First record of the pallid bat ( Antrozous pallidus ) from Montana

A pallid bat ( Antrozous pallidus ) was taken 20 km SE Warren, Carbon County, Montana. This represents a 410 km range extension and a new record for Montana.     

A comparison of epiphytic diatom assemblages on living and dead stems of the common grass Phragmites australis

Diatoms epiphytic on Phragmites australis (Cav.) Trin. ex Steaded stems were collected from a single clone at the southern end of Provo Bay, Utah Lake, Utah. Diatom populations from both living and dead stem sections were analyzed. Species diversity in each sample was high, indicating that the stems provide a relatively stable habitat for diatom epiphytes. Of the 23 genera found, only Gomphonema and Navicula showed significant trends toward stem preference. The diatoms in this study support the current view that Utah Lake is a slightly saline, eutrophic system.     

New grass distribution records for Arizona, New Mexico, and Texas

New distribution records are given for seven grass species now found in Arizona, New Mexico, and Texas.       

Terrestrial vertebrate fauna of the Kaiparowits Basin

This report includes data collected during an investigation by Brigham Young University personnel from 1971 to 1976, as well as a literature review. The fauna of the Kaiparowits Basin is represented by 7 species of amphibians (1 salamander, 5 toads, and 1 tree frog), 29 species of reptiles (1 turtle, 16 lizards, and 12 snakes), 183 species of birds (plus 2 hypothetical), and 74 species of mammals. Geographic distribution of the various species within the basin are discussed. Birds are categorized according to their population and seasonal status. Avian habitat relationships are discussed, and extensions of range are reported for 5 species of birds. Three threatened or endangered avian species occur in the basin. Four avian species seem to have declined significantly in numbers in recent years.     

Distribution of the Shoshone scuplin ( Cottus greenei: Cottidae) in the Hagerman Valley of south central Idaho

Cottus greenei, a potentially threatened species endemic to Idaho, was collected from 49 localities in 25 springs/streams in south central Idaho. Most localities were along the north bank of the Snake River in waters of the Thousand Springs formation, Gooding County. One population was found in a spring in the main Snake River. Another sculpin, Cottus bairdi, was collected with C. greenei at 23 locations in 16 springs/streams. Confusion concerning the type locality of Cottus greenei is discussed.        

A small carnivore survey technique

Thirty-nine previously unpublished reports of the endangered black-footed ferret from Wyoming are listed with dates, locations, number of animals, sources, and comments.     

Pathology of an unusual lumbar condition in a young black bear ( Ursus americanus ) from the Big Bend region of Trans-Pecos Texas

The skeleton of a young American black bear ( Ursus americanus ) possessing asymmetrical distortions of the 5 caudalmost lumbar neural spines was recovered from west Texas. We attribute this abnormality, presumed to be congenital, to the absence or atrophy of the right multifidus muscle straddling L3 and to the series of compensatory muscle adjustments required to maintain spinal alignment. This finding may have important management implications for black bears in Texas, given the possibility that our specimen originates from a partially isolated population. El esqueleto de un oso negro juvenil ( Ursus americanus ) con distorsiones asimétricas de las cinco espinas neurales lumbares inferiores fue descubierto en el oeste de Texas. Atribuimos esta anormalidad, suponiendo que es de origen congénito, a la ausencia o atrofia del músculo multifidus derecho que se extiende a ambos lados de la vértebra L3 y la serie de ajustes musculares compensatorios necesarios para conservar el alineamiento espinal. Este hallazgo podría tener implicaciones importantes para esta especie en Texas, dada la posibilidad de que nuestro espécimen provenga de una población parcialmente aislada.     

Canyon grassland vegetation changes following fire in northern Idaho

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 recovered to prefire coverage by the third postfire year. In the third postfire year, cover of native and nonnative annual species was significantly greater on burned than unburned sites ( P Bromus tectorum cover increased, as expected, on burned plots. Prefire and postfire cover values for Centaurea solstitialis were nearly equal, and there were no significant cover differences between burned and unburned plots in any year. As part of this study, we also evaluated changes in the cover of dominant native and nonnative species with respect to their prefire seral stage on burned and unburned plots. Because our sample sizes were small, we only report community-level trends but suggest that this type of community analysis could make for an interesting future study. Los mosaicos de vegetación nativa y no nativa son comunes en los pastizales del occidente de Norteamérica. Si los administradores de tierras pudieran predecir mejor los cambios en la abundancia de especies nativas y no nativas después de las perturbaciones, se podría mejorar el mantenimiento de la cobertura y diversidad de las plantas nativas. En agosto de 2000, los remanentes de un incendio quemaron terrenos de pradera de cañón durante la supresión de un incendio cerca de Lewiston, Idaho. Un estudio previo registró la composición y cobertura de especies antes del incendio, por lo que pudimos evaluar los cambios en la composición y abundancia de especies en determinados terrenos antes y después del incendio. En general, las quemas de verano no afectaron mucho a las comunidades de pradera. Para el tercer año después del incendio, Pseudoroegneria spicata se había repuesto al nivel de cobertura que tuvo antes del incendio y la cobertura de especies anuales nativas y no nativas fue significativamente mayor ( P Bromus tectorum aumentó en los terrenos quemados. Los niveles de cobertura de Centaurea solstitialis antes y después del incendio fueron casi iguales, y no hubo ninguna diferencia significativa en la cobertura de los terrenos quemados y la de los no quemados en ninguno de estos años. Como parte de este estudio, también evaluamos los cambios en la cobertura de especies dominantes nativas y no nativas con respecto a su estado sucesional previo al incendio en terrenos quemados y no quemados. Debido a que tuvimos un reducido tamaño de muestra, sólo reportamos tendencias a nivel de comunidad, pero sugerimos que esta clase de análisis de comunidades podrían servir como modelo para estudios interesantes en el futuro.     

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.     

Mate sampling in a natural population of Pecos gambusia, Gambusia nobilis

Normal 0 false false false 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-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:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} Much research has been conducted on the mating systems of poeciliid fish in aquaria; however, there are fewer studies that examine mate sampling of these fish in the wild. In general, male poeciliids are characterized as being unselective in their mate choices and will attempt to copulate with seemingly all available females. Females are selective, copulate infrequently, and are often pursued by “ardent” males who may force copulations. To avoid male harassment, females in aquaria will often shelter from males among other females in shoals. Here, we examined the mate-sampling behaviors of male and female Pecos gambusia Gambusia nobilis by following individuals swimming in an outflow pool of Diamond Y Spring in southwestern Texas. In most cases, a male approached a solitary female, followed her briefly, and then left for no apparent reason. Approaching a number of females increased the likelihood that the male would follow one, and the longer a male followed a female, the more likely he was to copulate with her. As females were larger and faster than males, they could avoid males by swimming away from them. We found no evidence of the persistent males that harass seemingly unreceptive females as seen under aquarium conditions, nor did we see females join a shoal to stop pursuit by males. However, the activity of one male following a female did appear to attract other males who would compete to follow and attempt copulation. This competition might ensure that only superior males gain reproductive opportunities. Se han investigado extensamente los sistemas de apareamiento de pecílidos en acuario; no obstante, hay relativamente pocos estudios que examinan la elección de pareja de estos peces en su hábitat natural. Los pecílidos machos no suelen ser selectivos en su elección de pareja y parecen intentar copular con todas las hembras que estén a su alcance. Las hembras son selectivas, no copulan frecuentemente y a menudo las persiguen machos excitados que pueden copular con ellas forzadamente. Para evitar el acosamiento de los machos, en acuario las hembras a menudo se refugian de los machos entre otras hembras en bancos. Para este estudio, examinamos el comportamiento de elección de pareja de gambusias de pecos ( Gambusia nobilis ) machos y hembras al observar algunos individuos en un remanso del Diamond Y Spring en el suroeste de Texas. En la mayoría de los casos, el macho se acercaba a una hembra solitaria, la seguía brevemente y luego se alejaba sin motivo aparente. El acercarse a varias hembras aumentaba la probabilidad de que persiguiera a una de ellas, y cuanto más la seguía, más probable era que copulara con ella. Dado que las hembras son más grandes y más rápidas que los machos, podían eludirlos si no correspondían. No observamos machos persistentes que acosaran hembras aparentemente poco receptivas como se ha documentado en acuario, ni tampoco vimos hembras que se unieran a bancos para evitar la persecución de machos. Pero cuando un macho perseguía una hembra, parecía atraer otros, los cuales competían entre sí para seguirla e intentar copular con ella. Esta competencia podría garantizar que solo los machos superiores tengan oportunidades reproductivas.