Occurrence of the musk ox, Symbos cavifrons, from southeastern Idaho and comments on the genus Bootherium

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} A set of ovibovine horn cores collected from Pleistocene sediments in southeastern Idaho provides additional evidence for sexual dimorphism in the helmeted musk ox, Symbos cavifrons. Specimens previously assigned to Bootherium sargenti are placed in synonomy with Symbos cavifrons as sexual dimorphs (females). Bootherium bombifrons is a valid taxon and is probably not closely related to Symbos.     

New species of Astragalus (Leguminosae) from Mesa County, Colorado

Named and described is Astragalus debequaeus Welsh from Mesa County, Colorado.         

An Irvingtonian species of Brachylagus (Mammalia: Lagomorpha) from Porcupine Cave, Park County, Colorado

Brachylagus is currently a monotypic genus of uncertain origins and known only from Holocene and late Rancholabrean. A new species of leporid is described from the early and middle Pleistocene (Irvingtonian) deposits of Porcupine Cave, Park County, Colorado. Stratified deposits of the Pit and the Velvet Room, 2 localities within Porcupine Cave, have been dated biochronologically and paleomagnetically fro the middle Irvingtonian and early to middle Irvingtonian, respectively. Brachylagus coloradoensis sp. nov., is characterized by its conserved p3 enamel patterns which are intermediate between B. idahoensis and Hypolagus, and its size which is slightly larger than that of B. idahoensis . This suggest a possible ancestral relationship between Hypolagus and Brachylagus .     

Colorado ground beetles (Coleoptera: Carabidae) from the Rotger Collection, University of Colorado Museum

Ground Beetles from Rotger's collection of Colorado specimens have been identified, principally by the author, and a faunal list of 161 species from 80 localities is presented. The list includes 35 species not previously recorded from Colorado. Comparisons are made with Armin's (1963) carabid list from Boulder County and the diversity of species along transects through four elevational zones from the plains to the alpine.     

New species of oribatids from western Colorado (Acarina: Cryptostigmata, Suctobelbidae)

A new species of Suctobelba, S. tumulata, and a new genus and species, Parisuctobelba septenia, are described from collections of oribatids taken in coal strip-mining spoil banks near Hayden, Colorado. The new species are compared with members of the family from North America and Europe. The new genus is differentiated by a smooth, narrowed sensillum and seven pairs of genital setae. Taxonomic and ecological data are also discussed.     

Fleas associated with the northern pocket gopher ( Thomomys talpoides ) in Elbert County, Colorado

We collected 532 fleas, 526 of which were Foxella ignota ignota , from 247 northern pocket gophers, Thomomys talpoides , in Elbert County, Colorado, over 13 months. Other fleas included 1 Hystrichopsylla dippiei ssp., 3 Spicata rara , 1 Oropsylla idahoensis , and 1 female flea tentatively identified as Oropsylla (Opisocrostis ) sp. These are new records for H. dippiei ssp. and S. rara in Elbert County. Fleas were cleared using standard methods and were placed on microscope slides in Canada balsam. The number of fleas per host ranged from 0 to 26. The highest median number of fleas per host ( n = 5) was in May with a low median ( n = 0) in August. Mean intensity and relative density of fleas peaked in April and May, respectively. Total flea abundance peaked from April through July. Approximately 72% of the male gophers ( N = 99) were infested with fleas, whereas 57% of the females ( N = 148) had fleas. Flea abundance on influenced by hormones of the host. We suggest further randomized studies of fleas on T. talpoides to investigate parasite abundance throughout the year.     

Presettlement vegetation of part of northwestern Moffat County, Colorado, described from remnants

A general botanical inventory of a part of northwestern Moffat County, Colorado, resulted in the location of “ remnants ” of the presettlement vegetation spectrum that are largely unaltered by grazing, logging, or other recent human - related land uses. The 69 samples taken from these remnants were classified into 22 plant associations. Composition, structure, environmental location, geographical range, and response to disturbance are discussed for each association, and a photograph of each is presented. Seven of the 22 associations are apparently restricted to the study area. Restricted associations occur in the more extreme environments of the study area, such as on calcareous substrata or very xeric sites. More mesic sites along ephemeral creeks, on north - facing slopes, or on sandstones support plant associations that have much wider ranges, many of them extending across the northern Great Basin.        

New records for Monotropa hypopithys (Ericaceae) from Colorado

Monotropa hypopithys L., rarely collected in Colorado, was taken five times during 1984. Coupled with previous collections, it is now known from 10 Colorado counties. The cool, moist August of 1984 may have contributed to its apparent ubiquity.     

Food and habitat relationships of Claassenia sabulosa (Plecoptera: Perlidae) in the Upper Colorado River, Colorado

Streambed surveys were conducted along the upper Colorado River, Colorado, to describe the distributions of Claassenia sabulosa larvae in relation to current speed and to determine their diets. We also addressed diel feeding periodicity by sampling during both day and night. Claassenia sabulosa was more abundant in riffle habitats than in runs. A positive relationship existed between C. sabulosa abundance and stream current, with larval size increasing with current speed. Chironomidae, Baetidae, and Simulidae collectively accounted for 93% of the prey found in stonefly guts; however, these categories were not consumed equally by all C. sabulosa . Smaller C. sabulosa primarily ate chironomids, and larger individuals consumed more baetids. Only a slight difference existed in the percentage of empty guts between night- and day-collected stoneflies, and ranges of prey per gut at night were higher than those in the day, suggesting that these stoneflies may forage more intensively at night.     

Spider wasps of Colorado (Hymenoptera, Pompilidae): an annotated checklist

One hundred forty-three species of Pompilidae are recorded from Colorado, slightly more than half the number occurring north of Mexico. Some of these occur principally at higher altitudes or in the northern part of the state; this group includes 5 species of Holarctic distribution. Others (such as the tarantula hawks, Pepsis ) are prevalent across the southern third of the state and range south into New Mexico and often into Mexico. Still others are widely distributed wherever there is friable soil and suitable for nesting. Certain genera are more or less restricted to preying upon certain spider taxa, while others are generalists and a few are cleptoparasites of other Pompilidae.     

First specimen of the spotted bat ( Euderma maculatum ) from Colorado

A spotted bat ( Euderma maculatum ) was picked up at the headquarters of Browns Park National Wildlife Refuge, Moffat County, Colorado, on 29 August 1981.     

Virginia opossum ( Didelphis virginiana virginiana ) from Yavapai County, Arizona

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 virginiana ) es el único marsupial nativo de Estados Unidos. En tiempos recientes, D. virginiana ha expandido su área de distribución tanto por movimientos naturales como por introducciones antropogénicas. Didelphis virginiana se ha encontrado en el sur de Arizona debido a la expansión de la subespecie mexicana ( D. v. californica ) y a introducciones antropogénicas de la subespecie oriental ( D. v. virginiana ). Aquí documentamos la colecta reciente de un tlacuache en el centro de Arizona. También discutimos cómo podría haber llegado hasta allí e informamos sobre los contenidos de su estómago al tiempo de la colecta.     

New species of Mentzelia (Loasaceae) from Grand County, Utah

A new species, Mentzelia (Section Bartonia ) shultziorum , of the Loasaceae (Mentzelioideae) is described. A close relationship with M. multicaulis (Osterh.) Darl. and M. argillosa Darl. is suggested based on the morphology of the flowers, leaves, and seeds.     

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.     

Size, structure, and habitat characteristics of populations of Braya humilis var. humilis (Brassicaceae): an alpine disjunct from Colorado

Size, structure, and habitat characteristics were studied in three populations of Braya humilis var. humilis (C. A. Meyer) Robins, in Gray & Wats. (Brassicaceae), a small, herbaceous perennial of the alpine tundra in central Colorado. There was a significant association between numbers of reproductive, juvenile, and seedling individuals and population location. Plant size within reproductive, juvenile, and seedling size classes varied significantly among three populations. Plots containing Braya had significantly lower total plant cover, a different set of dominant plant species, more rock, bare ground, and less litter than plots without Braya . Braya appears to be restricted to calcareous substrates that experience a moderate level of disturbance, such as solifluction lobes and abandoned roads. Populations are small despite the existence of much potential habitat. Population studies are necessary for active conservation management of Braya .     

Chironomidae (Diptera) of the Colorado River, Grand Canyon, Arizona, USA, I: systematics and ecology

We describe the chironomid midge fauna of the Colorado River between Glen Canyon Dam and Lake Mead, Arizona. This depauperate fauna, consisting of 38 species, is dominated by euryecious Nearctic or Holarctic orthocladine taxa. In addition, a small Neotropical faunal component is represented by Polypedilum obelos Sublette & Sasa and Rheotanytarsus hamatus Sublette & Sasa. The following new synonyms are given: Protenthes riparius Malloch 1915 with Tanypus bellus Loew 1866 [= Procladius (Psilotanypus) bellus (Loew)]; Cricotopus olivetus Boesel 1983 with Cricotopus (Circotopus) annulator (Goetghebuer) 1927; Cricotopus edurus Sublette & Sublette 1971 with Orthocladius infuscatus Malloch 1915 [= Cricotopus (Cricotopus) infuscatus (Malloch)]. The following new species are described: Cricotopus (Cricotopus) blinni Sublette, Cricotopus (Cricotopus) hermanni Sublette, Metriocnemus stevensi Sublette, and Cladotanytarsus marki Sublette. We discuss the distribution and ecology of each chironomid species in this large, regulated, aridlands river.     

Chironomidae (Diptera) of the Colorado River, Grand Canyon, Arizona, USA, II: factors influencing distribution

Biogeographic, flow regulation (water clarity and temperature), and temporal influences affect the composition of the chironomid midge assemblage in the Colorado River between Glen Canyon Dam and Lake Mead. This assemblage is dominated by euryecious Nearctic and Holarctic orthocladine taxa (23 of 38 total species, total weighted relative abundance [WRA] = 0.972) and includes a minor Neotropical component. Chironomid species richness increases over distance downstream from the dam, and dominance shifts across 3 turbidity segments. Eleven species occur in the cold-stenothermic Clearwater (CW) segment between the dam and the 1st perennial tributary (the Paria River, 26 km from the dam). Chironomid diversity increases from 18 to 24 species in the variably turbid (VT) and usually turbid (UT) segments downstream, respectively. Total Cricotopus spp. WRA is negatively correlated with distance (turbidity), white total Chironominae WRA shows the opposite pattern. In contrast to chironomid diversity, species density decreases from 0.42 species/km in the CW segment to 0.19 and 0.08 species/km in the VT and UT segments, respectively. Seasonal dominance shifts slightly from orthocladine Eukiefferiella spp. in winter (WRA = 0.101) to Cricotopus spp. (WRA = 0.165) in summer. Total WRA is lowest in spring (0.191). The assemblage is depauperate compared with other western rivers and has changed over post-dam time.     

Home-range fidelity and use of historic habitat by adult Colorado pikeminnow ( Ptychocheilus lucius ) in the White River, Colorado and Utah

Twelve wild adult Colorado pikeminnow ( Ptychocheilus lucius ), captured in the tailwaters of Taylor Draw Dam on the White River, Colorado, were implanted with radio transmitters and their movement patterns monitored from 1992 to 1994. The spawning migration of these fish was extensive. In 1993, the only full year of the study, the fish migrated an average of 658 km from the White River to spawning sites in the Yampa or Green rivers and back to the White River. Eight of these fish were translocated in the river upstream of the dam in April 1993. These fish and the 4 others below the dam remained in the river until May 1993. All 12 had migrated down the White River to spawning sites in the Green and Yampa rivers by July 1993. The fish that were located above the dam successfully passed over the dam during their downstream migration. Seven fish migrated upstream toward the Yampa River Canyon spawning site and 5 migrated downstream toward the Green River Desolation/Gray Canyon spawning site. Five of 7 Yampa River fish were found at the spawning site. The other 2 were found 5-8 km downstream of the site. One of 5 Green River fish was found at the spawning site, the other 4 between 16 and 62 km upstream of the site. All fish migrated back to the White River by August 1993 and were found near the dam by October 1993. Two fish were recaptured and translocated above the dam in September 1993. Five fish were located below the dam and 2 above the dam in April 1994. By July 1994 seven of the same fish that had migrated toward the Yampa River in 1993 were found at the Yampa Canyon spawning site. At the same time, 3 of 5 fish that migrated toward the Green River in 1993 were found at the Desolation/Gray Canyon spawning site. This included 2 fish that had been found upstream of the site in 1993. The 12 fish traveled an average of 6 km d -1 (range: 4-10 km d -1 ) during the migration period from May through October 1993. Generally, fish moved faster to the spawning site than back from the site to the White River. These fish moved very little within their home ranges in the White River. Six fish tagged in 1992 moved only 0.1-2.3 km in the tailwater reach below Taylor Draw Dam from September 1992 through April 1993. All fish, after their spawning runs, had moved up to or near the dam by October 1993. These fish were not tracked again until April 1994. Their movement patterns in April 1994 were similar to those observed in April 1993. The greatest amount of fish movement in the White River was displayed by the 8 fish placed above Taylor Draw Dam in April 1993 and the 2 placed in Kenney Reservoir in September 1993. They moved 1.1-40.6 km in the river before and after their spawning migration in spring and autumn 1993. These spawning migrations suggest that adult Colorado pikeminnow in the White River were recruited from both Green and Yampa river spawning populations and were presumably imprinted to these respective spawning sites. Those fish placed above Taylor Draw Dam established home ranges in habitats previously occupied by Colorado pikeminnow before the dam was completed. They remained there until they migrated downstream during the spawning period. Although we did not study fish passage, our study demonstrates that adult Colorado pikeminnow will use habitat if access is provided. Translocation of wild adult fish into historic but unoccupied habitats may be a valuable recovery option.     

A new species of Penstemon (Scrophulariaceae) from the Uinta Basin of Utah and Colorado

Named as a new species is Penstemon albifluvis J. L. England. The species is known from the Uinta Basin of Utah and Colorado.     

Esox lucius (Esocidae) and Stizostedion vitreum (Percidae) in the Green River basin, Colorado and Utah

Northern pike, Esox lucius , stocked in the Yampa River in 1977, invaded the mainstream Green River by 1981 and subsequently increased in range and abundance. The speed of this invasion is indicated by two recaptured pike that moved 78 and 110 km, respectively, downstream in about one year. Pike stomachs (n = 123) were usually empty (54.5%), but some contained fish (43%) and nonfish items (2.4%). Red shiner, Notropis lutrensis , and fathead minnow, Pimephales promelas , predominated among the 12 fish species eaten. Walleye, Stizostedion vitreum , presumably introduced to the Green River drainage in the 1960s, was widely distributed but low in abundance. Most of 61 adult walleye stomachs contained food (60.7%) ; of 6 fish species eaten, channel catfish, lctalurus punctatus , and fathead minnow were most frequently consumed. Northern pike and walleye were captured in habitats occupied by endangered Colorado River fishes, particularly Colorado squawfish, Ptychocheilus lucius . Predation on endangered fishes was not detected, but northern pike and walleye consumed at least three other native fishes. The northern pike may pose a threat to endangered fishes due to its population expansion, piscivory, and resource sharing. Diets of northern pike and walleye species should be further evaluated if their abundance increases.