Reginald H. Barrett

Movement Patterns of Mountain Lions during Different Behaviors

We used radiotracking and other observations to describe nocturnal movement patterns of mountain lions ( Felis concolor ) during six different behaviors and attempted to estimate behavior rates by inference from such patterns. When hunting, mountain lions apparently stalked or sat in ambush for periods averaging 0.7 h and then moved a mean distance of 1.4 km (over 1.2 h) to another area; this pattern repeated about six times on nights when no prey was killed. When a mammal was killed, this pattern was suspended until the carcass was consumed (4–6 h for a small mammal, 2–5 days for a large mammal). When feeding on a large mammal, mountain lions minimized spoilage and loss to scavengers by dragging the kill 0–80 m to a cache site, burying the carcass under leaves and debris during the daytime, and feeding only at night. Mountain lions increased the risk of loss to scavengers by locating diurnal rest sites up to 4.2 km ( X = 400 m, SD = 787) from the carcass. Mating associations lasted 2–5 days, during which mountain lions traveled little, vocalized frequently, and apparently did not feed. Mothers of neonates hunted from dusk to midnight and then returned to the den; mothers spent increasing amounts of time at greater distances from the den during the first 8 weeks after giving birth. Dens were located in nearly impenetrable vegetation and den sites lacked feces, prey remains, or modifications of the site. On average, an adult mountain lion killed ca. 48 large and 58 small mammals/year and fed for an average of 2.9 days ( SD = 1.1) on a single large mammal. Although movement patterns differed markedly among behaviors, discriminant functions failed to accurately predict behavior from movement patterns.

Relationship between food habits and activity patterns of pine martens

Pine martens ( Martes americana ) consume a variety of food types annually but seasonal foraging is restricted to a subset of available prey. Winter foods include chickarees ( Tamiasciurus douglasii ), voles ( Microtus spp.), snowshoe hares ( Lepus americanus ), and flying squirrels ( Glaucomys sabrinus ), whereas ground-dwelling sciurids ( Spermophilus spp. and Eutamias spp.) comprise the bulk of the diet during the remainder of the year. Activity also is variable by season, with martens foraging at night during winter and by day during summer. Seasonal marten activity does not appear associated with optimal ambient temperature but instead appears synchronized with the activity of prey.

RESTING HABITAT SELECTION BY FISHERS IN CALIFORNIA

Abstract We studied the resting habitat ecology of fishers (Martes pennanti) in 2 disjunct populations in California, USA: the northwestern coastal mountains (hereafter, Coastal) and the southern Sierra Nevada (hereafter, Sierra). We described resting structures and compared features surrounding resting structures (the resting site) with those at randomly selected sites that also were centered on a large structure. We developed Resource Selection Functions (RSFs) using logistic regression to model selection of resting sites within home ranges, and we evaluated alternative models using an information–theoretic approach. Forty-five fishers were radiomarked, resulting in 599 resting locations. Standing trees (live and dead) were the most common resting structures, with California black oak (Quercus kelloggii) and Douglas-fir (Psuedotsuga menziesii) the most frequent species in the Sierra and Coastal study areas, respectively. Resting structures were among the largest diameter trees available, averaging 117.3 ± 45.2 (mean ± SE) cm for live conifers, 119.8 ± 45.3 for conifer snags, and 69.0 ± 24.7 for hardwoods. Females used cavity structures more often than males, while males used platform structures significantly more than females. The diversity of types and sizes of rest structures used by males suggested that males were less selective than females. In the Sierra study area, where surface water was less common, we found almost twice as many resting sites as random points within 100 m of water. Multivariate regression analysis resulted in the selection of RSFs for 4 subsets of the data: all individuals, Sierra only, Coastal only, and females only. The top model for the combined analysis indicated that fishers in California select sites for resting with a combination of dense canopies, large maximum tree sizes, and steep slopes. In the Sierra study area, the presence of nearby water and the contribution of hardwoods were more important model parameters than in the Coastal area, where the presence of large conifer snags was an important predictor. Based on our results, managers can maintain resting habitat for fishers by favoring the retention of large trees and the recruitment of trees that achieve the largest sizes. Maintaining dense canopy in the vicinity of large trees, especially if structural diversity is increased, will improve the attractiveness of these large trees to fishers.

Beaver habitat use and impact in Truckee River Basin, California

Stepwise logistic regression was used to identify factors important for habitat use by beavers (Castor canadensis) on streams. Increasing stream width and depth and decreasing gradient had the strongest positive effects on habitat use; food availability variables added little explanatory power. Some abandoned colony sites appeared to have been located on physically unsuitable habitat, whereas others appeared to be physically suitable sites abandoned due to resource depletion. The fact that few unused or uncolonized reaches were misclassified as suitable habitat suggests that suitable habitat has been saturated. Impact of beaver on woody plants was assessed for 8 forage species. Local extinction of quaking aspen (Populus tremuloides) and black cottonwood (P. trichocarpa) occurred on 4-5% of stream reaches. Willow (Salix spp.) showed good vigor despite heavy use in most reaches. J. WILDL. MANAGE. 51(4):794-799 Multivariate wildlife-habitat relationships models are often used to identify actually or potentially suitable habitat for various species, or to identify those factors that are important in habitat selection (Shugart 1981). Retzer (1955), Slough and Sadlier (1977), and Howard and Larson (1985) have used quantitative techniques to relate beaver occurrence, persistence, and density to various physical and vegetative characteristics. Wildlife managers have long been concerned with the loss of aesthetic value and impacts on stream channels due to destruction of riparian vegetation by beaver (Bump 1941, Munther 1981). Hall (1960) reported that beaver will deplete aspen in the immediate vicinity of a colony. However, there has been little quantitative documentation of the role of these animals in the loss of riparian vegetation (Kindschy 1985). Our objectives were to: (1) develop a model to identify the physical and vegetative characteristics of habitat colonized by beavers, and validate the model on a set of stream reaches not used in model development; (2) use the model results to suggest causes for colony abandonment, and evaluate whether beaver have saturated suitable habitat during the 40 years since introduction; and (3) describe the impact of beavers on woody vegetation. This research was supported by the Calif. Dep. Fish and Game and the Calif. Agric. Exp. Stn. Proj. 4326-MS. J. S. Slaymaker assisted in most of the fieldwork. M. L. Morrison, R. A. Lancia, S. H. Jenkins, and W. M. Block provided helpful criticisms of the manuscript. STUDY AREA The Truckee River Basin lies within Sierra, Nevada, Placer, and El Dorado counties, California, and Washoe County, Nevada. Our study covered the Truckee River and its tributaries from the confluence with Deer Creek downstream to Verdi, Nevada. This encompassed an area of approximately 600 km2, with 153 km of streams ranging from 1,485 to 2,750 m in elevation. Beavers were introduced into the area during 1938-46 and have since established colonies throughout the basin (P. Beier and R. H. Barrett, unpubl. data). The dominant vegetation of the area is mixed conifer forest with an overstory of white fir (Abies concolor); Jeffrey (Pinus jeffreyi), ponderosa (P. ponderosa), Washoe (P. washoensis), and lodgepole (P. contorta) pine; and a shrub component including greenleaf (Arctostaphylos patula) and whiteleaf (A. viscida) manzanita, snowbrush (Ceanothus velutinus) and squawcarpet ceanothus (C. prostratus), pale serviceberry (Amelanchier pallida), rose (Rosa spp.), and Sierra gooseberry (Ribes roezlii). The mixed conifer forest is replaced in higher elevations by a forest dominated by Shasta red fir (Abies magnifica), western white pine (P. monticola), and lodgepole pine, with squawcarpet as a dominant shrub; and in lower elevations by open stands of Jeffrey pine and an understory including big sagebrush (Artemisia tridentata), antelope bitterbrush (Purshia tridentata), and herbaceous plants. Stream banks were characterized by deciduous riparian vegetation consisting of aspen, cottonwood, willow, mountain alder (Alnus in-

Marten Habitat Preferences in the Northern Sierra Nevada

Marten were studied in the 40-km2 Sagehen Creek Basin in Tahoe National Forest, Nevada County, California. Elevations range from 1,880 to 2,620 m. Summers are short and dry with great diurnal temperature variations; winters are long and nocturnally cold, but with midday temperatures often above 0 C. Most of the 91 cm of annual precipitation falls as snow. Average winter snow pack is 112 cm at 1,950 m elevation and may be substantially deeper at higher elevations. Xeric areas are dominated by Jeffrey pine (Pinus jeffreyi) and mixed Jeffrey pine-white fir (Abies concolor) (Jeffrey pine associations). Mixtures of lodgepole pine (P. contorta) and white fir (mixed conifer associations) dominate below 2,050 m elevation (lower basin). Above 2,050 m elevation (upper basin), red fir (A. magifica) dominates, with admixtures of mountain hemlock (Tsuga mertensiana) and western white pine (P. monticola) (red fir associations). Moist areas, comprising about 5% of the drainage, are dominated by lodgepole pine and a dense cover of sedges, forbs, and willow shrubs (Salix spp.) (riparian lodgepole associations). Large brushfields resulting from wildfire cover one-third of the study area.

Cameras, coyotes, and the assumption of equal detectability

Abstract Remote cameras are an increasingly important tool in management and wildlife studies. However, we often do not know if they provide an unbiased sample of populations. Using a marked, radiocollared population of coyotes (Canis latrans) of known social status, we evaluated the influence of temporal (daily and seasonal) and spatial (distance between units, habitat, and proximity to human structures) factors on vulnerability to photo-captures. During 8 unbaited camera sessions of 6 weeks each, we obtained 158 coyote photographs at a photo-capture success rate of 1.6%. We were able to identify not only marked individuals, but also a number of uncollared adults through variation in their pelage. Photo-capture of adults peaked 2 weeks after we established camera stations. Annual success for photographing adult coyotes was greatest during March and April, which corresponded with the dispersal season. The majority of photo-captures occurred at night, and adult photo-captures peaked around midnight, with smaller peaks at dawn and dusk. Rather than reflecting a circadian activity pattern, nighttime captures seemed to reflect when adult coyotes were most vulnerable to photo-capture. Characteristics of camera locations, such as amount of human activity, being on roads versus trails, and habitat type, also influenced the number of photo-captures. We conclude that remote cameras do not always provide an unbiased sample of populations and that animal behavior is important to consider when using these systems. Researchers using camera techniques need to carefully consider when, where, and how cameras are placed to reduce this bias.

Home Range Characteristics of Fishers in California

Abstract The fisher (Martes pennanti) is a forest mustelid that historically occurred in California from the mixed conifer forests of the north coast, east to the southern Cascades, and south throughout the Sierra Nevada. Today fishers in California occur only in 2 disjunct populations in the northwestern mountains and the southern Sierra Nevada. We studied the ecology of fishers in both populations (the north coast [Coastal] and southern Sierra Nevada [Sierra]) to characterize the size and composition of their home ranges, and to compare features between locations. Twenty-one (9 Coastal, 12 Sierra) of 46 radiocollared fishers were relocated frequently enough (>20 times) to estimate home ranges. The home ranges of males (X̄ = 3,934.5 ha) were significantly greater than those of females (980.5 ha), and the home ranges of females were significantly greater in the Coastal than in the Sierra area. The smaller home ranges in the Sierra were probably due to productive habitats rich in black oak (Quercus kelloggii). Midseral Douglas-fir (Pseudotsuga menziesii) and white fir (Abies concolor) types composed the greatest proportion (42.8%) of home ranges in the Coastal study area. The greatest proportion of home ranges in the Sierra study area were in the intermediate tree size class (60.7%), had dense canopy closure (66.3%), and were in the Sierran Mixed Conifer type (40.1%). These measures provide guidelines for managers who wish to influence landscape features to resemble occupied fisher habitat. The recovery of fishers in the Pacific States, however, will also require the consideration of microhabitat elements and characteristics of landscapes that might affect metapopulation dynamics.

Relative importance of lizards and mammals as hosts for ixodid ticks in northern California

Lizards and mammals were trapped and examined for ticks from August 1992 to June 1993 in two habitat types, chaparral and woodland-grass, in northern California. Five tick species were collected from mammals (Dermacentor occidentalis, Haemaphysalis leporispalustris, Ixodes pacificus, I. spinipalpis, I. woodi), but only I. pacificus was found on lizards. Dermacentor occidentalis, I. pacificus, and I. woodi occurred in both habitats, whereas H. leporispalustris and I. spinipalpis were found only on animals trapped in chaparral. The tick species most commonly encountered on mammals was D. occidentalis in chaparral and I. pacificus in woodland-grass. Peak infestation of mammals occurred in spring for I. pacificus immatures and H. leporispalustris, summer for D. occidentalis immatures, fall through spring for I. woodi immatures, and fall through winter for I. spinipalpis. The primary aim of the study was to quantify the relative importance of the western fence lizard (Sceloporus occidentalis), which is reservoir-incompetent for Borrelia burgdorferi sensu lato (s.l.), and mammalian B.burgdorferi s.l.-reservoirs as hosts for the immature stages of I. pacificus in spring. The estimated relative utilization by I. pacificus of the western fence lizard versus mammals was 88% for larvae and 99% for nymphs in chaparral in May. When tick infestation data were corrected for a two-fold lower efficiency of field examinations for rodents than for lizards, the western fence lizard still accounted for 78% of larval and 98% of nymphal feedings. In woodland-grass, 46% of 100 I. pacificus larvae and 100% of 52 nymphs recovered from mammals or western fence lizards during May-June were collected from the lizards. However, this may represent an underestimate of the importance of the western fence lizard as a larval host in this habitat because inclement weather during the late May sampling period doubtless resulted in significantly decreased lizard activity. In conclusion, the western fence lizard was more heavily utilized by I. pacificus immatures, especially nymphs, than were rodents.

Diet of Fishers (Martes pennanti) at the Southernmost Extent of Their Range

Fishers ( Martes pennanti ) in the mountains of Californias Sierra Nevada occur at the southwestern margin of their distribution and inhabit different forest types with different potential prey than elsewhere in their range. Two typical fisher prey, the snowshoe hare ( Lepus americanus ) and the porcupine ( Erethizon dorsatum ), are absent from our Sierra Nevada study area. We characterized the diet of fishers in the southern Sierra Nevada by analyzing the content of 201 feces (44 males: 157 females) collected either from trapped animals or from the rest sites of radio-collared animals. Mammals were the most frequent food item; however, unlike previous reports, reptiles (20.4% of feces) and insects (55.7%) were major components of the diet. We also sampled 24 feces for the presence of spores of hypogeous fungi (false truffles) and found that 91.7% had spores representing at least six fungal species. Diversity of the diet was indicated by the fact that remains of no single family of animal or plant group were found in >22% of feces. The fisher is reputed to be a habitat specialist in the late-seral mixed conifer-deciduous forests of the western United States. Perhaps it is for this reason that our data depict the species as a dietary generalist, for whom it may be necessary to forage on many of the animal, plant, and fungal species that occur in and near mature coniferous habitat.

Coyote depredation management: current methods and research needs

Abstract This paper examines the severity of livestock depredation by coyotes (Canis latrans), reviews evidence implicating breeding (or “alpha”) coyotes in the majority of incidents, evaluates currently used depredation control techniques, and suggests directions for future research. Nonlethal control ranges from varied animal husbandry practices to coyote behavioral modification or sterilization. These methods show significant promise but have not been proven effective in controlled experiments. Therefore, many livestock producers rely on lethal control, and most employ nonselective strategies aimed at local population reduction. Sometimes this approach is effective; other times it is not. This strategy can fail because the alpha coyotes, most likely to kill livestock, are the most resistant to nonselective removal techniques. An alternative is selective lethal control. Livestock Protection Collars (LPCs) and coyote calling are the primary selective lethal approaches. However, LPCs do not have support from the general public due to the toxicant used, and the factors affecting the selectivity of coyote calling have not been studied. The greatest impediments to effective coyote depredation management currently are a scarcity of selective control methods, our lack of understanding of the details of coyote behavioral ecology relative to livestock depredation and wild prey abundance, the absence of solid research examining the effectiveness of different control techniques in a variety of habitats and at multiple predation intensities, and the dearth of rigorous controlled experiments analyzing the operational efficacy of selective removal versus population reduction.