Annotated key to Eriogonum (Polygonaceae) of Nevada

Seventy - three species of Eriogonum (Polygonaceae) are reported for Nevada. A key is provided for the identification of these species along with brief notes on their distribution in the state and elsewhere.         

Distribution of the eastern woodrat ( Neotoma floridana campestris ) in southern Nebraska

The eastern woodrat ( Neotoma floridana ) occurs throughout eastern and central parts of the United States. In Nebraska, 3 of 9 subspecies inhabit the state, including N. f. campestris , N. f. attwateri , and N. f. baileyi . We determined distributional limits of N. f. campestris along 2 river systems in southern Nebraska. As observed with other mammalian species in the Great Plains, we suspected that the distribution of woodrats likely had expanded, reflecting continued regulation of rivers and the concomitant increase in forests along them. We documented N. f. campestris at 7 sites in 5 counties, including a recent (since the 1960s) eastward expansion along the Republican River. We observed little movement along the Platte River. The greatest concentration of houses constructed by woodrats occurred in a shelterbelt near the Republican River; otherwise, abundances of houses tended to be greater along the Platte River. We suspect that the distribution of woodrats will continue to change in Nebraska unless breaks exist or are established in riparian forests along the Platte and Republican rivers.     

A new species of Cryptantha (Boraginaceae) from Nevada

Described as new is Cryptantha welshii Thorne & Higgins from the White River Valley of Nye County, Nevada.     

A comparison of riparian condition and aquatic invertebrate community indices in central Nevada

The importance of maintaining healthy riparian communities to sustain natural stream processes and function is well documented. Land management agencies in the West are currently developing methods to assess and monitor riparian community condition to adapt land use practices that would better protect rangeland ecosystems. To determine whether these methods also provide an indication of abiotic and biotic stream condition, we compared the classification system of riparian communities developed by the U.S. Forest Service (USFS) to physical parameters of stream condition and to aquatic invertebrate community assemblages. Thirty-three sites in 19 different streams of the Toiyabe Range in central Nevada were measured for water quality, substrate characteristics, and fish abundance and diversity. We sampled aquatic invertebrates and calculated community indices based on environmental tolerance levels, taxonomic diversity, and abundance of sensitive taxa. USFS personnel classified these sites by dominant riparian plant community type (meadow, willow, or aspen) and ecological status (low, moderate, or high) using plant abundance data, rooting depth, and soil infiltration to determine similarities to potential natural communities. Riparian condition indices as well as community diversity were significantly correlated to proportions of fine and small-diameter substrate in streambeds. Accumulation of silt was significantly related to plant community type, with meadow sites expressing highest proportions. Further examinations indicated that 2 of 6 invertebrate community indices were significantly related to ecological status, with highest diversity levels occurring mainly in willow- and aspen-dominated sites in moderate ecological condition. Nevertheless, we show that several other environmental variables, including substrate characteristics, dissolved oxygen, water temperature, and species richness of fish communities, were more strongly and consistently related to invertebrate assemblage patterns. Our results demonstrate that information on aquatic invertebrates and stream condition could augment the existing riparian classification system and provide useful monitoring tools to more thoroughly examine ecosystem health in rangelands.     

Re-evaluation of the fossil Phoridae (Diptera)

I re-evaluated the known fossil phorids after re-examining much of the Baltic amber and Dominican amber fauna. Many extant genera reported from Eocene Chinese and Eocene/Oligocene Baltic amber are actually not present; instead there are representatives of relatively primitive stem-group taxa. A new genus and species of fossil phorid, Limulomyia tyche, based on a male and a limuloid female, is described from Baltic amber. Some changes in the taxonomy of amber phorids are proposed: Pseudometopina Disney is synonymized with Metopina Schmitz (new synonymy), Diplonevra meunieri Brues is transferred to the genus Godavaria Brown (new combination), Protophorites fimbriatus Brues is considered a junior subjective synonym of Protoplatyphora tertiaria Brues (new synonymy) and Phalacrotophora tertiara Statz is transferred to the genus Gymnophora (new combination). The oldest confirmed dates for extant phorid genera are given.     

Size, age, and density relationships to curlleaf mahogany ( Cercocarpus ledifolus ) populations in western and central Nevada: competitive implications

Size-density-age relationships in curlleaf mountain mahogany communities were studied in 25 study plots, each 30 x 30 m, in western and central Nevada. The influence of total vegetation cover (site potential) and relative mahogany cover (mahogany dominance) on the observed size-density-age relationships was investigated. A positive linear relationship was found between mean mahogany height and mean mahogany age. A positive nonlinear relationship was found between mean mahogany crown volume and mean mahogany age. Negative nonlinear relationships were found between mean mahogany density and mean mahogany age, and mean mahogany density and mean mahogany crown volume. Strong negative relationships were found between the mean combined density of established seedlings, juvenile, and immature mahogany and mean mahogany age and mean mahogany crown volume. Including total cover in the regression relationships between size, age, and density never increased the r 2 value by more than .05. The addition of relative mahogany cover improved the r 2 value for the relationship between mean mahogany density and mean mahogany crown volume by .28. The strong size-density and age-density relationships found indicate that intraspecific competition is probably occurring in the communities sampled, and that established seedlings, juvenile, and immature plants are the first individuals affected. Direct tests are needed to confirm these relationships.     

Reproductive ecology of Dusky Flycatchers in montane meadows of the central Sierra Nevada

Avian species with expansive ranges or those that occupy more than one vegetative association may vary in aspects of their life histories across their ranges. The distribution of Dusky Flycatchers encompasses a variety of vegetative associations, including riparian communities. However, much of the literature on this species details studies conducted in upland areas. Our objectives were to describe the breeding ecology and fecundity of Dusky Flycatchers nesting in montane meadows of the central Sierra Nevada, California. We monitored 36 territories and located 37 Dusky Flycatcher nests in 8 meadows. Average clutch size was 3.9 eggs. Egg laying, incubation, and nestling stages were 4, 15.4, and 16.4 days, respectively. Eighteen nests successfully fledged young, with an average of 3.3 fledglings per successful nest. Nest success was 43% and nest predation was the leading cause of nest failure. Estimated annual fecundity was 1.62 fledglings per pair; however, because all renesting attempts were not located, this should be viewed as the minimum annual fecundity. Dusky Flycatchers we monitored may have had higher fecundity than those nesting in upland areas because riparian areas often have higher arthropod abundances. While the importance of riparian conservation to riparian-obligate bird species is obvious, our study indicates that these areas also may be of value to Dusky Flycatchers that breed in riparian areas and upland areas.     

Regional and seasonal diet of the Western Burrowing Owl in south central Nevada

We examined diets of Western Burrowing Owls ( Athene cunicularia hypugaea ) based on contents of pellets and large prey remains collected year-round at burrows in each of the 3 regions in south central Nevada (Mojave Desert, Great Basin Desert, and Transition region). The most common prey items, based on percent frequency of occurrence, were crickets and grasshoppers, beetles, rodents, sun spiders, and scorpions. The most common vertebrate prey was kangaroo rats ( Dipodomys spp.). True bugs (Hemiptera), scorpions, and western harvest mice ( Reithrodontomys megalotis ) occurred most frequently in pellets from the Great Basin Desert region. Kangaroo rats ( Dipodomys spp.) and pocket mice (Perognathinae) were the most important vertebrate prey items in the Transition and Mojave Desert regions, respectively. Frequency of occurrence of any invertebrate prey was high (>80%) in samples year-round but dropped in winter samples, with scorpions and sun spiders exhibiting the steepest declines. Frequency of occurrence of any vertebrate prey peaked in spring samples, was intermediate for winter and summer samples, and was lowest in fall samples. With the possible exception of selecting for western harvest mice in the Great Basin Desert region, Western Burrowing Owls in our study appeared to be opportunistic foragers with a generalist feeding strategy.     

Hindia sphaeroidalis Duncan from the Devonian of Nevada (Porifera)

The small, spherical, lithistid sponge, Hindia sphaeroidalis Duncan, 1879, is reported from the Devonian and Silurian of the Great Basin for the first time. Devonian specimens came from the Emsian Bartine Member of the McColley Formation from near Roberts Creek, Roberts Mountains, and from the Eifelian part of the Nevada Group near Bishops Creek, north of Wells, Nevada. The Silurian occurrence, questioned because of poor preservation, is from the Laketown Dolomite, on Tunnel Spring Mountain in western Millard County, Utah.     

A new species of fossil Chrysothamnus (Asteraceae) from New Mexico

The new, presumably extinct species, Chrysothamnus pulchelloides, is formally described and illustrated. The plant materials came from Holocene packrat middens. Anatomical and phyletic relationships of the fossil species to extant taxa are discussed.     

Genetic variation of woodrats ( Neotoma cinerea ) and deer mice ( Peromyscus maniculatus ) on montane habitat islands in the Great Basin

Seventeen loci were examined for polymorphism in four populations of Neotoma cinerea and Peromyscus maniculatus on isolated mountain ranges in the Great Basin, one population of each in the Sierra Nevada, and one of each in the Rocky Mountains. All Peromyscus populations had higher levels of heterozygosity than syntopic Neotoma populations.     

Stonefly (Plecoptera) records from the basin ranges of Nevada and Utah

Distributional records are given for 40 stonefly species on 15 isolated mountain ranges in Nevada and Utah.     

Second nesting record and northward advance of the Great-tailed Grackle ( Quiscalus mexicanus ) in Nevada

The second nesting record for the Great - tailed Grackle ( Quiscalus mexicanus ) in Nevada is reported from the central part of the state approximately 240 km north of the previous record. Since 1912 this species has undergone a dramatic northward extension of its previous range in the United States, presumably as a result of increased agricultural irrigation in areas that were previously desert or short - grass prairie.         

Range extension of Onychomys torridus longicaudus (Rodentia: Cricetidae) in northwestern Nevada

Two Onychomys torridus longicaudus Merriam were captured at a site 22 miles W Winnemucca, Humbolt Co., Nevada. This record extends the known range of O. torridus 165 km to the northeast.     

A redescription of the fossil coleoid cephalopod genus Palaeololigo Naef, 1921 (Decapodiformes: Palaeololiginidae) and its relationship to Recent squids

Neocoleoid cephalopods are poorly represented in the fossil record and fossils which can be confidently aligned with extant species are very scarce. The rare Solnhofen genus Palaeololigo is an exception to this, showing marked resemblance to Recent squids. Naef misinterpreted the structure of the fossilized gladius of Palaeololigo and the present study redescribes the genus. The gladius and fossilized fin impressions of Palaeololigo closely resemble that of the extant decapodiform squid genera Bathyteuthis and Chtenopteryx (Superfamily Bathyteuthoidea). The possible relationship between Palaeololigo and the bathyteuthoids and their position in decapodiform phylogenetics is discussed.     

Nesting ecology of Yellow Warblers ( Dendroica petechia ) in montane chaparral habitat in the northern Sierra Nevada

The Yellow Warbler ( Dendroica petechia ) is considered a riparian specialist in much of western North America, but in California it also breeds in a second habitat type: montane chaparral of the Sierra Nevada and southern Cascades. We monitored Yellow Warbler nests in montane chaparral and assessed their poorly known nesting ecology in this habitat. We also conducted point counts in upland habitat throughout the region. We determined habitat associations for Yellow Warblers based on nest site and point-count vegetation data; nests were predominantly in bush chinquapin ( Chrysolepis sempervirens ) and greenleaf manzanita ( Arctostaphylos patula ), and point-count abundance was most strongly associated with high overall shrub cover. The importance of montane chaparral for a number of shrub-dependent Sierran birds is well documented, yet the chaparral is threatened by various practices including fire suppression, closed-canopy-focused forest management, and understory fuels-reduction treatments. Although Yellow Warblers are far more abundant in wet mountain meadow riparian habitat in the region, we recommend that management of montane chaparral habitat consider this species and the requirements of other shrub-nesting birds.     

A new species of Plecia from the Green River Formation and new combinations of fossil Bibionidae (Diptera)

Plecia akerionana , n. sp., is described from the Green River Formation, Colorado, and diagnosed with P. minutula Rice, P. myersi Peterson, and P. rhodopterina Cockerell. Plecia intermedia (Scudder), the genotype of Mycetophaetus , and Plecia creedensis James are transferred to the genus Penthetria , and Hesperinus immutabilis Melander is transferred to Plecia .     

An ecological study of bristlecone pine ( Pinus longaeva ) in Utah and eastern Nevada

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;} This paper presents data on the distribution of Pinus longaeva on the Markagunt Plateau, Utah; and the Snake, Egan, and White Pine ranges of eastern Nevada. It also presents data on the present-day density and age structure of three P. longaeva populations and the growth rates of individual trees within these populations. Conifer species richness and the relative abundance of P. longaeva varies clinally from the Markagunt Plateau to the White Pine Range. The Markagunt Plateau has relatively high conifer species richness (10 species) and low relative abundance of P. longaeva (1%). The White Pine Range has low conifer richness (4 species) and high P. longaeva relative abundance (34%). Individual tree growth rates were low but highly variable in all populations studied. The three populations studied had mixed age structures with a general trend of more younger individuals at the lower elevations. Possible explanations for the present distribution of P. longaeva and the population structures observed are discussed.     

Long-term fluctuations of an isolated populaton of the Pacific chorus frog ( Psuedacris Regilla ) in northwestern Nevada

In 80% of the years between 1975 and 1989 chorus frogs were able to produce offspring that completed metamorphosis and became members of the next generation. During 3 of these 15 years (1975, 1983, and 1986), floods annihilated chorus frogs in the breeding pond. Between 1905 and 1989 this geographically isolated population of Pseudacris regilla , the Pacific chorus frog, located at the western edge of the Great Basin in northwestern Nevada, became reestablished after 10 natural physical disturbances including spring flash floods, numerous kill-offs by sudden drastic rises in water temperature, and stream dry-ups. Ninety percent of the frogs in this population were shades of green with black dorsal speckles and eyestripes. Predators were the belted kingfisher ( Megaceryle alcyon ), western terrestrial garter snake ( Thamnophis elegans ), and domestic house cat ( Felix domestica ).     

Environmental attributes correlating with density of blackbrush ( Coleogyne ramosissima ) shurbs in the Spring Mountains of southern Nevada

Discovery of distinct mid-elevational bands of blackbrush ( Coleogyne ramosissima Torr.) shrublands on desert mountain slopes in the Mojave Desert caused an investigation of the relationships between environmental factors and Coleogyne distribution. Environmental factors were quantitatively examined to determine which were significant predictors of Coleogyne density at upper-elevational limits (ecotones) in the Spring Mountains of southern Nevada. Path analysis revealed significant, direct causal effects of air temperature, soil moisture, soil depth, and percent litter cover on the distribution of Coleogyne . Specifically, air temperature was a significant positive predictor, while soil moisture, soil depth, and percent litter cover were significant negative predictors of Coleogyne density, with the effects of other environmental variables parceled out. Path analysis also indicated that indirect effects of soil pH, bulk density, compaction, percent pore space, organic matter, soil temperature, salinity, cryptogam, and percent bare soil and rock cover on Coleogyne density were substantially more potent than their direct casual effects. Environmental attributes associated with elevational changes correlate with and may determine the density of Coleogyne shrubs at upper ecotones in southern Nevada.