James G. MacCracken

Mass-diameter regressions for moose browse on the Copper River Delta, Alaska.

Regression equations were developed to predict 3 mass components of 7 browse species important to moose (Alces gigas) on the Copper River Delta in southcentral Alaska. The accuracy of model predictions was the criterion for model selection. Model accuracy was evaluated using data splitting or jackknife procedures. Annual production of twigs and leaves and available twig mass on a stem were most accurately predicted from stem basal diameter with zero intercept models, zero intercept log-linear models, or log-log models. Twig mass eaten by moose was most accurately predicted from the diameter at the point of browsing of a twig with zero intercept or full linear models. Heteroskedasticity was significant (P < 0.05) in most of the data sets and could not be significantly reduced with log transformations or use of weighted least squares models. Heteroskedasticity appeared to have a relatively minor effect on model predictions. Most of the models gave mean predictions within +/- 20% of the actual values, particularly for the most ubiquitous species that were also the most important to moose. For each species, there were few differences (P < 0.05) in model coefficients between years and among habitat types. Differences in coefficient estimates appeared to be related to differences in stem morphology that were related to both site conditions and past browsing by moose.

COYOTE FOODS IN THE BLACK HILLS, SOUTH DAKOTA

Coyotes (Canis latrans) are one of the most widely studied animals in North America. The primary reason that much effort has been directed toward understanding the coyote is its feeding patterns. Coyotes prey upon domestic animals (Murie 1951, Gipson 1974, MacCracken 1982) and game animals (Fichter et al. 1955, Beasom 1974, Salwasser 1974, MacCracken and Hansen 1982), and feed on fruit and vegetable crops (MacCracken 1982). Presumably, the primary objective of most coyote research is to gain knowledge of coyote ecology which can be used to decrease conflicts with man. Generalizations concerning coyote feeding patterns become apparent when the literature is examined. Where leporids are abundant they dominate the coyote diet (Sperry 1941, Clark 1972, MacCarcken 1981). Authors who conducted studies in areas known to have low populations of leporids reported that rodents, deer (Odocoileus spp.), livestock, or vegetation made up the bulk of coyote diets (Murie 1935, Fichter et al. 1955, Hilton 1978, Ribic 1978). Coyotes have been described as opportunistic predators for decades (Bond 1939, Todd and Keith 1983). However, no studies have been published in which the objective was to determine if coyotes are opportunistic predators. Even though studies of coyote food habits are numerous in the literature, the foods of coyotes have not been determined for many ecosystems that they in

Spatio-Temporal Constraints on Moose Habitat and Carrying Capacity in Coastal Alaska: Vegetation Succession and Climate

Abstract We used a geographic information system and a Markov chain analysis to model vegetation succession on the Copper River Delta, Alaska, relative to moose (Alces alces) habitat availability and nutritional carrying capacity. Between 1959 and 1986 vegetation predominantly shifted from pioneer to later successional communities as a result of glacial retreat and earthquake uplift. Hypothesized vectors of vegetation composition in future decades indicate a trend toward an increase in late-successional communities. A decline in glacier-related disturbance has reduced the level of retrogression that maintains early successional communities in the outwash plain. In addition, landscape heterogeneity increased significantly between 1959 and 1986, particularly in the uplifted marsh. Winter severity was highly variable among years and was correlated with a shift in the location of moose wintering areas. As winter severity increased, there was increased use of the glacial outwash plain landform and its associated plant communities. Successional modeling suggests a decline in the availability of vegetation types important to moose during severe winters with deep snow. Low willow (Salix spp.) communities are expanding in the uplifted marsh, a landform used primarily during summer and mild winters. However, tall willow communities that provide winter forage are declining and are being replaced by Sitka spruce (Picea sitchensis [Bong] Carr) forest in the glacial outwash plain. Consequently, nutritional carrying capacity of moose on the outwash plain during winter will decline by 42% during 1959–2013.

seasonal foods of blacktail jackrabbits and nuttall cottontails in southeastern Idaho.

The diets of blacktail jackrabbits (Lepus californicus) and nuttall cottontails (Sylvilagus nuttalli) were estimated by examination of fecal pellet botanical composition. The deficiencies of fecal analysis are noted, but dietary trends and relative importance of forage plants are accurate. Cluster analysis combined leporid pellets into 2 distinct groups based on botanical composition, representing feeding during spring-summer and fall-winter periods. Seven variables (plant species) accounted for significant differences (P<O.05) within and among the leporids studied in seasonal food selection. Generally, grasses and forbs were most abundant in blacktail jackrabbit and nuttall cottontail pellets during the spring-summer period, whereas shrubs were most abundant during the fall-winter period. Diet similarity was greatest between blacktail jackrabbits and nuttall cottontails during the same season. Diversity of forage consumed was greatest for both leporids during spring-summer periods. Habitat segregation minimizes competition for forage between the leporids studied. Livestock grazing appears to limit leporid population density rather than alter leporid food habits. During the period of research, authors were graduate research assistant and professor, respectively, Department of Range Science, Colorado State University, Fort Collins 80523. MacCrackens present address is P.O. Box 3145, Palmer, AK 99645. The authors thank O.D. Markham, W.J. Arthur, D.K. Halford, M.K. Johnson, G.C. Lucich, R.L. Potter, E.R. Johnson, and D. Simonson for their participation in this study. M.E. Voorhees did the microhistological work. This project was supported in part through grant DE-A507-761D-1526, MOD 006 from the U.S. Department of Energy, Idaho National Engineering Laboratory Ecology Program to Colorado State University. Manuscript received September 28, 1982. Leporids play a major role in the ecology of the Great Basin area of the western USA. They compete with livestock and other wildlife for forage, cause extensive crop damage, and are a major food source for coyotes (Clark 1972, MacCracken and Hansen 1982a) and other predators which in turn kill livestock and game animals. Leporids are primarily herbivorous, but have been reported to consume carrion (Hansen and Flinders 1969, DeCalesta 1971). When jackrabbits (Lepus spp.) become overly abundant, about every 10 years, their impact on the ecosystem is tremendous. In January 1982 such a situation existed, and it was estimated that local people killed about 64,000 jackrabbits during 6 different roundups at Mud Lake, Ida., bordering our study area. Information on food selection by jackrabbits during low and high population levels helps to determine if such controversial management procedures are justified. The foods of most species of leporids have been documented in the literature (Hansen and Flinders 1969, DeCalesta 1971). Feeding by blacktail jackrabbits (Lepus californicus) may have been the most thoroughly examined (Uresk 1978, Westoby 1980). Even though studies dealing with leporid food habits have been published, few have investigated seasonal food selection by sympatric leporids. The purpose of this paper is to present the results of a study which examined seasonal food habits of sympatric blacktail jackrabbits, and nuttall cottontail (Sylvilagus nuttalli) in southeastern Idaho when the jackrabbit population was at low levels. 256 JOURNAL OF RANGE MANAGEMENT 37(3), May 1984 This content downloaded from 40.77.167.54 on Wed, 06 Jul 2016 04:25:14 UTC All use subject to http://about.jstor.org/terms

Herbaceous Vegetation of Habitat Used by Blacktail Jackrabbits and Nuttall Cottontails in Southeastern Idaho

Abundance of blacktail jackrabbits (Lepus californicus) and nuttall cottontails (Sylvilagus nuttalli) as determined by fecal pellet accumulation was positively related to biomass of herbaceous vegetation on the Idaho National Engineering Laboratory Site. These leporids were most abundant where biomass of herbaceous vegetation was greatest, but abundance of blacktail jackrabbits and nuttall cottontails was related inversely. Blacktail jackrabbits occupied sites with a larger biomass of grasses than forbs, while nuttall cottontails occupied areas with larger forb biomass and numerous rock outcrops. Both species were most abundant on portions of the study area not grazed by livestock.

Diets of domestic sheep and other large herbivores in Southcentral Colorado.

The botanical composition of herbage consumed by domestic sheep, mule deer, domestic cattle and elk from critical big game winter ranges in southcentral Colorado was studied using the fecal analysis technique. The food habits of domestic sheep grazed during the late spring overlapped those of mule deer by 15%, elk 46%, and domestic cattle by 53%. Mule deer diets were 10% similar to cattle and 30% to elk. Elk and cattle diets averaged 39% identical on the study area. The low similarity in diet between domestic stock and mule elk suggests that livestock grazing in the study area could be made compatible with the winter range needs of mule deer, but the potential competition between elk and domestic stock needs additional study. Late spring grazing by domestic sheep (i Cook et al. 1962; Van Dyne and Meyer 1964; Wilson et al. 1971; and Olsen and Hansen 1977). However, perusal of the literature over the past three decades clearly indicates that much more is known about the food habits of big game animals on Colorado rangelands than is known about domestic animal food habits on the same lands. The purpose of this paper is to provide information about domestic sheep diets in relation to those of mule deer, domestic cattle (Bos taurus) and elk (Cervus canadensis) on big game winter ranges which may be critical to the successful overwintering of mule deer and elk. An objective was to estimate whether the recent past use of the study areas was resulting in excessive dietary overlaps. Study Area and Procedures The study area was located on the big game winter range of the Alamosa District, Rio Grande National Forest in the San Juan mountains of southcentral Colorado. The study area extends approximately 8 kilometers west of the forest boundary and the mean elevation is 2,833 m ranging from 2,589 m to 3,000 m. The vegetation pattern was uniform throughout the area and three basic plant communities could be distinguished. On the more xeric sites a mixture of shrub steppe and pinyon-juniper vegetation types were found. The major plant species of the shrub steppe were rubber rabbitbrush (Chrysothamnus nauseosus), big sagebrush Authors are graduate research assistant and professor, respectively, Range Science Department, Colorado State University, Fort Collins 80523. We would like to thank J.E. Sazama for his help in organizing the study and T.M. Foppe who performed the analysis of fecal samples. This study was supported in part by the U.S. Forest Service Wildlife Internship Program. 242 (Artemisia tridentata), broom snakeweed (Gutierrezia sarothrae), fringed sagewort (Artemisia frigida), blue grama (Bouteloua gracilis), western wheatgrass (Agropyron smithii), bluegrass (Poa spp.), Arizona fescue (Festuca arizonica), carices (Carex spp.) and needleandthread grass (Stipa comata). The pinyon-juniper type contained pinyon pine (Pinus eduhs), juniper (Juniperus spp.), true mountainmahogany (Cercocarpus montanus), currant (Ribes spp.), fringed sagewort, blue grama, and carices. The major plant species found on mesic sites were ponderosa pine (Pinus ponderosa), douglas fir (Pseudotsuga menziesii), quaking aspen (Populus tremuloides), rose (Rosa spp.), currants, thurber fescue (Festuca thurberi), Arizona fescue, brome (Bromus spp.), prairie junegrass (Koeleria cristata), bluegrass, and carices. Plant names follow those recommended by Beetle (1970). Domestic sheep were released on the study areas in late spring and were herded to higher elevations as the snow melted. Domestic cattle use was heaviest in early summer and progressively decreased as the summer advanced and by late summer most of the cattle had moved to higher elevation ranges. Mule deer and elk typically arrived on the study area in late fall and early winter and remained until late March. In winters with more than average snowfall, they may remain until April or early May. The botanical composition of sheep, cattle, deer, and elk feces was determined by microhistological examination as described by Sparks and Malecheck (1968). Fecal samples were collected from two areas on the winter range during the summer after domestic stock had used the aeas. Each area was approximately one square kilometer in size and was located along the common border of a sheep and cattle allotment. Samples for each herbivore species were derived from 50 single defecations located at random throughout the area. Each subsample was about one cubic centimeter of fecal material. Five microscope slides were made from each sample and 20 fields were examined per microscope slide at 100X magnification. Diet similarity between species of herbivores was calculated using Kulcyznski’s similarity index (Oosting 1956). Results and Discussion The major components of the diet selected by sheep were grasses and sedges (Table 1). Western wheatgrass, blue grama, carices, and Table 1. (Mean &SD) percent relative density of plant fragments in fecal samples of four ungulates in southcentral Colorado from low elevation winter range of big-game. Plant species* Sheep Cattle Deer Elk Agropyron smithii 36 f 5 29 f 27 If 1 14fll Bouteloua gracilis 18f 2 5f 6 If 1 Carex spp. 15f7 4Of35 3f 1 17f 2 Koeleria cristata 9f3 9f 1 2f 2 8f 1 Festuca spp. If1 6f 2 2f 1 14f 17 Artemisia spp. 7f3 1 f 1 16f 2 23f 12 Cercocarpus montanus 12f 2 If 1 Juniperus spp. 10f 6 Pinus edulis 28 f 14 Psuedotsuga menziesii 13f 9 6f 3 *Other taxa in the diets were Aristida, Blepharoneuron, Muhlenbergia. Oryropsis, Pea. Sitanion. Stipa, Ceratoides, Berberis. Chrysothamnus, Descurainia, Eriogonum. Fragaria, Lupinus. Penstemon, Picea. Purshia, Ribes, Rosa, Sheperdia. Sphaeralcea, Symphoricarpos. Yucca and Potentilla in small (<50/o) amounts. JOURNAL OF RANGE MANAGEMENT 34(3), May 1981 Table 2. (Mean &SD) percent dietary overlap of four ungulates in southcentral Colorado when feeding on low elevation winter range of big

An Important Lichen of Southeastern Montana Rangelands

The lichen (Parmelia chlorochroa) was most abundant in sagebrush and grassland vegetation associations, less so in the pine, and absent in riparian types. It was significantly associated with drier sites and bare ground. Lichens appear to have value in reducing erosion, as indicators of intensive grazing, and in contributing to the nutrient quality of soils. Lichens (Lichenes) are often conspicuous and abundant on rangelands of the Western United States, yet have been ignored by most range managers and researchers when quantifying vegetation. Some published studies have presented cover and/or frequency estimates for lichens (Bear and Hansen 1966, Robinson 1969, Eastman and Jenkins 1970, Pendergast and Boag 1970, Mitchell and Smoliak 1971, Anderson et al. 19X2), but failed to identify them by genus or species. Bear and Hansen (1966) later identified the lichen they encountered on southern Colorado rangelands as Parmelia chlorochroo (R.M. Hansen, pen. comm.). Most published studies about lichens deal with taxonomy and distribution (Wetmore 1967). Lichens have been reported to be an important food of large ungulates (Bergerud 1972) and grouse (Ellison 1966) in northern regions. Reindeer lichens (Cladonia spp.) were considered a low quality food by Bergerud (1972) becausetheycontained only2-6% protein. Lichens have been reported in the diets of mule deer (Odocoileus hemionus) (Lavaas 1958, Anderson et al. 1965, Wal