Mexico. Our objectives were to (1) describe the home range size and habitat use of coyotes in the preserve, (2) describe coyote movements within and outside of packs, and (3) to evaluate the relationship between coyote social cohesion and the amount of elk (Cervus elaphus) in the coyote diet. We acquired global positioning system and telemetry locations from 33 coyotes from August 2005 to July 2009. We classified 23 coyotes (70 % of individuals) as residents (i.e., territorial) during at least part of the study and ten coyotes (30 %) as transients. Overall mean home range size of resident packs was 10.6 ± 2.2 (SD) km2. Home range size varied between packs, but did not vary by season or year. Coyotes used dry and wet meadow habitats as expected based on availability; coyotes used riparian habitat more than expected, and forests less than expected. Social cohesion did not vary among biological seasons. Alpha coyotes were more socially cohesive with each other than with other pack members, and a transient exhibited temporal–spatial avoidance of pack members while inside the pack’s territory followed by integration into the pack. Contrary to expectations, we found no relationship between coyote social cohesion and the proportion of elk in coyote diets. We concluded that coyote space use and sociality on the preserve were relatively stable year-round despite changes in biological needs, snow depth, and utilization of variously sized prey.  相似文献   

5.
ABSTRACT We investigated seasonal patterns in resource selection of Canada lynx (Lynx canadensis) in the northern Rockies (western MT, USA) from 1998 to 2002 based on backtracking in winter (577 km; 10 M, 7 F) and radiotelemetry (630 locations; 16 M, 11 F) in summer. During winter, lynx preferentially foraged in mature, multilayer forests with Engelmann spruce (Picea engelmannii) and subalpine fir (Abies lasiocarpa) in the overstory and midstory. Forests used during winter were composed of larger diameter trees with higher horizontal cover, more abundant snowshoe hares (Lepus americanus), and deeper snow compared to random availability; multilayer, spruce-fir forests provided high horizontal cover with tree branching that touched the snow surface. During winter, lynx killed prey at sites with higher horizontal cover than that along foraging paths. Lynx were insensitive to snow depth or penetrability in determining where they killed prey. During summer, lynx broadened their resource use to select younger forests with high horizontal cover, abundant total shrubs, abundant small-diameter trees, and dense saplings, especially spruce-fir saplings. Based on multivariate logistic-regression models, resource selection occurred primarily at a fine spatial scale as was consistent with a sight-hunting predator in dense forests. However, univariate comparisons of patch-level metrics indicated that lynx selected homogenous spruce-fir patches, and avoided recent clear-cuts or other open patches. Given that lynx in Montana exhibit seasonal differences in resource selection, we encourage managers to maintain habitat mosaics. Because winter habitat may be most limiting for lynx, these mosaics should include abundant multistory, mature spruce-fir forests with high horizontal cover that are spatially well-distributed.  相似文献   

6.
Expansion of the coyote’s (Canis latrans) distribution in North America has included most urban areas. Concerns for human safety have resulted in the need to understand the spatial relationship between humans and coyotes in urban landscapes. We examined the space use of coyotes with varying degrees of urban development in the Chicago metropolitan area, IL, USA, between March 2000 and December 2002. We compared home-range size, land use, and habitat use of 41 radio-collared coyotes (5 coyotes residing in developed areas, 29 in less-developed areas, and 7 in a matrix of developed and less-developed areas). The partitioning of coyotes into groups based on their level of exposure to urban development allowed us to examine if differences in use of land types by coyotes was evident in our study area. Coyotes in developed areas had home ranges twice the size of animals in less-developed areas. Nonurban habitats were used by all coyotes in the study area, while urban land was avoided. Coyotes in developed areas had large home ranges and high amounts of urban land in their range, but preferred nonurban habitat. This required the coyotes to travel through a matrix of urban land, thus encountering human activity and possibly increasing the risk of conflict with humans. However, coyotes in developed areas avoided crepuscular times when human activity was highest, suggesting that coyotes in developed areas may reduce conflicts with humans by traveling through the matrix of urban land late at night when the risk of contact with humans is lowest. Coyotes in less-developed areas were less affected by human activity at night and likely posed less risk to humans.  相似文献   

7.
ABSTRACT

The information content of coyote (Canis latrans) vocalizations is poorly understood, but has important implications for understanding coyote behaviour. Coyotes probably use information present in barks or howls to recognize individuals, but the presence of individually-specific information has not been demonstrated. We found that coyote barks and howls contained individually specific characteristics: discriminant analysis correctly classified barks of five coyotes 69% of the time and howls of six coyotes 83% of the time. We also investigated the stability of vocalization characteristics at multiple distances from the source. Recordings were played back and re-recorded at 10 m, 500 m, and 1,000 m. Vocalization features were measured at each distance and analyzed to determine whether characteristics were stable. Most howl characteristics did not change with distance, and regardless of the distance discriminant analysis was 81% accurate at assigning howls among six individuals. Bark characteristics, however, were less stable and it is unlikely that barks could be used for individual recognition over long distances. The disparate results for the two vocalization types suggest that howls and barks serve separate functions. Howls appear optimized to convey information (i.e. data), while barks seem more suitable for attracting attention and acoustic ranging.  相似文献   

8.
The establishment of coyote (Canis latrans) populations in urban areas across North America has been accompanied by increased rates of human–coyote conflict. One factor thought to promote physical conflict between coyotes and people or pets is the presence of coyote pups near natal dens; however, this idea has not been tested, and no multivariate study of den selection within cities has occurred. Our objectives were to conduct a multivariate analysis of third- (i.e., home range) and fourth-order (i.e., den sites) habitat selection at dens and determine whether proximity to dens is associated with reports of physical conflict with coyotes. We found 120 dens by following coyote trails using snow tracking within urban green spaces that comprise presumed high-quality habitat for coyotes in Edmonton, Alberta, Canada. We used resource selection functions to assess habitat selection for dens, testing variables related to land cover and anthropogenic features at the third order, and testing microsite habitat features via paired sites at the fourth order. We defined conflict encounters from comments in a community reporting database and used general linear models to assess their spatial proximity to the nearest den and prevalence during the pup-rearing period compared to the rest of the year. Habitat selection was strongest at the fourth order, wherein coyotes selected for abundant hiding cover, steep slopes, and eastern exposure. The prevalence of physical conflict with coyotes increased during the pup-rearing period. Conflict also increased near known dens as an overall effect and when reports occurred outside of naturalized urban areas. These results suggest that coyotes in Edmonton den in green spaces near human development in microsites that minimize detection by people via steep slopes and dense vegetation. We suggest urban wildlife managers increase public safety education about recognition of coyote denning habitat and coyote defensive behaviors, especially outside of naturalized urban areas, because of the observed increase in physical conflict near dens.  相似文献   

9.
Coyotes (Canis latrans) are a highly adaptable canid species whose behavioral plasticity has allowed them to persist in a wide array of habitats throughout North America. As generalists, coyotes can alter movement patterns and change territorial strategies between residency (high site fidelity) and transiency (low site fidelity) to maximize fitness. Uncertainty remains about resident and transient coyote movement patterns and habitat use because research has reached conflicting conclusions regarding patterns of habitat use by both groups. We quantified effects of habitat on resident and transient coyote movement behavior using first passage time (FPT) analysis, which assesses recursive movement along an individual''s movement path to delineate where they exhibit area‐restricted search (ARS) behaviors relative to habitat attributes. We quantified monthly movement rates for 171 coyotes (76 residents and 53 transients) and then used estimated FPT values in generalized linear mixed models to quantify monthly habitat use for resident and transient coyotes. Transients had greater movement rates than residents across all months except January. Resident FPT values were positively correlated with agricultural land cover during fall and winter, but negatively correlated with agriculture during spring. Resident FPT values were also negatively correlated with developed habitats during May–August, deciduous land cover during June–August, and wetlands during September–January except November. FPT values of transient coyotes were positively correlated with developed areas throughout much of the year and near wetlands during July–September. Transient FPT values were negatively correlated with agriculture during all months except June and July. High FPT values (ARS behavior) of residents and transients were generally correlated with greater densities of edge habitat. Although we observed high individual variation in space use, our study found substantive differences in habitat use between residents and transients, providing further evidence that complexity and plasticity of coyote habitat use is influenced by territorial strategy.  相似文献   

10.
Prior to 1900, coyotes (Canis latrans) were restricted to the western and central regions of North America, but by the early 2000s, coyotes became ubiquitous throughout the eastern United States. Information regarding morphological and genetic structure of coyote populations in the southeastern United States is limited, and where data exist, they are rarely compared to those from other regions of North America. We assessed geographic patterns in morphology and genetics of coyotes with special consideration of coyotes in the southeastern United States. Mean body mass of coyote populations increased along a west‐to‐east gradient, with southeastern coyotes being intermediate to western and northeastern coyotes. Similarly, principal component analysis of body mass and linear body measurements suggested that southeastern coyotes were intermediate to western and northeastern coyotes in body size but exhibited shorter tails and ears from other populations. Genetic analyses indicated that southeastern coyotes represented a distinct genetic cluster that differentiated strongly from western and northeastern coyotes. We postulate that southeastern coyotes experienced lower immigration from western populations than did northeastern coyotes, and over time, genetically diverged from both western and northeastern populations. Coyotes colonizing eastern North America experienced different selective pressures than did stable populations in the core range, and we offer that the larger body size of eastern coyotes reflects an adaptation that improved dispersal capabilities of individuals in the expanding range.  相似文献   

11.
ABSTRACT Anthropogenic disturbances can promote establishment and growth of predator populations in areas where secondary prey can then become threatened. In this study, we investigated habitat selection of eastern coyotes (Canis latrans), a relatively new predator in the vicinity of an endangered population of caribou (Rangifer tarandus caribou). We hypothesized that coyotes in the boreal forest depend mainly on disturbed habitat, particularly that of anthropogenic origin, because these habitats provide increased food accessibility. Coyotes would likely take advantage of moose (Alces alces) carcasses, berries, and snowshoe hares (Lepus americanus) found in open habitats created by logging. To test these predictions, we described coyote diet and habitat selection at different spatial and temporal levels and then compared resource availability between habitats. To do so, we installed Global Positioning System radiocollars on 23 individual coyotes in the Gaspésie Peninsula, eastern Québec, Canada. Coyotes selected clear-cuts of 5–20 years and avoided mature coniferous forests both at the landscape and home-range levels. Clear-cuts of 5–20 years were found to contain a high availability of moose carcasses and berries, and vulnerability of snowshoe hares is known to increase in clear-cuts. The importance of these 3 food resources was confirmed by the characteristics of core areas used by coyotes and diet analysis. Moose remains were found at 45% of core areas and coyote diet comprised 51% moose on an annual basis. Anthropogenic disturbances in the boreal forest thus seem to benefit coyotes. Our results indicated that the relationship between coyotes and caribou likely involves spillover predation. This knowledge allows managers to consider spillover predation by coyotes as a possible threat for endangered caribou population when the predator depends mainly on habitat of anthropogenic origin and to suggest methods to alleviate it when developing management plans.  相似文献   

12.
Rates of encounters between humans and wildlife are increasing in cities around the world, especially when wildlife overlap with people in time, space and resources. Coyotes (Canis latrans) can make use of anthropogenic resources and reported rates of conflict have increased in cities across North America. This increase may be linked to individual differences in the use of human food and developed areas. We compared the relationships between coyote age, sex or health and the use of anthropogenic resources, which we defined as using developed areas over large home ranges, being active during the day, and consuming anthropogenic food. To do so, we applied GPS collars to 19 coyotes and sampled hair for stable isotope analysis. Eleven coyotes appeared to be healthy and eight were visibly infested with sarcoptic mange (Sarcoptes scabiei), a mite that causes hair loss. Diseased coyotes used more developed areas, had larger monthly home ranges, were more active during the day, and assimilated less protein than coyotes that appeared to be healthy. We speculate that anthropogenic food provides a low-quality but easily accessible food source for diseased coyotes, which in turn may increase reliance on it and other anthropogenic resources to promote encounters with people.  相似文献   

13.
Coyote (Canis latrans) removal programs often are initiated despite the potential population regulatory mechanism of parasitism with increased coyote density. We investigated the effect of intensive, short-term coyote removal on population levels of helminths in juvenile and adult coyotes from western Texas. Coyotes were killed by aerial gunning every 3 mo for 2 yr on two 5,000 ha areas, which reduced the overall coyote density of these areas by about 50%. Two other 5,000 ha areas were used as comparison sites where a limited number of coyotes were killed each season. Densities on comparison sites remained stable throughout the study at a mean +/- 1 SE of 0.14 +/- 0.01 coyotes/km2. Twelve helminth species consisting of seven nematodes (Ancylostoma caninum, Physaloptera rara, Toxascaris leonina, Dirofilaria immitis, Spirocerca lupi, Oslerus osleri, and Capillaria aerophila), three cestodes (Taenia pisiformis, Taenia multiceps, and Mesocestoides sp.), one acanthocephalan (Oncicola canis), and one trematode (Alaria marcianae) were found in 252 coyotes. Of these, A. caninum, P. rara, T. multiceps, T. pisiformis, T. leonina, and S. lupi were common species. Rank-transformed values for the mean abundances of A. caninum and T. multiceps and A. caninum, T. multiceps, and S. lupi were reduced in juvenile and adult coyotes, respectively, from the removal sites compared to respective helminth abundances in similar age class coyotes from comparison sites. Because A. caninum has been suggested as a population regulator of coyotes, a coyote removal program that results in a reduced density of coyotes and at the same time causes a reduced abundance of A. caninum, may in fact negate the regulatory effect that A. caninum has on coyote populations.  相似文献   

14.
Coyotes (Canis latrans) are reported to be less vulnerable to capture in familiar areas of territories, however, most studies do not control for trap density across the territory. We determined if accounting for trap density provided a better explanation of observed capture rates. Based on a sample of 24 captured coyotes (6 inside core areas and 18 on peripheries of occupied areas) the best fitting model describing capture location only accounted for trap density and not relative time spent in each region. Our results suggest that coyote capture rates are a function of trap density in an area and not novelty avoidance. Placing traps in core areas of territories can increase the probability of capturing individuals from specific territories to increase the effectiveness of management or research activities. © 2011 The Wildlife Society.  相似文献   

15.
Radio-collared coyotes (Canis latrans) were relocated every 15 min during continuous 24-h sampling periods. The data were used to estimate patterns of home-range use by coyotes. Utilization of the the home range was found to vary spatially and behaviourally. Spatial use was determined by relative amounts of time coyotes spent and amounts of distance they travelled within each are of their home ranges. Behavioural use was based on identification of three types of movement patterns that werew postulated to represent three general kinds of behaviour: (1) resting behaviour, (2) hunting or investigative behavour, and (3) ranging or traveling behaviour. Spatial and behavioural uses of the home range area were found to be interrelated; core areas in which animals spent most of their time were also used primarily for resting or hunting. In areas in which animals spent little time, coyotes exhibited primarily ranging behaviour. Use patterns were postulated to be the result of coyotes' selection of areas due to unique vegetal, faunal, or physiogfaphic characteristics. Temporal variatrions in home-range use were found and were postulated to result from seasonal and diel changes in coyote behaviour due to the annual reproductive cycle, the seasonal and diel cycle of temperature, possible cycles in prey behaviour.  相似文献   

16.
The health of coyotes (Canis latrans) in urban areas has not been studied. Our objectives were to assess the health of coyotes in Tucson (Arizona, USA) by determining the prevalence of antibodies to selected pathogens, estimating survival rates, and identifying sources of mortality. We drew blood from 22 coyotes to evaluate the prevalence of heartworm (Dirofilaria immitis) antigens, and antibodies to canine distemper virus (CDV), infectious canine hepatitis (ICH), canine parvovirus (CPV), and seven serovars of Leptospira interrogans. We trapped and radiocollared 19 coyotes to determine survival rates. We performed necropsies on 19 coyotes to quantify their general health, the presence of internal and external parasites, and causes of mortality. No coyotes tested positive for heartworm antigens. The prevalence of antibody to CDV, ICH, and CPV was 27, 50, and 100%, respectively. Twenty-seven percent of coyotes tested positive for one of five serovars of L. interrogans. The diseases for which coyotes in Tucson possessed antibodies appear to be enzootic in the population. The annual survival rate of coyotes was 0.72. Eleven necropsied coyotes were killed by cars, five coyotes were hit by cars, two were killed by a trapper, and the cause of death for one coyote was unknown. Coyotes in Tucson appear to be exposed to the viral, bacterial, and parasitic infections common in many coyote populations, but humans are the major source of mortality.  相似文献   

17.
Coyotes (Canis latrans) have colonized northeastern North America only within the past 10-80 yr. We examined feces of coyotes in 2000-01 at three sites in New York (USA) to survey parasites in the region. Two cestodes, nine nematodes, five protozoa, one trematode, and two arthropods were identified from 145 coyote fecal samples. Parasite component community diversity was higher (n = 16 species) in southern New York than in middle and northern sites (nine species each) and infracommunity species richness was greater in southern New York than at the other sites. These differences may reflect the variable diets of coyotes, as well as recent colonization of the region and the mixing of component communities from expanding coyote populations.  相似文献   

18.
Three genes, Mc1r, Agouti, and CBD103, interact in a type-switching process that controls much of the pigmentation variation observed in mammals. A deletion in the CBD103 gene is responsible for dominant black color in dogs, while the white-phased black bear (“spirit bear”) of British Columbia, Canada, is the lightest documented color variant caused by a mutation in Mc1r. Rare all-white animals have recently been discovered in a new northeastern population of the coyote in insular Newfoundland and Labrador, Canada. To investigate the causative gene and mutation of white coat in coyotes, we sequenced the three type-switching genes in white and dark-phased animals from Newfoundland. The only sequence variants unambiguously associated with white color were in Mc1r, and one of these variants causes the amino acid variant R306Ter, a premature stop codon also linked to coat color in Golden Retrievers and other dogs with yellow/red coats. The allele carrying R306Ter in coyotes matches that in the Golden Retriever at other variable amino acid sites and hence may have originated in these dogs. Coyotes experienced introgression with wolves and dogs as they colonized northeastern North America, and coyote/Golden Retriever interactions have been observed in Newfoundland. We speculate that natural selection, with or without a founder effect, may contribute to the observed frequency of white coyotes in Newfoundland, as it has contributed to the high frequency of white bears, and of a domestic dog-derived CBD allele in gray wolves.  相似文献   

19.
Coyotes (Canis latrans) may affect adult and neonate white-tailed deer (Odocoileus virginianus) survival and have been implicated as a contributor to the decline of deer populations. Additionally, coyote diet composition is influenced by prey availability, season, and region. Because coyote movement and diet vary by region, local data are important to understand coyote population dynamics and their impact on prey species. In southeast Minnesota, we investigated the effect of coyotes on white-tailed deer populations by documenting movement rates, distances moved, and habitats searched by coyotes during fawning and nonfawning periods. Additionally, we determined survival, cause-specific mortality, and seasonal diet composition of coyotes. From 2001 to 2003, we captured and radiocollared 30 coyotes. Per-hour rate of movement averaged 0.87 km and was greater (P = 0.046) during the fawning (1.07 km) than the nonfawning period (0.80 km); areas searched were similar (P = 0.175) between seasons. Coyote habitat use differed during both seasons; habitats were not used in proportion to their availability (P < 0.001). Croplands were used more (P < 0.001) than their proportional availability during both seasons. Use of grasslands was greater during the fawning period (P = 0.030), whereas use of cropland was greater in the nonfawning period (P < 0.001). We collected 66 fecal samples during the nonfawning period; coyote diets were primarily composed of Microtus spp. (65.2%), and consumption of deer was 9.1%. During the study, 19 coyotes died; annual survival rate range was 0.33–0.41, which was low compared with other studies. Consumption of deer was low and coyotes searched open areas (i.e., cropland) more than fawning areas with dense cover. These factors in addition to high coyote mortality suggested that coyote predation was not likely limiting white-tailed deer populations in southeast Minnesota. © 2011 The Wildlife Society.  相似文献   

20.
Activity patterns between individuals in a large herd of domestic sheep (Ovis aries) were examined to determine whether or not behavioral characteristics predisposed certain individuals to coyote (Canis latrans) predation. Coyotes killed 73 of 958 lambs and 6 of 624 ewes between 24 April and 15 August 1975. Twenty ewes and 19 lambs died from non-predatory causes. Coyote-kills accounted for 79.3% of the lamb losses. The amount of time ewes spent at various activities differed significantly by age or genotype, but the behavior of ewes whose lambs were killed was remarkably similar to that of other ewes. Single lambs were more active and were killed proportionately more often than twins. Within litters in which one of the lambs was killed, the killed sibling tended to be more active. Coyotes killed proportionately more disabled lambs and lambs from disabled ewes than healthy lambs or lambs from healthy ewes. Reduced mobility of either a lamb or a ewe increased the probability of a lamb's being on the periphery of the bed-ground and, hence, the probability that it would be noticed and attacked by a coyote. Coyote predation on domestic sheep was related more to the chance of an animal's being on the periphery of the bed-ground than to the animal's behavioral characteristics.  相似文献   

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