Effects of cobble embeddedness on the microdistribution of the sculpin Cottus beldingi and its stonefly prey

Laboratory experiments were undertaken to assess the effects of three levels of cobble embeddedness on the microdistribution of the sculpin Cottus beldingi and its stonefly prey, Skwala Americana . Experiments were conducted separately and together as predator and prey in temperature- and flow-controlled artificial streams. When tested either separately or together, both the predator sculpin and its stonefly prey occurred in significantly greater numbers on substrata having unembedded cobbles than substrata having half- or completely embedded cobbles. Stonefly densities were greater in substrata having unembedded cobbles even though predator densities within the more embedded cobble patches were significantly lower. These findings support the hypothesis that higher predator densities influence prey densities less than the structural habitat quality of unembedded-cobble patches.     

Effects of livestock grazing exlosure on aquatic macroinvertebrates in a montane stream, New Mexico

Aquatic macroinvertebrate populations inhabiting reaches of a stream within areas excluded from livestock grazing for a decade were markedly different from those in grazed areas when density, biomass, biotic condition indices, and mean chi square indices of the two populations were compared. Increased densities and biomasses of more tolerant forms of macroinvertebrates were observed in grazed reaches. Because pretreatment data were not available, differences in macroinvertebrate populations and relative tolerances of taxa in grazed and ungrazed areas could be as easily attributed to linear changes in stream habitat as to removal of domestic livestock. Results of this study have implications for the design of future research on the effects of livestock grazing on stream environments and biota: (1) baseline/pretreatment information is prerequisite, and (2) the study should take a watershed (ecosystem) approach.     

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.       

Note on mortality of the emerging stonefly Pteronarcys californica on the Jocko River, Montana, USA

Cold air temperatures may have killed several emerging nymphs and adult Pteronarcys californica on the Jocko River, Montana. Some aquatic insect taxa emerge early on the Jocko River, likely due to warm water temperatures in winter and spring. At this location, P. californica emerges approximately 5–7 weeks earlier than it does on many other streams or rivers across the United States. We hypothesize that this earlier emergence may be a mortality factor when cold fronts cause air temperatures to drop below freezing. Other mortality factors are also discussed.     

New Mexico grass types and a selected bibliography of New Mexico grass taxonomy

Collection data, bibliographic citations, and curatorial information on 52 names of New Mexico grass types are compiled. A bibliography of taxonomic research pertinent to the study of New Mexico grasses is cross-referenced with genera known to occur in the state.     

New grass distribution records for New Mexico and the United States

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;} New distribution records are given for 13 grasses now found in New Mexico. One of these, Urochloa panicoides Beauv., is a new distribution record for the United States.     

A survey of breeding and migratory birds southwest of Farmington, New Mexico

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;} The relative abundance and habitat affinities of breeding and migratory waterfowl were documented for a 16,556 ha (40,880 acre) area of the Navajo Indian Reservation, San Juan County, New Mexico. The objective of the 1973 – 1974 study was to obtain baseline data for use as part of an environmental assessment for coal gasification plants and an associated strip mine proposed for an area not previously described in ornithological journals. Roadside breeding - bird surveys resulted in the observation of 26 species of birds, of which the horned lark was most abundant. Additional breeding - bird observations were made during afternoon reconnaissance surveys around stock ponds and arroyos, and by a helicopter survey of cliff - nesting raptors. Nine of 30 raptor nests located were active. Migratory waterfowl surveys were made in September and November at four stock ponds and a marsh on the study area. Peak waterfowl numbers were present in September, when teal and shovelers were the most abundant species. The importance of stock ponds to breeding and migratory birds and the significance of cliffs to nesting raptors were discussed. Details of observations made for five species of birds designated ";threatened"; or ";status undetermined"; were presented.        

Stream channel and vegetation changes in sections of McKnight Creek, New Mexico

Measurements taken at three-year intervals between 1977 and 1985 of channel morphology and vegetation cover between sections inside and outside a cattle exclosure showed that channels increased in depth and width on all plots. Tree canopy cover decreased significantly between 1977 and 1985, but changes in density of trees and shrubs and herbaceous cover were small. Exclusion of cattle use did not prevent channel erosion or deterioration of vegetation; rather, changes were attributed to a wildfire in the headwaters and subsequent storm events that temporarily upset the dynamic equilibrium of the stream.     

Breeding behavior of the Plumbeous Vireo in New Mexico

The Plumbeous Vireo ( Vireo plumbeus ) is a poorly studied songbird species that breeds within the interior western United States and Mexico. We studied the breeding behavior of Plumbeous Vireos within pinyon-juniper habitats in northeastern New Mexico in 1996 and 1997. Over both years we located and monitored 40 nests and conducted behavioral observations throughout the nesting cycle. From these observations we described and compared basic behavioral traits of male and female vireos during their nest-building, egg-laying, incubation, and nestling stages, and their response to potential predators near the nest. Male vireos displayed potential nest sites to females, but the females selected the site to be used and built most of the nest. Vireos often did not initiate egg-laying until 2-3 d after nest completion. The female tended to incubate eggs and brood nestlings more than the male, but both parents contributed equally in provisioning the young. Brown-headed Cowbirds ( Molothrus ater ) parasitized 77% of nests in 1996, 63% in 1997, and parasitism was the primary cause of nest failure in this population. The conspicuousness of vireos around the nest, particularly during the nest-building stage, may contribute to high parasitism levels. Vireo aggression near the nest may also act as a cue to help cowbirds locate nests.     

Winter survival of Northern Pintails in the Middle Rio Grande Valley, New Mexico

In response to continued low population numbers of Northern Pintail ( Anas acuta ) in North America and to increase knowledge of the geographic variation in pintail survival rates, we estimated 126-day (27 October–2 March) survival for male and female pintails wintering in the Middle Rio Grande Valley, New Mexico, during 2001–2002 (SY1) and 2002–2003 (SY2). Sixty-nine adult male and female pintails were marked with radio-transmitters and tracked throughout the study period. Weekly relocation data in relation to study year, sex, time (week), body condition at capture, and hunting seasons were modeled using the known-fate procedure in Program MARK. Year, sex, time, and body condition covariates did not improve model performance in estimating survival, so we used the most parsimonious model to produce an overall winter survival estimate of 0.597 ± 0.077 (95% C.I. = 0.442–0.735). Weekly survival estimates did not differ between hunting and nonhunting seasons. Male and female point estimates did not differ (χ 1 2 = 0.209, P = 0.65). Our adult female survival estimate of 0.639 ± 0.117 (95% C.I. = 0.396–0.827) was 5.5%–28.6% lower than published estimates for adult female pintails in 5 other geographic regions. No winter survival estimates for males in other geographic regions were available for direct comparison with our study. Although relatively small sample sizes may have contributed to the lack of statistical differences in weekly survival between years, sexes, and hunting seasons, as well as to the lack of influence of body condition, relatively abundant water and food resources and absence of hunting in a refuge setting contributed to consistent survival probabilities. Because our low survival estimates, relative to other geographic regions, cannot be attributed to hunting, we postulate that natural causes of mortality play a larger role in pintail survival in our study region than in other wintering regions.     

Spatial and Temporal Variability in Perennial and Annual Vegetation at Chaco Canyon, New Mexico

Annual plant populations in norhtwestern New Mexico were found to be spatially and temporally highly variable. During favorable years annual plant species have patterns of dominance and diversity that are different from those of perennial species. Measurement of perennial plant diversity in plant communities is a poor predictor of productivity. Both perennial and annual components of plant communities should be considered in measurements of diversity and productivity.     

Capture locations of two endangered rodents during a 1902 exploration of the Sacramento Mountains, New Mexico

We investigated localities from which Eutamias atristriatus Bailey, 1913 (= Tamias minimus atristriatus ) and Zapus luteus Miller, 1911 (= Zapus hudsonius luteus ) were collected during a 1902 survey in the Sacramento Mountains, New Mexico, by the United States Biological Survey. The locality from which the holotype of Eutamias atristriatus was collected is restricted to James Canyon rather than the Rio Pe?asco. Locality records indicate that the historical distribution of Zapus hudsonius luteus and its obligate wetland habitat were broader than currently realized.     

New species of Mentzelia (Loasaceae) and Phacelia (Hydrophyllaceae) from New Mexico

New species of Mentzelia and Phacelia are described from northwestern New Mexico, USA, as Mentzelia todiltoensis , N. Duane Atwood & Stanley L. Welsh, and Phacelia sivinskii N. D. Atwood, sp. nov. The new Mentzelia is compared to M. humilis based on similarities in seed, fruit, leaf, and flower morphology and to M. memorabalis in stem, leaf, and fruit morphology. Phacelia sivinskii is compared to P. constancei N. D. Atwood on the basis of seed, leaf, and flower morphology.     

Capnia caryi, an interesting new species of winter stonefly from the American Southwest (Plecoptera: Capniidae)

Capnia caryi , a new species of Nearctic Capniidae, is described from adults collected from high-elevation locations in the Southern Rocky Mountains of southern New Mexico and Arizona. Males are distinguished by their rounded club-shaped epiproct and sclerotized knobs on abdominal terga 8 and 9. Females possess a darkly sclerotized subgenital plate that covers most of tergum 8 and is produced posteriorly as a pair of broadly rounded lobes.     

Physiological, Morphological, and Environmental Variation Among Geographically Isolated Cottonwood (Populus Deltoides) Populations in New Mexico

The ability of a plant population to respond and eventually adapt to environmental stress ultimately determines that population's survival. This becomes especially significant in environments where important plant resource levels have radically decreased. Southwestern riparian areas have numerous plant species that are experiencing radical changes in water availability due to construction of dams, and thus their ability to respond to such changes is critical. One such species likely to be greatly affected by these hydrological changes is Populus deltoides var. wislizenii (cottonwood) because it relies heavily on both groundwater and river surface volume as primary water sources. Both water sources have been extremely impacted by impoundments along southwestern rivers. To understand how New Mexico populations of cottonwood may respond to environmental changes, we quantified environmental differences and characterized physiological and morphological variation among 4 cottonwood populations. Significant differences among study sites in water availability were indicated by both soil and groundwater salinity. The northernmost site, at Abiquiu, had the highest salinity levels in both soil and groundwater, followed by Bernardo, while San Antonio and Corrales sites had the lowest soil salinity. As expected, variation in physiological and leaf morphological characters existed among and within the tree populations, most likely in response to environmental factors. Midday xylem pressure potentials indicated that Abiquiu individuals suffered the greatest water stress and they also had the highest transpiration levels. Because of high specific leaf weights and high photosynthetic levels, cottonwoods at Corrales may better mitigate lower water availability. Such physiological and morphological trait variability among populations is ecologically important and may be of use in present reclamation and conservation efforts in these areas.     

Discovery of a large population of the rare winter stonefly Isocapnia mogila Ricker in the Mad River, California (Plecoptera, Capniidae)

Isocapnia mogila , a rare winter stonefly, is found in good numbers in Humboldt County, California. In the 50 years since this species was described, very few specimens were recorded from only 4 sites in California and Oregon. Emergence seems to be higher in the fall and early winter than in the late winter and spring.     

Habitat features and predictive habitat modeling for the Colorado chipmunk in southern New Mexico

Two subspecies of Colorado chipmunk (state threatened and federal species of concern) occur in southern New MeXico: Tamias quadrivittatus australis in the Organ Mountains and T. q. oscuraensis in the Oscura Mountains. We developed a GIS model of potentially suitable habitat based on vegetation and elevation features, evaluated site classifications of the GIS model, and determined vegetation and terrain features associated with chipmunk occurrence. We compared GIS model classifications with actual vegetation and elevation features measured at 37 sites. At 60 sites we measured 18 habitat variables regarding slope, aspect, tree species, shrub species, and ground cover. We used logistic regression to analyze habitat variables associated with chipmunk presence/absence. All (100%) 37 sample sites (28 predicted suitable, 9 predicted unsuitable) were classified correctly by the GIS model regarding elevation and vegetation. For 28 sites predicted suitable by the GIS model, 18 sites (64%) appeared visually suitable based on habitat variables selected from logistic regression analyses, of which 10 sites (36%) were specifically predicted as suitable habitat via logistic regression. We detected chipmunks at 70% of sites deemed suitable via the logistic regression models. Shrub cover, tree density, plant proximity, presence of logs, and presence of rock outcrop were retained in the logistic model for the Oscura Mountains; litter, shrub cover, and grass cover were retained in the logistic model for the Organ Mountains. Evaluation of predictive models illustrates the need for multi-stage analyses to best judge performance. Microhabitat analyses indicate prospective needs for different management strategies between the subspecies. Sensitivities of each population of the Colorado chipmunk to natural and prescribed fire suggest that partial burnings of areas inhabited by Colorado chipmunks in southern New Mexico may be beneficial. These partial burnings may later help avoid a fire that could substantially reduce habitat of chipmunks over a mountain range.     

Microtopography of microbiotic crusts on the Colorado Plateau, and distribution of component organisms

We analyzed the microtopography of microbiotic soil crusts at 3 sites on the Colorado Plateau of southern Utah and investigated distributions of cyanobacteria and several lichens in distinctive microhabitats created by this topography. At all 3 sites the long axes of linear soil mounds were oriented nonrandomly in a NNW—SSE direction. The conspicuous and consistent orientation of soil mounds may result from a combination of physical and biotic processes. Subtle differences across sites in mound orientation and organismal distribution suggest that these variables may be useful in comparing disturbance histories of crusts retrospectively. Differences in colonization frequencies, abundances, and distributions of microorganisms comprising the crusts, as a function of mound aspect or exposure, suggest that these organisms are associated with particular aspects due to distinctive and favorable microhabitats on these exposures. Polysaccharide sheath material, deposited by cyanobacteria, and associated filaments occurred in greater quantities on ENE than WSW mound exposures, and cover by Collema spp. lichens exhibited the same pattern. Colonization of mounds by common lichen species occurred significantly more frequently on ENE than WSW mound aspects at 2 of 3 sites. In contrast, the 3 most common lichen species, aside from Collema spp., did not exhibit a tendency for greater cover on ENE than WSW mound aspects. Physiological differences between gelatinous cyanolichens and green-algal lichens may explain the different distributional patterns of Collema spp. and the 3 other lichens.     

Systematics and distribution of the winter stonefly genus Capnia (Plecoptera:Capniidae) in North America

The genus Capnia in North America is reviewed and compared to other genera in the family. The genus is divided into 10 species groups. A key to the 51 species of Capnia in North America is given along with a listing of type localities, type repositories, diagnoses, and distributions. New illustrations of structures bearing characters important for identification and classification are presented. An annotation of the list of Capnia of North America given by Stark, Szczytko, and Baumann (1986) reflecting current generic placement of species is produced. From this list Capnia bakeri and sugluka are moved to Mesocapnia . Capnia barbata Frison is placed in synonymy under Capnia decepta . The movement of cygna (synonym of venosa ), elevata, fibula, manitoba, venosa , and wanica to Capnura (Nelson and Baumann, 1987b) is noted. Capnia disala and ensicala are placed in Paracapnia .