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A Habitat Suitability Model For Pygmy Rabbits (Brachylagus Idahoensis) In Southeastern Idaho, Kate I. Gabler, Laura T. Heady, John W. Laundré

Western North American Naturalist

A habitat suitability model was developed for pygmy rabbit (Brachylagus idahoensis) habitat on the Idaho National Engineering and Environmental Laboratory (INEEL) in southeastern Idaho. Suitable pygmy rabbit areas were characterized by greater cover and density of total shrubs and big sagebrush (Artemisia tridentata), as well as greater forb cover. Soil texture also played an important role in distinguishing suitable pygmy rabbit areas from nonuse sites. Principal components analysis (PCA) of several vegetation variables and soil texture was used to develop a habitat suitability model for pygmy rabbit habitat. This model, which can be used to successfully …

Mortality Of The Endangered Wright Fishhook Cactus (Sclerocatus Wrightiae) By An Opuntia-Borer Beetle (Cerambycidae: Moneilema Semipunctatum), Ronald J. Kass

Western North American Naturalist

No abstract provided.

Variation In The Bark Call Of The Red Squirrel (Tamiasciurus Hudsonicus), Osamu Yamamoto, Barry Moore, Leonard Brand

Western North American Naturalist

Calls of the red squirrel (Tamiasciurus hudsonicus; n = 122) were recorded in wild populations from 15 localities in Arizona, New Mexico, Colorado, Utah, Wyoming, Montana, Idaho, and Washington. Computer-generated audiospectrograms of 20- or 30-second samples from a calling bout of each individual were analyzed. Eighteen bark types (distinct forms of the bark call) were identified plus a 19th category that included rarely used, longer bark calls. The frequency of use of each bark type within the sample was recorded for each squirrel. Differences in frequency of use of the various bark types were found among subspecies, within subspecies, …

A Rule-Based Model For Mapping Potential Exotic Plant Distribution, Don G. Despain, T. Weaver, Richard J. Aspinall

Western North American Naturalist

Wildland managers need a method to predict which portions of the lands under their stewardship are susceptible to invasion by exotic plants. We combined a database listing exotic plant species known to occur in major environmental types (habitat types) throughout the northern Rocky Mountains with a digital vegetation map of environmental types for a major national park in the region (Yellowstone National Park) to produce maps of areas potentially threatened by major exotic species. Such maps should be helpful to managers concerned with monitoring and controlling exotic plants.

Comparative Tolerance Of Four Stocks Of Cuttthroat Trout To Extremes In Temperature, Salinity, And Hypoxia, Eric J. Wagner, Ronney E. Arndt, Mark Brough

Western North American Naturalist

Four stocks of cutthroat trout (Oncorhynchus clarki) were exposed to high temperature, high salinity, and low dissolved oxygen to determine inherent differences. The fish tested included 2 stocks of Bonneville cutthroat trout (O. c. utah), a lacustrine stock derived from Bear Lake and a fluvial-origin stock from southern Utah (Manning Meadow Reservoir). The other 2 stocks tested were from Electric Lake (largely Yellowstone cutthroat trout, O. c. bouvieri) and Jackson Hole, Wyoming (fine-spotted Snake River cutthroat trout, O. c. subsp.). Temperature tests were either critical thermal maximum (CTM) or 96-hour trials using juveniles acclimated between …

Drumming Behavior And Life History Notes Of A High-Altitude Colorado Population Of The Stonefly Isoperla Petersoni Needham, John B. Sandberg, Kenneth W. Stewart

Western North American Naturalist

Late instar nymphs and adults of a Colorado Hudsonian zone population of Isoperla petersoni Needham and Christenson were studied during the summer and early fall months of 1998, when stream temperature ranged from 3.3 °C to 8.9 °C. Early and middle instar nymphs were absent from July to October, and nymphs attained maximum size in mid-August during the 2nd week of adult field presence, suggesting a univoltine-slow life cycle. Nymphs were carnivorous and fed primarily on chironomid larvae. Adults were present from August to mid-October, with peak numbers of adult males and females occurring in mid-September and late September, respectively. …

Physiological, Morphological, And Environmental Variation Among Geographically Isolated Cottonwood (Populus Deltoides) Populations In New Mexico, Diane L. Rowland, Lucille Beals, Amina A. Chaudhry, Ann S. Evans, Larry S. Grodeska

Western North American Naturalist

The ability of a plant population to respond and eventually adapt to environmental stress ultimately determines that population's survival. This becomes especially significant in environments where important plant resource levels have radically decreased. Southwestern riparian areas have numerous plant species that are experiencing radical changes in water availability due to construction of dams, and thus their ability to respond to such changes is critical. One such species likely to be greatly affected by these hydrological changes is Populus deltoides var. wislizenii (cottonwood) because it relies heavily on both groundwater and river surface volume as primary water sources. Both water sources …

Index [And Table Of Contents] To Volume 61

Western North American Naturalist

No abstract provided.

Sasquaperla Hoopa, A New Stonefly Genus And Species From Northern California (Plecoptera: Chloroperlidae), B. P. Stark, R. W. Baumann

Western North American Naturalist

Sasquaperla hoopa, a new genus and species of Chloroperlidae, is described from adults and preemergent nymphs collected in the Coast Range of northern California. Males are characterized by the epiproct reduced to a small, tablike structure bearing stiff hairs in a narrow band along the posterior margin. Females are similar to those of Sweltsa, but the nymphs bear several erect bristles lateral to depressed hair patches on the mesosternum. Modified keys are presented for adults and nymphs.

Full Issue, Vol. 61 No. 4

Western North American Naturalist

No abstract provided.

Sexual Dimorphism And Body Temperatures Of Sceloporus Siniferus From Guerrero, México, Julio A. Lemos-Espinal, Geoffrey R. Smith, Royce E. Ballinger

Western North American Naturalist

No abstract provided.

Notes On The Winter Diet Of Short-Eared Owls In Northern California, Raymond J. Bogiatto, John A. Hindley, Rebecca L. Surles

Western North American Naturalist

No abstract provided.

End Matter, Vol. 61 No. 4

Western North American Naturalist

No abstract provided.

Biology And Conservation Of The Coral Pink Sand Dunes Tiger Beetle, Cicindela Limbata Albissima Rumpp, C. Barry Kinsley, James M. Hill

Western North American Naturalist

This study investigated the distribution, abundance, and biology of Cicindela limbata albissima Rumpp, an endemic tiger beetle known only from the Coral Pink Sand Dunes (CPSD) in southwestern Utah. A recently implemented conservation agreement between BLM, USFWS, Utah State Parks, and Kane County protects most of the known habitat of this beetle from off-highway vehicle (OHV) use. A search of collection records and field surveys of 19 Great Basin sand dune sites indicated that this species occurs only at CPSD. Yearly index counts of adults (1992–1998) during peak season in May ranged from 331 in 1997 to 895 in 1993, …

Nanonemoura, A New Stonefly Genus From The Columbia River Gorge, Oregon (Plecoptera: Nemouridae), R. W. Baumann, G.R. Fiala

Western North American Naturalist

Nanonemoura, a new genus of Nearctic Nemouridae, is described to accommodate Nemoura wahkeena Jewett. New descriptions and illustrations are provided for the adult male, adult female, and nymph collected at Wahkeena Spring, Columbia River George, Oregon. A diagnosis is furnished to distinguish the new genus from related genera of the subfamily Nemourinae.

Site And Stand Characteristics Related To White Pine Blister Rust In High-Elevation Forests Of Southern Idaho And Western Wyoming, Jonathan P. Smith, James T. Hoffman

Western North American Naturalist

Successful infection of white pine species by white pine blister rust (WPBR) is contingent upon environmental conditions that are favorable to the spread and development of Cronartium ribicola. Site and stand factors related to this process have been studied elsewhere within the distribution of the disease, but few studies have concentrated on the high-elevation white pine forests of southern Idaho and western Wyoming. We found that mean summer precipitation, average tree diameter, and elevation were the most important variables in 3 logistic regression models of WPBR presence and intensity. The models were tested on a randomly chosen portion of …

Exotic Plants In Early And Late Seral Vegetation Of Fifteen Northern Rocky Mountain Environments (Hts), T. Weaver, D. Gusafson, J. Lichthardt

Western North American Naturalist

We determined the capacity of exotic plants to invade major environmental types of the northern Rocky Mountains. We did this by observing their presence on disturbed and undisturbed sites in relatively well inoculated locations—corridors adjacent to highways—on transects across the mountains in Glacier National Park and Grand Teton National Park and on low-altitude sites between them. We draw 3 primary conclusions. First, of 29 exotics commonly found, the most dominant are intentionally introduced grasses (Agrostis, Bromus, Dactylis, and especially Phleum pratense and Poa pratensis) and legumes (Melilotus, Medicago, and Trifolium) rather than the forbs …

Experimental Manipulations Of Precipitation Seasonality: Effects On Oak (Quercus) Seedling Demography And Physiology, Jake F. Weltzin, Keirith A. Snyder, David G. Williams

Western North American Naturalist

Predicted changes in regional precipitation patterns and soil moisture caused by anthropogenic trace gas emissions may affect the distribution and abundance of woody plants in arid and semiarid regions. To test the response of woody plants to potential changes in precipitation regimes, we manipulated summer and winter precipitation on plots that contained seedlings of Quercus emoryi Torr. (Emory oak), the dominant tree in oak savannas of the southwestern United States. Throughout the growing season, we monitored seedling survival and physiology (predawn leaf water potential, midday instantaneous gas exchange, and leaf carbon isotope discrimination). Seedling survival and physiological performance differed little …

Mule Deer Foraging Preference Among Five Sagebrush (Artemisia L.) Taxa, Carl L. Wambolt

Western North American Naturalist

The hypothesis that sagebrush taxa are equally utilized by mule deer (Odocoileus hemionus hemionus) on winter range was tested. Five taxa were studied for 10 years at 2 locations. The taxa were Artemisia tridentata ssp. tridentata (basin big sagebrush), A. t. ssp. wyomingensis (Wyoming big sagebrush), A. t. ssp. vaseyana (mountain big sagebrush), A. tripartita ssp. tripartita (tall threetip sagebrush), and A. arbuscula ssp. arbuscula (low sagebrush). Possible mule deer preferences were determined each year individually for the 2 sites. Utilization was high enough to conclude all taxa are important forage, but not excessive enough to mask preference. …

Front Matter, Vol. 61 No. 4

Western North American Naturalist

No abstract provided.

Defining And Evaluating Exotic Species: Issues For Yellowstone Park Policy, Ned Hettinger

Western North American Naturalist

Exotics are species that are foreign to an ecological assemblage in the sense that they have not significantly adapted to resident biota or to local abiotic conditions, and resident species have not significantly adapted to them. Although they need not be human introduced nor damaging, when they are, a negative appraisal of such exotic species can be justified. Human introduction of exotics into natural systems typically increases human influence over those systems, thus diminishing their wildness. Valuing nature for its wildness is a rationale for the national parks policy of letting nature take its course. Thus, Yellowstone Park has a …

What Is Natural? Philosophical Analysis And Yellowstone Practice, Paul Schullery

Western North American Naturalist

The following remarks were Paul Schullerys introduction to a roundtable discussion presented during the 5th Biennial Scientific Conference on the Greater Yellowstone Ecosystem, held 11–13 October 1999 in Yellowstone National Park. His remarks serve a second purpose in this issue of the WESTERN NORTH AMERICAN NATURALIST, as they set the stage for and introduce the remaining articles, all of which are papers, presentations, or addresses from that conference. The 1999 Yellowstone Biennial Conference was entitled "Exotic Organisms in Greater Yellowstone: Native Biodiversity Under Siege." Mr. Schullery is a resource naturalist with the National Park Service in Yellowstone.

The Naturalness Of Biological Invasions, Daniel B. Botkin

Western North American Naturalist

No abstract provided.

Mountain Goats In The Greater Yellowstone Ecosytem: A Prehistoric And Historical Context, Paul Schullery, Lee Whittlesey

Western North American Naturalist

Because the relatively recent colonization of portions of Yellowstone National Park by introduced mountain goats (Oreamnos americanus) from public game lands in Montana raises important policy and management questions for the park, it is necessary to understand the prehistoric and early historical record of mountain goats in the Greater Yellowstone Ecosystem. We reviewed previous paleontological, archeological, and historical studies of goat presence and examined a large body of historical material for evidence of goats. Native mountain goat range most closely approached the Greater Yellowstone Ecosystem to the west, but no modern authority claims goats were resident in the …

New Approaches For Sampling And Modeling Native And Exotic Plant Species Richness, Geneva W. Chong, Robin M. Reich, Mohammed A. Kalkhan, Thomas J. Stohlgren

Western North American Naturalist

We demonstrate new multi-phase, multi-scale approaches for sampling and modeling native and exotic plant species to predict the spread of invasive species and aid in control efforts. Our test site is a 54,000-ha portion of Rocky Mountain National Park, Colorado, USA. This work is based on previous research wherein we developed vegetation sampling techniques to identify hot spots of diversity, important rare habitats, and locations of invasive plant species. Here we demonstrate statistical modeling tools to rapidly assess current patterns of native and exotic plant species to determine which habitats are most vulnerable to invasion by exotic species. We use …

Front Matter, Vol. 61 No. 3

Western North American Naturalist

No abstract provided.

Full Issue, Vol. 61 No. 3

Western North American Naturalist

No abstract provided.

Annotated Checklist Of Exotic Vascular Plants In Yellowstone National Park, Jennifer J. Whipple

Western North American Naturalist

Documentation of the arrival of exotic vascular plants in Yellowstone National Park has been sporadic. An annotated checklist of exotic vascular plants is presented, with information about the approximate arrival time in the park of each species and the current extent of the infestation. Yellowstones flora includes 187 exotic vascular plant species (14.8% of the flora), and the park has an extrapolated mean number of exotic species per 10 km² of 47.3. The situation in Yellowstone is compared with other areas in North America. The increase in exotics mirrors a corresponding increase in visitation.

Natural And Unnatural; Wild And Cultural, Holmes Rolston Iii

Western North American Naturalist

Yellowstone National Parks mission and policy can be clarified by analysis of the natural and the unnatural. Nature is a comprehensive word, in some uses excluding nothing; more useful is a contrast distinguishing nature and culture. Specifying "wild nature" denotes spontaneous nature absent human influence. Critics claim that the meaning of wild nature, especially of wilderness, is a foil of culture. Pristine nature, often romanticized, is contrasted with a technological and industrial culture. By this account, wilderness is a social construction.

Nevertheless, wild nature successfully denotes, outside culture, an evolutionary and ecological natural history, which remains present on the Yellowstone …

Effects Of Exotic Species On Yellowstone's Grizzly Bears, Daniel P. Reinhart, Mark A. Haroldson, David J. Mattson, Kerry A. Gunther

Western North American Naturalist

Humans have affected grizzly bears (Ursus arctos horribilis) by direct mortality, competition for space and resources, and introduction of exotic species. Exotic organisms that have affected grizzly bears in the Greater Yellowstone Area include common dandelion (Taraxacum officinale), nonnative clovers (Trifolium spp.), domesticated livestock, bovine brucellosis (Brucella abortus), lake trout (Salvelinus namaycush), and white pine blister rust (Cronartium ribicola). Some bears consume substantial amounts of dandelion and clover. However, these exotic foods provide little digested energy compared to higher-quality bear foods. Domestic livestock are of greater energetic value, but …