Breeding records for Clark's Grebe in Colorado and Nevada

Described as a new breeding species is Clark's Grebe in Colorado and Nevada.     

Ecology of flannelmouth sucker in the Lee's Ferry tailwater, Colorado River, Arizona

We investigated ecology of flannelmouth sucker ( Catostomus latipinnis ) from 1992 to 1997 in the 26-km Lee's Ferry reach of the Colorado River immediately below Glen Canyon Dam, Arizona. We captured by electrofishing a total of 212 fish and recaptured 52 previously tagged by others. Flannelmouth sucker were captured throughout the tailwater but tended to aggregate about 5 km of the dam, possibly reflecting blockage of historic migration routes. Catch per hour of electrofishing did not differ among years but was greater from November to February than other periods, suggesting seasonal movements of flannelmouth sucker into the tailwater: Mean lengths and weights of fish did not differ among years or seasons. Length frequency analyses also indicated there were no significantly yearly trends in proportion of catch within size classes of fish. Mean condition differed only among seasons and was greatest in February, lowest in August, coinciding respectively with pre- and post-spawning periods of flannelmouth sucker in tributary just down from Lee's Ferry. Recaptured fish migrated from initial tagging locations 1.4-23.1 km downstream from Lee's Ferry. Fifty-nine percent of recaptured fish with known initial tagging locations increased in length, and fish tagged initially as subadults or adults, respectively, grew an average of 45.9 mm and 5.5 mm per year.     

Checklist of the Odonata of Colorado

One hundred and one species of Odonata are recorded for Colorado, including 58 species of Anisoptera (of which 4 are new state records) and 43 Zygoptera (9 new state records). County records are indicated for each. Three major elements are recognized; predominantly eastern species occurring in the plains and mountain valleys east of the Rocky Mountains, Canadian Zone elements occurring principally above 2,440 m (8,000 ft) in the mountains, and Great Basin and western species occurring chiefly west of the mountains. The list is based primarily on the collections at Colorado State University and the University of Colorado, with additional records from the literature and from other collections.     

Asian tapeworm ( Bothriocephalus acheilognathi ) in native fishes from the Little Colorado River, Grand Canyon, Arizona

Examination of gastrointestinal tracts of native cyprinids from the Little Colorado River (LCR) in Grand Canyon, Arizona, 1990-1994, revealed varying rates of prevalence and infrapopulation levels of Asian tapeworm ( Bothriocephalus acheilognathi ). Mean prevalence was 28% (range 0-78%) in humpback chub ( Gila cypha ) and 8% (range 0-46%) in speckled dace ( Rhinichthys osculus ), with infrapopulations as high as 46 and 28, respectively. We also note Asian tapeworm infection of nonnatives common carp ( Cyprinus carpio ), fathead minnow ( Pimephales promelas ), and plains killifish ( Fundulus zebrinus ) from the LCR. Reported pathogenic and chronic effects of this cestode to its definitive hosts add concern for the status of the Grand Canyon population of the federally endangered humpback chub. The rapidity which Asian tapeworm has spread to different drainages of the Colorado River Basin likely portends an eventual cosmopolitan basin distribution in lower elevations suitable to the parasite's thermophilic life history. Such biotic changes must be considered among the most serious threats to conservation and recovery of native fish populations.     

Checklist of the mosses of the Intermountain West, USA

A revised list of the mosses of the Intermountain West, including all of Utah and Nevada and parts of surrounding states, is presented. Recorded are 342 species in 122 genera and 39 families in this region. Nomenclatural and taxonomic changes as well as floristic additions since the publication of Seville Flowers's book are included.     

Microbial spatial heterogeneity in microbiotic crusts in Colorado National Monument. I. Algae

Spatial heterogeneity in visually similar sites under Utah juniper canopy in Colorado National Monument was examined. Sample sites were arranged in a transect 24 m long, such that distances between samples were 0.013 m, 0.03 m, 1.0 m, 12 m, and 24 m. Twenty-five taxa of algae were observed, mostly belonging to Cyanophyta. Algal density varied by more than an order of magnitude within the 46 samples examined. The coefficients of variation for each distance class were very similar, demonstrating that algal patchiness can be as significant on a scale less than 0.013 m as it is on a scale of 24 m. Goodall's random pairing analysis of spatial pattern supported this conclusion by indicating that the minimal area for sampling soil algal crust populations at this site was equal to or less than 0.013 m. Because of the microscale heterogeneity in algal communities in this study, we recommend that future researchers take composite samples if they wish to quantify algae of microbiotic crusts.     

Incidence of the leech Helobdella stagnalis on the Colorado River in west central Colorado

Fifty-seven fish of three genera were taken from the Colorado River in west central Colorado and examined for external parasites. No external parasites were found on Ictalurus. Seven percent of the Hybognathus and 100 percent of the Catastomus were infected with a Hirudinean of the species Helobdella stagnalis.        

Home range of the western jumping mouse, Zapus princeps, in the Colorado Rocky Mountains

Western jumping mice, Zapus princeps, were live - trapped during the summer of 1975 in an aspen forest in the Front Range of the Colorado Rocky Mountains. Home range sizes were calculated using the exclusive boundary strip method, and it was discovered that males had larger home ranges (298 – 3315 m 2 , x = 1743 m 2 ) than females (680 – 1275 m 2 , x = 1041 m 2 ). Mean range length was 96.5 m for males and 78.5 m for females. Spatial relationships showed that females tended to be more territorial than males, based on the females' higher percentage of exclusive home ranges, greater distance between centers of activity, and more uniform spacing.     

Horizontal and vertical diameter of burrows of five small mammal species in southeastern Idaho

Burrow diameters of five small mammal species, Townsend's ground squirrel ( Spermophilus townsendii ), Wyoming ground squirrel ( S. elegans ), Ord's kangaroo rat ( Dipodomys ordii ), montane vole ( Microtus montanus ), and deer mouse ( Peromyscus maniculatus ), were examined. Burrow cross sections were noncircular for all species with horizontal diameters 1.2-1.6 times wider than vertical diameters. Montane vole and deer mouse burrows were the smallest diameter, burrows of Wyoming and Townsend's ground squirrels were the largest, and kangaroo rat burrows were intermediate. Soil bulk density and texture significantly affected burrow diameters of montane voles and deer mice but not the other three species.     

Can Townsend's ground squirrels survive on a diet of exotic annuals?

Southwestern Idaho desert shrub-bunchgrass rangeland is being invaded by fire-prone exotic annuals that permanently dominate the landscape following wildfires. This study was undertaken to describe diets of Townsend's ground squirrels ( Spermophilus townsendii idahoensis ) at four study sites with varying degrees of exotic annual invasion to determine if the squirrels could utilize high proportions of exotic annuals in their diets. Townsend's ground squirrels were collected in March and May of 1987 and 1988, and stomach contents were analyzed using a microhistological technique. Grasses comprised 37-87% of Townsend's ground squirrel diets at the four sites. Native species, especially Sandberg's bluegrass ( Poa secunda ), winterfat ( Ceratoides lanata ), big sagebrush ( Artemisia tridentata ) and six-weeks fescue ( Vulpia octoflora ) constituted 7-96% (x = 47.2%) of the diet, whereas exotic species, especially cheatgrass ( Bromus tectorum ), tumbleweed ( Salsola iberica ), and tansymustards ( Descurainia spp.) made up 4-68% (x = 48.0%) of the diet. At each site 2-4 species comprised >90% of the diet. There was no apparent correlation between the importance values of exotic species at a site and their importance in Townsend's ground squirrel diets.     

History and status of the Franklin's Gull on Malheur National Wildlife Refuge, Oregon

Franklin's Gulls first arrived in southeast Oregon in 1943, but the first nest was not located until 1948. From 1949 to 1964 gull numbers showed annual fluctuations. An increase began in 1965 and continued through 1980. By 1980 an estimated 2500 Franklin's Gulls were nesting on Malheur National Wildlife Refuge, Harney County, Oregon. The species arrives in April and nesting begins by 1 June. Average nest and egg measurements were similar to those from other areas within the species range.     

Habitat and spatial relationships of nesting Swainson's Hawks ( Buteo swainsoni ) and Red-tailed Hawks ( B. jamaicensis ) in northern Utah

A total of 28 Swainson's Hawk ( Buteo swainsoni ) and 30 Red-tailed Hawk ( B. jamaicensis ) nests were found in Cache Valley, Utah, during the summers of 1992 and 1993. All nests were in trees, but only Red-tailed Hawks nested in dead trees (30%). In the intensive study area, nesting densities were 0.10 nests/km 2 for Swainson's Hawk and 0.08 nests/km 2 for Red-tailed Hawk. Nearest-neighbor nest distances were significantly shorter among Swainson's Hawks (1.74 km) than among Red-tailed Hawks (2.83 km). Congeneric nearest-neighbor distances were significantly shorter than conspecific distances for Red-tailed Hawks (1.59 vs 2.83 km) but not for Swainson's Hawks (1.52 vs. 1.74). GIS analysis of habitat types was made for 2-km radii around nest sites. Cropland was the dominant land cover type at nest sites of both species and no significant difference was found between species. Swainson's Hawk nest sites contained significantly more pasture, whereas Red-tailed Hawk nest sites contained significantly more juniper, maple, and sagebrush. Only Red-tailed Hawk nests ( n = 8; 27%) were found on the periphery of the valley at the base of foothills of the Cache Mountains. This preference resulted in a significantly higher elevation for Red-tailed Hawk nest sites. Swainson's Hawk nests occurred only on the valley floor on level terrain. Distance to the nearest paved road and building was very similar for both species, implying that little difference exists in tolerance levels for human activities. Overall, multivariate niche overlap for habitat was high (0.89), indicating a lack of habitat partitioning between these 2 Buteos in Cache Valley.     

Caddisfly (Trichoptera) assemblages along major river drainages in Arizona

Seventy-two caddisfly species in 36 genera and 15 families were collected along the Little Colorado, Verde, Gila, and Colorado rivers in Arizona. Brachycentrids, hydropsychids, limnephilids, and uenoids made up nearly 50% of the assemblage in forested sites above 2200 m. Hydropsychids, hydroptilids, and leptocerids made up 75% of the assemblage in grassland watersheds between 2200 and 1000 m, and 80% at sites below 1000 m in desert watersheds. Species richness averaged 16 at sites above 2200 m elevation, 7 between 2200 and 1000 m, and 3 below 1000 m. H' diversity was typically >3 at sites above 2200 m and <2.5 below 2200 m. Each river had distinct faunas likely due to isolation of drainages across semiarid landscapes. Low S&oslash;rensen similarity values were measured for caddisfly assemblages in the highly regulated Colorado River and the other 3 rivers. Only 17 species were collected at 14 sites along 700 km of the Colorado River. Indicator caddisfly species are provided for altered and less disturbed drainages. We added 7 species not previously reported in Arizona for a total of 154 caddisfly species in the state. We provide a baseline of caddisfly indicators for monitoring changes in ecosystem health during the predicted long-term drought and population expansion in southwestern USA.     

An annotated list of the aquatic insects of southeastern Idaho. Part I. Plecoptera

All of the known records of Plecoptera occurring in southeastern Idaho have been compiled in this list, which includes a number of new records obtained by the authors. The study region includes all of the streams in the Snake River and Great Basin drainages of the state found east of the Wood River and south of the Continental Divide and covers about one-third of the state's 216,413 km 2 area. A total of 71 species were found to occur in the area. These are listed by family and the specific habitats in which each is known to occur are noted.     

Distributional information on birds from egg sets collected by Henry Rogers Durkee in 1870 in southwestern Wyoming

Henry Rogers Durkee collected 74 egg sets of 27 avian species in 1870 at Gilmer, Uinta County, in southwestern Wyoming. Despite the paucity of documented breeding evidence from this region during the late 19th and early 20th centuries, his material at the Smithsonian Institution was generally overlooked and has never been critically examined. Durkee's egg sets included 5 species (Sandhill Crane, Grus candensis ; Northern Rough-winged Swallow, Stelgidoteryx serripennis ; Grasshopper Sparrow, Ammodramus savannarum ; Fox Sparrow, Passerella iliaca ; Cassin's Finch, Carpodacus cassinii ) whose breeding distribution was then poorly known, 25 to more than 70 years before nests and eggs were otherwise documented in Wyoming. Durkee also collected complete egg sets of Lark Bunting ( Calamospiza melanocorys ) over 70 years before breeding was confirmed at other peripheral locations in Wyoming. In addition, Durkee's incomplete egg sets of Grasshopper Sparrow were the 1st western subspecies ( A. s. perpallidus ); his complete egg set and nest of the Fox Sparrow collected at Gilmer constituted the 2nd locality for the species or species group ( P. i. schistacea ). Although the number of egg sets Durkee collected is modest, he made a meaningful contribution to the early history of avifaunal exploration in Wyoming.     

Six new Scolytidae (Coleoptera) from Mexico

Alniphagus africanus Schedl, 1963, and Hylesinus africanus Schedl, 1965, were both transferred to Hylesinopsis and thereby become junior homonyms of H. africanus (Eggers, 1933). The new name H. acaciolens is proposed as a replacement for Schedl's 1963 name and H. secutus as a new name for Schedl's 1965 name. Six species from Mexico are described as new to science, including: Hylocurus atkinsoni, H. crotonis, Monarthrum xalapensis, Pseudochramesus jaliscoensis, Pseudopityophthorus durangoensis , and P. xalapae .     

New synonymy and records of American bark beetles (Coleoptera: Scolytidae)

Alniphagus africanus Schedl, 1963, and Hylesinus africanus Schedl, 1965, were both transferred to Hylesinopsis and thereby become junior homonyms of H. africanus (Eggers, 1933). The new name H. acaciolens is proposed as a replacement for Schedl's 1963 name and H. secutus as a new name for Schedl's 1965 name. Six species from Mexico are described as new to science, including: Hylocurus atkinsoni, H. crotonis, Monarthrum xalapensis, Pseudochramesus jaliscoensis, Pseudopityophthorus durangoensis , and P. xalapae .     

Comparison between plant species in bushy-tailed woodrat middens and in the habitat

Bushy-tailed woodrats ( Neotoma cinera ) collect vegetation and store it in middens. We asked to what extent plant species collected by woodrats reflect the array of species growing in the habitat. Species composition of plant clippings at 20 bushy-tailed woodrat middens in central Colorado were compared to vegetation growing within 30 m of the dens. Amount of overlap between midden and habitat species was low (28-49%) when all taxa were included; however, if only woody taxa were considered, overlap was 71-89%. Sorensen's Index of Similarity exhibited a like pattern; the index increased markedly if only woody taxa were included. Only one plant species not found within 30 m of a den occurred in significant amounts of the middens. Bushy-tailed woodrats collected a wide array of species but were more selective the greater the habitat plant diversity. Results of this and other studies indicate the concordance between midden contents and habitat vegetation decreases with increasing habitat plant diversity. Ancient woodrat middens are nonetheless useful to paleontologists seeking to reconstruct past vegetation associations in woody vegetation is well represented in middens.