Mustela Frenata Research Articles

North American weasels: resource utilization and distribution

A livetrapping program, augmented by enclosure experiments, was undertaken to study resource utilization by ermine (Mustela erminea) and long-tailed weasels (M. frenata) in southern Ontario. Data on food habits, habitat preferences, foraging strategies, and competitive interactions were collected. Based on this information, a theory was formulated to explain the distribution or North American weasels. Ermine fed primarily on meadow voles (Microtus pennsylvanicus) and had body diameters closely approximating those of meadow voles, enabling them to readily exploit these items in subnivean and subterranean environments. Long-tailed weasels were larger and their feeding habits were more general. Dietary overlap between the two species in areas of sympatry was 57.5%. Regarding habitat preferences, ermine selected successional communities, whereas long-tailed weasels showed no preferences. Overlap in areas of sympatry was 76.9%.Long-tailed weasels appear to be limited in their northward distribution by snow cover which restricts the size of foraging spaces, thereby conferring an advantage to the smaller weasels. Conversely, the southward distributions of ermine and least weasels (M. nivalis) appear to be limited by interference interactions with long-tailed weasels. Where ermine and least weasels are sympatric, size differences and general distributions suggest that they hunt different prey in different habitats.

Interaction between a Long-tailed Weasel and a Snowy Owl

Interaction between a Long-tailed Weasel and a Snowy Owl

Nowy sposób zabijania przez Mustela frenata

Techniques of killing 25 Richardson's ground squirrels, Citellus richardsoni, by an adult male long-tailed weasel, Mustela frenata, was studied in a large cage.

A New Species of Weasel (Mustela) from the Highlands of Colombia, with Comments on the Evolution and Distribution of South American Weasels

A new species of Mustela , subgenus Grammogale , is described. It is characterized by dark, uniform dorsal coloration, reduced anterior premolars, and a wide mesopterygoid fossa. a range extension is recorded for Mustela africana , and an overall evolutionary scheme for the three Neotropical species of Mustela is proposed.

Influences of Light on Activity and Phasing of Carnivores

Influences of light on the locomotor activity and phasing of 42 carnivores from 16 species were studied on four light regimes employing natural or artificial twilights: (1) outdoor light; (2) indoor, 24-h artificial light cycles with unvarying day and night illuminance and stepwise illuminance changes every 30 min during activity; and (3) indoor 3- or 4-h cycles. Responses to such tests may be the best available behavioral guide for assessing the overall state of adaptation of the visual system. Genets, kinkajous, and ringtails were strongly nocturnal. The behavior of kit foxes, long-tailed weasels, and red foxes suggests visual systems best adapted for dim light but also suitable for daylight. The arctic fox, gray fox, and striped skunk appear to be adapted for both day and night vision. Behavior of a juvenile coyote suggests optimal vision in twilights and moderate daylight, while that of a juvenile red wolf suggests better vision in moderate daylight than dim light. Animals that appear to be adapted best for daylight vision included mongooses, coatis, tayras, and a grison, but the latter three also appear to be well suited for dim-light vision. The coyote, gray foxes, long-tailed weasels, two of the three mongooses, and the red wolf were markedly or completely inhibited in darkness; those uninhibited or only partially inhibited included coatis, genets, kinkajous, kit foxes, ringtails, and a striped skunk. Large differences in individual responses to illuminance alternations and 3- or 4-h light cycles are probably characteristic of species with great versatility of vision. But the highly consistent responses of some individuals in some tests show that even animals with highly versatile vision may respond in stereotyped ways to changes in ambient illuminance. The activity distributions of certain individuals were sometimes influenced by time of feeding, while the phasing of one long-tailed weasel depended entirely on feeding time. About one-third of the animals "warmed up" to maximum speed after rest periods. Comparisons of the outdoor and indoor results suggest that the artificial, indoor 24-h light cycle with simulated twilights is a good substitute for the natural-light regime.

Seasonal and Altitudinal Variations in Populations of Small Mammals on Rattlesnake Mountain, Washington

Small mammals were live-trapped for 2 years at four elevations in shrub-steppe vegetation of S-central Washington to determine seasonal and altitudinal changes in populations. Species trapped included: Perognathus parvus, Peromyscus maniculatus, Onychromys leucogaster, Lagurus curtatus, Spermophilus townsendii; Neotoma cinerea and Mustela frenata. Perognathus parvus was the most numerous, and widespread species, reaching peak densities in the Artemisia/Poa association at 500-ft elevation. Its density declined with increasing elevation. Perognathus was most numerous on a site with a high frequency of seed-producing annuals, and less numerous in perennial grasslands or where soil temperatures below 40 F were prolonged in the spring. Peromyscus maniculatus were most numerous in the Artemisia/Agropyron association above 2000 ft. Peromyscus appeared to be limited by lack of succulent vegetation or free water at lower, more arid sites. Perognathus was most active and breeding between spring and autumn. Peromyscus favored the period between autumn and late spring. Interspecific competition was not apparent. Perognathus employed periods of torpor during the winter, and some evidence indicated that Peromyscus may have used hypothermia during the driest part of summer and midwinter. Average weights of male Perognathus increased with increasing altitude. The weight increase was not apparent in Peromyscus. (auth)

Termination of pregnancy in cats with prostaglandin F 2α. : Nachreiner, R. F. & D. N. Marple: Prostaglandins, [formula omitted](4):303, 1974. Dept. of Physiology and Pharmacology, and Dpet. of Animal and Dairy Science, School of Veterinary Medicine and School of Agriculture, Auburn University, Auburn, Alabama 36830

The ability to make a priori assessments of a species' response to fragmentation, based on its distribution in the landscape, would serve as a valuable conservation and management tool. During 1997–1999, we monitored 717 scent stations to examine seasonal use of forest patches, corridors, and crop fields by coyotes (Canis latrans), domestic cats (Felis catus), foxes (Vulpes vulpes and Urocyon cinereoargenteus), raccoons (Procyon lotor), striped skunks (Mephitis mephitis), opossums (Didelphis virginiana), and long-tailed weasels (Mustela frenata). For each species we developed landscape-based ecologically scaled landscape indices (ELSI), and we modeled species spatial distribution across three spatial scales (landscape-level, element-level, and local habitat-level). Our results suggest that these predators view landscape fragmentation at different spatial scales and demonstrate strong interspecific differences in their response to elements of the landscape. All species except coyotes and domestic cats avoided agricultural fields. In general, predator species that were more mobile (i.e. high ESLI for landscape connectivity; coyotes) were characterized by landscape- and element-based logistic models. In contrast, models including local habitat features generally were most appropriate for less mobile or more stenophagous predators (e.g. long-tailed weasels). Our analysis extends the application of the ESLI concept to species assemblages that do not appear to function as metapopulations, and it highlights the importance of examining spatial scale and species-specific responses to habitat fragmentation. We discuss the relevance of these findings for defining ecological landscapes, understanding predator–prey interactions at multiple spatial scales, and conserving predator and prey populations in fragmented landscapes.

Feeding Ecology of Four Sympatric Owls

Four species of owls, Great Horned (Bubo virginianus), Long-eared ( Asio otus), Burrowing (Speotyto cunicularia), and Barn (Tyto alba), which occur together on the short-grass prairie and farmland of north-central Colorado, were selected for a study of feeding ecology. The purpose of this study was to assess the overlap in foods of the four owls and to examine feeding mechanisms which allow them to coexist. Primary objectives were (1) to analyze and compare the food habits of each owl species considering frequency of occurrence of prey species and biomass contributed by each prey species, and (2) to describe and evaluate the primary factors involved in capture of prey by the four owl species. Few studies have been attempted in relation to the feeding of owls in this geographic area and none was a long-term study. Reed (1957) examined Barn Owl pellets from Larimer County, and Kelso (1938) and Hamilton (1941) noted Burrowing Owl foods in the Denver area. Catlett et al. (1958) studied foods of Long-eared Owls near Boulder, and Long and Kerfoot (1963) listed Great Horned Owl foods from east-central Wyoming. Most abundant of these owls is the Great Horned. This species, a permanent resident of the area, is extremely versatile in both its nesting and feeding, allowing it to utilize a wide variety of habitats. The Burrowing Owl is abundant during summer. Burrowing Owls are restricted to open lands with available nesting and roosting sites in abandoned mammal burrows, chiefly those of black-tailed prairie dogs (Cynomys ludovicianus). Arriving by mid-April, they spend about 6 months in the area before returning south in midto late October. Barn Owls are less common. Northcentral Colorado is close to the northern limits of this species' range and some may move south in winter. However, some remain through the year. Rock cliffs or ditch banks are sought for nesting and roosting by Barn Owls. Long-eared Owls are also uncommon. They appear to be nomadic-there one year and gone the next. Low, dense coniferous or deciduous trees attract them for nesting and roosting. A number of other vertebrate predators are present in this area whose diets may overlap with those of the four owl species. Other avian predators are the Golden Eagle (Aquila chrysaetos), Marsh Hawk (Circus cyaneus), Red-tailed Hawk (Buteo jamaicensis), Swainson's Hawk (B. swainsoni), Rough-legged Hawk (B. lagopus), Ferruginous Hawk (B. regalis), American Kestrel (Falco sparverius), Prairie Falcon (F. mexicanus), and Loggerhead Shrike (Lanius ludovicianus). Mammalian predators include red fox (Vulpes fulva), coyote (Canis latrans), raccoon (Procyon lotor), American badger (Taxidea taxus), striped skunk (Mephitis mephitis), and longtailed weasel (Mustela frenata). The more abundant reptilian predators are the gopher snake (Pituophus melanoleucus) and prairie rattlesnake (Crotalus viridis). The research was carried out from Decem-

Compulsory regime and control of environment in animal behaviour. II. Light level preferences of carnivores.

Abstract Thirteen individuals belonging to the carnivore species Bassariscus astittus, Genetta genetta, Mustela frenata, Mustela rixosa, Tayra barbara, and Urocyon cinereoargenteus were studied in activity-wheel enclosures in which they could control the intensity of ambient illumination in 10 steps by instrumental means. The light levels available ranged from darkness to a brightest value of 150, 300, 500, or 950 lux. The acivity indices determined at each level were: time spent running (active time) and not running (inactive time), running speed, visit lengths during activity, and number of visits. Twelve of the animals preferred the brightest or second-brightest light available. The thirteenth, a genet, had not adapted to the experimental situation after 47 days of study and spent most of the time in dim light or darkness. Active time, lengths of visits, and number of visits gave essentially the same indications of light preferences during activity, with the first two indices giving the greatest resolution. Running speed showed no noteworthy correlation with light level. Plots of the ratios of both active time and visit lengths at the brightest level to those at the second brightest appear to fall into species-specific groupings that do not correlate with body size or species affinity. There were mild to notable shifts in light level preferences from activity to inactivity. In a general way the directions of the shifts are consistent with observations of the behaviour of the animals under other conditions, i.e., light-sleeping sunbathers tended to prefer brighter light during inactivity, while sound-sleeping animals that sought protective cover during the day tended to prefer dimmer light. One of the longtailed weasels consistently adjusted the lights to a dim level or darkness when disturbed daily at feeding time. During undisturbed activity, this animal preferred the brightest light available on five different programs in which switch functions, level sequences, and illuminance values were altered, in some case to markedly different arrangements. As a working hypothesis we suggest that the preference of our carnivores for light in the range of 10 to 950 lux depends on one or more aspects of their vision - such as color, contrast, pattern, and intensity discriminations - being much improved in this range compared to that in dimmer light. On the other hand, all but one of the same animals was found to be primarily or strictly nocturnal in an independent study of activity phasing. Accordingly, it appears possible that one or more of the visual discriminations mentioned above is most sought after when the animals can alternate between conditions in which he discrimination is alternately good and poor. The animals often continued to press the levers controlling the light level after the corresponding extreme level had been attained. The relative numbers of these "false steps" on the on levers and off levers suggest that, of two means available, the animals tended to seek additional environmental modification using the means (the on levers) that yielded the preferred conditions. In addition, the animals that showed the most marked preferences for bright light also were the ones with the lowest rates of "false ons", suggesting that less motivation existed to seek change from highly preferred conditions than from less preferred ones.

Occurrence of Mustela frenata in Northern Baja California, Mexico

Occurrence of Mustela frenata in Northern Baja California, Mexico

Trichinella spiralis in Mammals at Mountain Lake, Virginia

The occurrence, epizootiology, and serology of Trichinella spiralis infection in a sylvatic environment were studied. Eleven of 85 medium-sized mammals were infected, including 4 opossums, 6 spotted skunks, and 1 longtail weasel. None of 997 rodents and insectivores examined were positive. The Card Flocculation Test was used as a simple, rapid serological test for surveying the prevalence of trichinosis in wildlife populations. The epizootiology of Trichinella spiralis (Owens, 1835) in naturally infected hosts in Iowa was reviewed by Zimmermann et al. (1962, 1963). Recently, Martin et al. (1968) studied T. spiralis infections in wild animals on two Illinois swine farms. This investigation is concerned with the occurrence, epizootiology, and serology of T. spiralis infections in mammals trapped in a sylvatic environment. MATERIALS AND METHODS During the summers 1966-68, a total of 1,094 mammals, representing 25 species, were examined for T. spiralis. Animals were trapped in the vicinity of the Mountain Lake Biological Station, Giles County, Virginia. Medium-sized mammals were live-trapped along Secondary Highways 700 and 613 from Sinking Creek to the entrance of Jefferson National Forest (1,800 to 3,800 ft above sea level). Most of the small mammals (examined in 1967 and 1968 only) were trapped by the Mammalogy Class at 24 trap sites in a 5-mile radius of the Station and from 4 major habitats: rocks, forest, field, and stream bank. Each animal was screened for infection by tissue press examination of diaphragm and intercostal muscle. Three 25to 30-g samples of ground tissue (diaphragm, intercostal, tongue, leg, and back muscle) from positive animals were digested in pepsin-hydrochloric acid, and the average number of larvae per gram of tissue determined by total counts and dilution methods. Medium-sized mammals were chloroformed and blood samples were obtained by heart puncture. The serum was separated by centrifugation, placed in sterile vials, coded, frozen, and subsequently serologically tested with the Trichinosis Card (Flocculation) Test, described by Anderson et al. (1963) and Schultz et al. (1967). The Trichinosis Card Test antigen suspension is a Melcher's acidReceived for publication 21 February 1969. * Supported in part by NSF (GB-3439) summer postdoctoral fellowship awards (1966-68) from the University of Virginia and by a Grant-in-Aid of Research from the Society of the Sigma Xi. soluble fraction of T. spiralis larvae adsorbed onto cholesterol-lecithin crystals in a suspension of charcoal particles. RESULTS AND DISCUSSION The present findings (Table I) indicate a definite focus of T. spiralis infection in Southwest Virginia. During a 3-year period, 4 of 26 opossums, 6 of 16 spotted skunks, and 1 longtail weasel were infected with T. spiralis. The prevalence rates are considerably higher than those reported by Zimmermann et al. (1962) for an 8-year period in Iowa, and undoubtedly more extensive sampling throughout Virginia would reduce these rates. Although the primary suggested method of transmission of T. spiralis in wildlife populations is scavenging of carrion, other methods such as predation, fecal, and mechanical transmission by carrion beetles and fly larvae have been recognized (Zimmermann and Hubbard, 1963). T. spiralis has been reported from the opossum, spotted skunk, and several species of Mustela (Zimmermann et al., 1962, 1963); however, the recovery of T. spiralis from the longtail weasel (Mustela frenata) is apparently the first such finding in North America. None of the 25 striped skunks examined by the tissue press technique were infected. The longtail weasel, opossum, and spotted skunk are known to feed on carrion. Garbage-fed swine, local slaughtering practices of discarding viscera in the woods, and feral dogs and cats in the vicinity of the trapping area are possible sources of transmission. A total of 997 small mammals representing 18 species were examined by the tissue press technique and were not infected with T. spiralis (Table II). Predation was thought to be of secondary importance in transmission of

Arthropod-borne-virus survey in St. Lawrence County, New York. Arbovirus reactivity in serum from amphibians, reptiles, birds, and mammals.

Summary Nine hundred and one wild-animal serum specimens (amphibian, reptilian, avian, and mammalian) from St. Lawrence County, New York, were examined by hemagglutination-inhibition and neutralization techniques for evidence of Eastern and Western encephalomyelitis, Powassan, St. Louis encephalitis, Maguari, and Cache Valley arbovirus reactivity. Group A antibody was infrequent. One Chrysemys p. picta serum had detectable EE neutralizing antibody, and a 1:20 serum dilution inhibited hemagglutination of EE antigen. Five mammalian serum specimens (one Lepus americanus, two Marmota monax, and two Vulpes fulva) demonstrated WE neutralizing antibody. Group B antibody was relatively frequent. Both serologic techniques (N and HI) detected POW antibody among 52 specimens representing nine mammalian species: one Erethizon dorsatum, one Lepus americanus, 38 Marmota monax, one Mephitis mephitis, two Mustela frenata, three Procyon lotor, two Sciurus carolinensis, one Tamias striatus, and three Tamiasciurus hudsonicus. One Rana pipiens pipiens serum showed monotypic SLE antibody by HI and N techniques. Arbovirus antibodies for groups A and B were rare among the 192 specimens of human serum, but EE, WE, POW, and SLE neutralizing antibodies were detected in four. Bunyamwera group reactivity was found only with human serum, of which 5% neutralized CV virus of the BUN group.

THE KARYOTYPE OF THE LONG TAILED WEASEL MUSTELA FRENATA NOVEBORACEISSIS EMMONS

The somatic chromosomes of the long tailed weasel, Mustela frenata from Southern Ontario were studied using tissue culture methods. The autosomes include 11 pairs of biarmed elements ranging from 2.0 to 8.15 in per cent total complement length and 9 pairs of single armed elements ranging from 3.2 to 5.00. Five of the biarmed chromosomes are metacentrics (M) ranging in arm ratio from 1.2 to 1.35 and the remaining six are submetacentrics (S) varying in arm ratio from 1.7 to 3.5. The sex chromosomes are biarmed, the X being the second smallest of the S series, whereas the Y is the smallest.

Estimating Cottontail Abundance from Livetrapping Data

Estimates of cottontail (Sylvilagus floridanus) abundance were derived from several estimating equations applied to data obtained by livetrapping a confined population of known size on the Olentangy Wildlife Experiment Station, Delaware County, Ohio, in 1961. The same methods of estimation were also applied to field data obtained in 1963 at Robert Allerton Park, Monticello, Illinois. Findings suggested that probability of capture differed among members of the populations and, perhaps, changed after capture. The multiple census methods published in 1938 by Schnabel and in 1943 by Schumacher and Eschmeyer yielded estimates well below the numbers of rabbits in the populations. A method which utilized the frequency of capture, based on techniques of maximum likelihood estimation (MLE) for the Poisson distribution, also apparently tended to underestimate rabbit abundance. A simplified equation derived for MLE for the geometric distribution produced useful estimates and is suggested for estimating rabbit numbers from data obtained by livetrapping. Intercepts of linear regression lines fitted to logarithmic plots of data on frequency of capture also appeared to yield adequate approximations of the numbers of rabbits in the zero (uncaptured) class. The mathematical bases for using these methods are subject to limitations which are discussed. The purpose of this paper is to present and compare estimates of cottontail abundance from a confined population of known size to provide a better idea of the relative accuracy of several estimating equations. Over the years several methods of estimating animal abundance from data obtained by livetrapping have been suggested. In most instances, estimating equations have been recommended on the basis of mathematical models, with no attempt made to test their accuracy by estimating known numbers of animals under field conditions. Recent papers on trap response of cottontails (Geis 1955, Huber 1962) and on problems of rabbit population studies (Eberhardt et al. 1963) suggest that a variety of factors may affect trapability of cottontails and thus bias population estimates based on capturerecapture data. The relative accuracy of several estimating equations was evaluated by comparing estimates derived from live'A contribution from Federal Aid in Wildlife Restoration Projects Ohio W-103-R and Illinois W-66-R; the U. S. Bureau of Sport Fisheries and Wildlife; the Ohio Department of Natural Resources, Division of Wildlife; the Illinois Department of Conservation; and the Illinois Natural History Survey, cooperating. Work performed in part under contract AT(451)-1350 between the Atomic Energy Commission and the General Electric Company. 87 WRIGHT, P. L. 1948. Preimplantation stages in the long-tailed weasel (Mustela frenata). Anat. Rec. 100(4):593-607. 1950. Development of the baculum of the long-tailed weasel. Proc. Soc. Expt. Biol. and Med. 75:820-822. 1953. Intergradation between Martes americana and Martes caurina in western Montana. J. Mammal. 34(1):74-86. 1963. Variations in reproductive cycles in North American mustelids. Pp. 77-97. In A. C. Enders (Editor), Delayed implantation. University of Chicago Press, Chicago, Illinois. 309pp. . 1966. Observations on the reproductive cycle of the American badger (Taxidea taxus). Pp. 27-45. In I. W. Rowlands, Editor, Comparative biology of reproduction in mammals. Symposia Zool. Soc. London, No. 15. Academic Press, London. 527pp. , AND R. RAUSCH. 1955. Reproduction in the wolverine, Gulo gulo. J. Mammal. 36(3): 346-355. Received for publication August 22, 1966. he purpose of this paper is to present d compare estimates of cottontail abunance from a confined population of known ize to provide a better id a of the relative ccuracy of several estimating equations. ver the years several methods of estimatg animal bunda ce from data obt ined ceived for publication August 22, 1966. sity of Chicago Press, Chicago, Illinois. . . bservations on the reproductive of the American badger (Taxidea taxus). -45. In I. W. Rowlands, Editor, Comi e biology of reproduction in ma mals. i g have been suggested. In ces, esti ating equations have This content downloaded from 157.55.39.207 on Thu, 20 Oct 2016 04:05:46 UTC All use subject to http://about.jstor.org/terms 88 Journal of Wildlife Management, Vol. 31, No. 1, January 1967 trapping data with the actual number of rabbits in a confined population; the same methods of estimation were applied to field data. We wish to express our appreciation to Wayne B. Nelson, Department of Mathematics, University of Illinois, for review of the mathematical concepts embodied in the method of maximum likelihood estimation, to Mrs. Helen C. Schultz and Dr. Glen C. Sanderson of the Section of Wildlife Research, Illinois Natural History Survey, for critically reading the manuscript, and especially to Edward A. Leite, Ohio Division of Wildlife, Ashley, for allowing us to cite his unpublished data.

Molineus mustelae sp. n. (Nematoda: Trichostrongylidae) from the Long-Tailed Weasel in Montana and M. chabaudi nom. n., with a Key to the Species of Molineus

Molineus mustelae sp. n. is described from seven males and seven females collected from the duodenum of the long-tailed weasel Mustela frenata in Montana. The species is differentiated from M. patens, the only species in Molineus previously reported from this weasel, and M. felineus, the species most closely resembling it. Molineus major Chabaud, Petter, and Brygoo, 1961 is amended to Molineus chabaudi (Chabaud, Petter, and Brygoo, 1961) nom. n. A key to the species of Molineus is presented. Two specimens of the long-tailed weasel Mustela frenata, collected in the vicinity of Missoula, Montana, in January and March 1964, were found to be infected with a previously undescribed species of trichostrongylid nematode. One weasel harbored 4 specimens, the other 17, in the duodenum. Three shorttailed weasels M. erminea from the same locality were not infected with this parasite. The following description is based upon seven males and seven females. Molineus mustelae sp. n.

Predation by Long-Tailed Weasels on Eggs of Blue-Winged Teal

Predation by Long-Tailed Weasels on Eggs of Blue-Winged Teal

Long-Tailed Weasel Climbing Trees

Long-Tailed Weasel Climbing Trees

Notes on Utah Weasels

Present knowledge of the natural history, ecology and distribution of weasels in Utah is based on a small but rather steadily growing list of published records and observations. The ermine, Mustela erminea muricus (Bangs), is rarely collected. Literature contains references to only seven Utah specimens. Many of the locality records for the long-tailed weasel, Mustela frenata nevadensis Hall, are from central portions of the state (Durrant: mammals of utah, Univ. Kans. Publ., 1952: 419). Little is known about this mustelid in western or other arid sections of Utah. Published reproduction data on Utah weasels also are lacking. This report contains an additional record of the ermine and new locality records and other notes on the long-tailed weasel. An adult female ermine was taken by the writer and an associate, E. A. Shippee, on September 6, 1953, at Hickerson Park on the North Fork of Sheep Creek, elevation 9300 feet, in Dagget County near the eastern end of the Uinta Mountains. This constitutes the first specimen of this species reported from these mountains and also the easternmost locality record for the state. The specimen, University of Utah collection No. …

Weasel Preys on Larval Salamander

On August 27, 1954, while on a short hike up the Wahkeena Falls Trail in the Columbia River Gorge east of Portland, Oregon, Mr. and Mrs. T. D. Kirkpatrick, my wife and myself had the opportunity of watching a weasel ( Mustela frenata ) hunting. The animal was first seen coming up the trail over which we had just walked. It nosed along checking all …

American Weasels

American Weasels