Digital Commons Network^™

Composition Of Forest Stands Used By White-Headed Woodpeckers For Nesting In Washington, Jeffrey M. Kozma

Western North American Naturalist

In this study, I examined the composition of managed ponderosa pine (Pinus ponderosa) forests used by nesting White-headed Woodpeckers (Picoides albolarvatus) along the eastern slope of the Cascade Range in Washington. I sampled trees and snags using the point-centered quarter method to assess species composition, tree and snag density, and stand basal area in 16 forest stands containing White-headed Woodpecker nests. All stands had a history of timber management and 2 had been burned and salvage-logged. Mean live-tree density (≥10.16 cm dbh) was 182.3 trees · ha^–1 (SE = 13.52), mean snag density (≥10.16 cm …

Conservation Status Of The Threatened, Insular San Jose Brush Rabbit (Sylvilagus Mansuetus), Consuelo Lorenzo, Sergio Ticul Álvarez-Castañeda, Jorge Vázquez

Western North American Naturalist

The conservation status and distribution of the insular endemic San Jose brush rabbit (Sylvilagus mansuetus), as well as threats to its population viability, were determined through surveys undertaken since 1995 on San José Island in the Gulf of California, Mexico. Sylvilagus mansuetus is restricted to a specific desert habitat found in the southwestern coastal plains of the island. Vegetation in this habitat is composed primarily of 7 plant species. The extent of rabbit occurrence is only 20 km², and the population density estimate in the most optimal habitat is 25–35 individuals · km^–2. To …

Black-Tailed Prairie Dog Population Dynamics At Scotts Bluff National Monument, Nebraska: A 28-Year Record, Lloyd W. Morrison, David G. Peitz

Western North American Naturalist

Black-tailed prairie dogs, Cynomys ludovicianus, now inhabit a small fraction of their original range in the Great Plains. We monitored a population of black-tailed prairie dogs at Scotts Bluff National Monument, Nebraska, from colonization in 1981 until 2009 (28 years). Colony boundaries were mapped by delineating clip lines and active burrows; population densities were estimated via visual counts. Estimates of total population size revealed 4 distinct periods of changing dynamics: (1) a linear increase, (2) a decline and prolonged depression, (3) an exponential increase, and (4) a period of high variability. Area occupied revealed similar, although less-defined trends, whereas densities …

Canyon Grassland Vegetation Changes Following Fire In Northern Idaho, Corey L. Gucker, Stephen C. Bunting

Western North American Naturalist

Native and nonnative vegetation mosaics are common in western rangelands. If land managers could better predict changes in the abundance of native and nonnative species following disturbances, maintenance of native plant cover and diversity may be improved. In August 2000, during suppression of a wildfire near Lewiston, Idaho, a backing fire burned canyon grassland plots. A previous study had recorded species composition and cover prior to the fire, so we were able to evaluate changes in species composition and abundance on established plots before and after the fire. Overall, summer burning had little effect on the grassland communities. Pseudoroegneria spicata …

Extension Of Southern Range And New Specimens Of The Western Gray Squirrel, Sciurus Griseus Anthonyi (Mammalia: Sciuridae), In Baja California, México, Jonathan Gabriel Escobar-Flores, Gorgonio Ruiz-Campos, Aldo Antonio Guevara-Carrizales, Roberto Martínez-Gallardo

Western North American Naturalist

We documented a southern range extension and new specimens of western gray squirrel (Sciurus griseus anthonyi) for the state of Baja California, México. The most recent specimen was collected in the town Cataviña and represents the southernmost record for the species and subspecies. Repeated observations of individuals in this new location suggest the presence of a marginal population in Mediterranean chaparral–desert scrub transition vegetation.


Documentamos la extension de ámbito más sureño y nuevos especímenes de a ardilla gris occidental (Sciurus griseus anthonyi) para el Estado de Baja California, México. El espécimen más reciente fue recolectado en …

Ecological Intelligence: Rediscovering Ourselves In Nature By Ian Mccallum, Howard O. Clark Jr.

Western North American Naturalist

No abstract provided.

Integrating External Costs Into Water Utility Asset Management : An Application Of The Threshold Break Rate Method, Megan Marsee

Water Resources Professional Project Reports

The goal of an asset management program is to minimize the life-cycle cost of water utility assets, while continuing to provide the service levels expected by utility customers. The life-cycle cost of an asset includes both the utilitys internal costs to maintain the asset, and external costs borne by customers, the community, and the environment when the asset fails. This project demonstrates how to integrate external costs into asset management through an application of the threshold break rate model, a pipe-replacement decision-model that minimizes the life-cycle cost of water mains. The model is employed to determine which six-inch-diameter steel water …

Accelerated Turnover Of Taste Bud Cells In Mice Deficient For The Cyclin-Dependent Kinase Inhibitor P27Kip1, Theresa A. Harrison, Lorraine B. Smith Adams, Preston D. Moore, Marla K. Perna, Jarrod D. Sword, Dennis M. Defoe

ETSU Faculty Works

Background: Mammalian taste buds contain several specialized cell types that coordinately respond to tastants and communicate with sensory nerves. While it has long been appreciated that these cells undergo continual turnover, little is known concerning how adequate numbers of cells are generated and maintained. The cyclin-dependent kinase inhibitor p27Kip1 has been shown to influence cell number in several developing tissues, by coordinating cell cycle exit during cell differentiation. Here, we investigated its involvement in the control of taste cell replacement by examining adult mice with targeted ablation of the p27Kip1 gene.Results: Histological and morphometric analyses of fungiform and circumvallate taste …

Strong Response Of An Invasive Plant Species (Centaurea Solstitialis L.) To Global Environmental Changes., Jeffrey Dukes, Nona R. Chiariello, Scott R. Loarie, Christopher B. Field

Department of Forestry & Natural Resources Faculty Publications

Global environmental changes are altering interactions among plant species, sometimes favoring invasive species. Here, we examine how a suite of five environmental factors, singly and in combination, can affect the success of a highly invasive plant. We introduced Centaurea solstitialis L. (yellow starthistle), which is considered by many to be California’s most troublesome wildland weed, to grassland plots in the San Francisco Bay Area. These plots experienced ambient or elevated levels of warming, atmospheric CO2, precipitation, and nitrate deposition, and an accidental fire in the previous year created an additional treatment. Centaurea grew more than six times larger in response …

Systems-Scale Analysis Reveals Pathways Involved In Cellular Response To Methamphetamine., Lijie Sun, Hong-Mei Li, Manfredo J. Seufferheld, Kent R. Walters Jr, Venu M. Margam, Amber Jannasch, Naomi Diaz, Catherine P. Riley, Weilin Sun, Yueh-Feng Li, William M. Muir, Jun Xie, Jing Wu, Fan Zhang, Jake Y. Chen, Eric L. Barker, Jiri Adamec, Barry R. Pittendrigh

Department of Animal Sciences Faculty Publications

Background

Methamphetamine (METH), an abused illicit drug, disrupts many cellular processes, including energy metabolism, spermatogenesis, and maintenance of oxidative status. However, many components of the molecular underpinnings of METH toxicity have yet to be established. Network analyses of integrated proteomic, transcriptomic and metabolomic data are particularly well suited for identifying cellular responses to toxins, such as METH, which might otherwise be obscured by the numerous and dynamic changes that are induced.

Methodology/Results

We used network analyses of proteomic and transcriptomic data to evaluate pathways inDrosophila melanogaster that are affected by acute METH toxicity. METH exposure caused changes in the …

A Cost-Benefit Analysis Of A Campus Computing Grid, Preston M. Smith

Purdue Polytechnic Masters Theses

Any major research institution has a substantial number of computer systems on its campus, often in the scale of tens of thousands. Given that a large amount of scientific computing is appropriate for execution in an opportunistic environment, a campus grid is an inexpensive way to build a powerful computational resource. What is missing, though, is a model for making an informed decision on the cost-effectives of a campus grid. In this thesis, the author describes a model for measuring the costs and benefits of building a campus computing resource based on the institution’s existing investment in computing hardware.

For …

Preliminary Report On Race And Washington's Criminal Justice System, Task Force On Race And The Criminal Justice System

Seattle University Law Review

For this Report, the Research Working Group reviewed evidence on disproportionality in Washington’s criminal justice system and considered whether crime commission rates accounted for this disproportionality. We found that crime commission rates by race and ethnicity are largely unknown and perhaps unknowable, but that some researchers simply take arrest rates as good proxies for underlying commission rates for all crimes.We found that use of arrest rates likely overstates black crime commission rates for several reasons.68 But even if arrest rates are used as a proxy for underlying crime commission rates, the extent of racial disproportionality is not explained by commission …

Simultaneously Hermaphroditic Shrimp Use Lipophilic Cuticular Hydrocarbons As Contact Sex Pheromones, Dong Zhang, John A. Terschak, Maggy A. Harley, Junda Lin, Jörg D. Hardege

Ocean Engineering and Marine Sciences Faculty Publications

Successful mating is essentially a consequence of making the right choices at the correct time. Animals use specific strategies to gain information about a potential mate, which is then applied to decision-making processes. Amongst the many informative signals, odor cues such as sex pheromones play important ecological roles in coordinating mating behavior, enabling mate and kin recognition, qualifying mate choice, and preventing gene exchange among individuals from different populations and species. Despite overwhelming behavioral evidence, the chemical identity of most cues used in aquatic organisms remains unknown and their impact and omnipresence have not been fully recognized. In many crustaceans, …

The Colby Echo (2011-04-20), Colby College

The Colby Echo

Published by the students of Colby College since 1877, The Colby Echo is the weekly, editorially independent student-run newspaper of Colby College in Waterville, Maine. Published monthly, 1877-1886; semi-monthly, 1886-1897; and weekly, during the academic year, 1898-present.

Fracture In Teeth—A Diagnostic For Inferring Bite Force And Tooth Function, Paul J. Constantino, Brian R. Lawn, James J.-W. Lee, Peter W. Lucas

Biological Sciences Faculty Research

Teeth are brittle and highly susceptible to cracking. We propose that observations of such cracking can be used as a diagnostic tool for predicting bite force and inferring tooth function in living and fossil mammals. Laboratory tests on model tooth structures and extracted human teeth in simulated biting identify the principal fracture modes in enamel. Examination of museum specimens reveals the presence of similar fractures in a wide range of vertebrates, suggesting that cracks extended during ingestion or mastication. The use of ‘fracture mechanics’ from materials engineering provides elegant relations for quantifying critical bite forces in terms of characteristic tooth …

Survival, Reproductive Output, And Transplant Potential Of Penstemon Tubiflorus (Tube Penstemon), Cathy Mabry

Western North American Naturalist

Survival, reproductive output, and transplant success were studied for an Iowa population of Penstemon tubiflorus (tube penstemon), a species that is rare to uncommon through much of its range. The population was discovered in 2003 and is one of only 6 populations that have been documented in Iowa. I began monitoring the new population when 2 cohorts were permanently marked, the first in 2005 and the second in 2007. I estimated survival, flowering, and reproductive output. Then, I introduced greenhouse-grown transplants to 2 new sites and the original site. Survival data showed that P. tubiflorus is a short-lived perennial (approximately …

Genetic Variation In Ecophysiological And Survival Responses To Drought In Two Native Grasses: Koeleria Macrantha And Elymus Elymoides, Huarong Zhang, Laura E. Dewald, Thomas E. Kolb, Dan F. Koepke

Western North American Naturalist

Genetic variation in ecophysiological and survival responses to drought was studied in 2 northern Arizona native grass species, Koeleria macrantha (Ledeb.) Schult. (prairie Junegrass) and Elymus elymoides (Raf.) Swezey. ssp. elymoides (squirreltail). Low- and high-elevation populations of each species were compared in a greenhouse common garden experiment that included simulated drought. Leaf gas-exchange characteristics were significantly affected by simulated drought and often by population elevation, but gas-exchange responses to drought were similar for high- and low-elevation populations. Compared to high-elevation populations, low-elevation populations of both species had higher net photosynthetic rate and predawn water potential, and for E. elymoides had …

Mining Patterns Of The Aspen Leaf Miner, Phyllocnistis Populiella, On Its Host Plant, Populus Tremuloides, Martin L. Morton, Maria E. Pereyra

Western North American Naturalist

Feeding behavior of aspen leaf miner (Phyllocnistis populiella) larvae on quaking aspen (Populus tremuloides) leaves was examined, by using image-analysis software, to determine the pattern and distance of the larvae’s mining trails and measure the surface area of infested leaves and consumed leaf tissue. Mining pathways between hatching and pupation sites were serpentine and generally followed predictable, sequential changes in orientation. This pattern was most obvious in smaller leaves, those with a surface area of about 700 mm² or less. In leaves larger than 700 mm², plasticity in mining behavior increased. The serpentine …

Minibiotus Acadianus (Eutardigrada: Macrobiotidae), A New Species Of Tardigrada From Southern Louisiana, U.S.A., Harry A. Meyer, Megan N. Domingue

Western North American Naturalist

Over 200 species of freshwater and terrestrial water bears (phylum Tardigrada) are known to occur in North America. Of these, 16 species have been collected in Louisiana. Foliose and fruticose lichens collected on 18 April 2010 in Acadia Parish, Louisiana, were stored in paper envelopes and later soaked in tap water overnight. Tardigrade specimens and eggs were extracted and mounted in polyvinyl lactophenol. The samples contained a new species of tardigrade. Minibiotus acadianus sp. n. has a buccal tube with single anterior curvature, 2 macroplacoids and 1 microplacoid. Small gibbosities are present on the fourth pair of legs, in 3 …

Spatial Organization Of Northern Flying Squirrels, Glaucomys Sabrinus: Territoriality In Females?, Jaya R. Smith, Dirk H. Van Vuren, Douglas A. Kelt, Michael L. Johnson

Western North American Naturalist

We determined home-range overlap among northern flying squirrels (Glaucomys sabrinus) to assess their spatial organization. We found extensive home-range overlap among females, and though this overlap could reflect social behavior, we found no evidence of attraction among females, with only one instance of den-sharing. Instead, our results suggest that females share foraging areas but may be territorial in portions of the home range, especially around den trees and during young-rearing. Home-range overlap could also result from the extrinsic effect of forest fragmentation due to timber harvest, which might impede dispersal and force squirrels to cluster on remaining fragments …

Breeding And Parental Care In The Endangered Tehuantepec Jackrabbit (Lepus Flavigularis), Tamara Rioja, Consuelo Lorenzo, Eduardo Naranjo, Laura Scott, Arturo Carrillo-Reyes

Western North American Naturalist

We documented date and duration of each breeding phase, breeding rate, nursing behavior, parental care, and leveret survival of the Tehuantepec jackrabbit (Lepus flavigularis), a critically endangered lagomorph. Between June 2006 and May 2008, we observed 60 adult radio-collared jackrabbits in Oaxaca, México. Tehuantepec jackrabbits exhibit breeding behaviors 250 days out of the year, with a high-intensity period during the rainy season (May–October). Females give birth to 2 leverets 32 days after copulation. Directly after birth, leverets are put into “beds” or “nests,” which are depressions in the ground covered by prairie grass (Jouvea pilosa). Females …

The Ploidy Races Of Atriplex Confertifolia (Chenopodiaceae), Stewart C. Sanderson

Western North American Naturalist

Previous accounts of polyploidy in the North American salt desert shrub Atriplex confertifolia (shadscale) have dealt with the distribution of polyploidy and the morphological and secondary chemical differences between races. The present study amplifies these studies and reveals additional ploidy-flavonoid races, with ploidy levels known to extend from 2x to 12x, and all except 2x and 12x represented by races with and without 6-methoxylation of flavonol compounds. Results of this study show that diploids across their range have about 113% as much DNA per genome as do polyploids and that parallel variation in monoploid genome size between diploids and accompanying …

Exercise Conditioning Decreases Downstream Movement Of Pond-Reared Razorback Suckers Released Into A Stream Environment, Luke A. Avery, David L. Ward, Jane C. Marks

Western North American Naturalist

Despite augmentation stocking efforts, wild populations of razorback suckers (Xyrauchen texanus) continue to decline. Endangered razorback suckers are commonly raised in off-channel ponds until maturity (approximately 300 mm TL) and then stocked into the Colorado River or its tributaries. After fish are stocked, they commonly move large distances downstream. We conducted an experiment to determine if downstream dispersal could be reduced through exercise conditioning. Two groups of razorback suckers, exercised and nonexercised, were released into Fossil Creek, Arizona. Prior to release, a subsample from each treatment group was tested in a laboratory flow chamber. Razorback suckers that had …

Use Of Nonalpine Anthropogenic Habitats By American Pikas (Ochotona Princeps) In Western Oregon, Tom Manning, Joan C. Hagar

Western North American Naturalist

The American pika (Ochotona princeps Richardson) has long been characterized in field guides and popular literature as an obligate inhabitant of alpine talus and as having relatively low dispersal capability. However, recent work reveals pikas to have broader habitat associations than previously reported. Over a large portion of the western slope of the Cascade Range in Oregon, pikas inhabit relatively low-elevation sites far from alpine areas and frequently occur in rocky man-made habitats such as roadcuts or rock quarries. We present observations of pikas in these previously overlooked habitats and discuss implications for (1) the proposed listing of the …

Virginia Opossum (Didelphis Virginiana Virginiana) From Yavapai County, Arizona, R. Nathan Gwinn, Geoffrey H. Palmer, John L. Koprowski

Western North American Naturalist

The Virginia opossum (Didelphis virginiana) is the only marsupial native to the United States. In recent times, D. virginiana has expanded its range through natural movements and anthropogenic introductions. Didelphis virginiana has been present in southern Arizona owing to range expansion by the Mexican subspecies (D. v. californica) and anthropogenic introductions of the eastern subspecies (D. v. virginiana). Here, we document the recent collection of an opossum in central Arizona. We also discuss how it possibly moved there and report on its stomach contents at the time of collection.


El tlacuache norteño (Didelphis …

Occurrence Of Ord's Kangaroo Rat (Dipodomys Ordii) Along Its Eastern Distributional Limit In Nebraska, Greg D. Wright, Keith Geluso

Western North American Naturalist

Changes in land use continue to alter habitats throughout Nebraska, and few studies have examined how such changes affect distributional limits of mammals. The distribution of Ord’s kangaroo rat (Dipodomys ordii) was last examined in eastern Nebraska about 4 decades ago. We examined the current eastern distributional limits ofD. ordii to see whether its range had expanded, contracted, or remained constant in the state since the 1960s. Based on our study, kangaroo rats have experienced little change in distribution during recent decades. Herein, we report on data for 8 counties without prior records and a marginal range …

Melanism In Endangered Mohave Tui Chub Siphateles Bicolor Mohavensis Snyder 1918 (Cypriniformes: Cyprinidae), Sujan M. Henkanaththegedara, Craig A. Stockwell

Western North American Naturalist

Although melanism has been reported in a wide variety of taxa, the presence of melanic individuals is relatively rare in fishes. Melanism in Mohave tui chub (Siphateles bicolor mohavensis), an endangered endemic of the Mojave Desert in California, is reported from 2 of 4 surveyed populations. The typical body color varies from dark brown to olive brown dorsally and is whitish ventrally; sides are silvery or golden, and fins are pale yellow to dusky red. While conducting population censuses in 2007–2008, we found 4 melanic Mohave tui chubs from 2 of 4 surveyed habitats. Two of 1049 fish …

The Relationships Among Plant Cover, Density, Seed Rain, And Dispersal Of Bromus Tectorum In High-Elevation Populations, Andrew R. Kanarek, Rebecca Hufft Kao

Western North American Naturalist

The invasive species Bromus tectorum L. is recognized as one of the most ecologically and economically devastating weeds in the western United States. Although B. tectorumhas been studied extensively, few studies have examined its dispersal and spread. We collected data from sites with B. tectorum in and around Rocky Mountain National Park to quantify the relationships between plant cover/density and seed rain and dispersal distance. Results suggest that there is a positive relationship between density within a patch and local seed rain and that B. tectorum exhibits relatively limited short-distance dispersal (where seeds fell in close proximity to plants …

Front Matter, Vol. 71 No. 1

Western North American Naturalist

No abstract provided.

End Matter, Vol. 71 No. 1

Western North American Naturalist

No abstract provided.