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Research about Arizona, New Mexico, Texas

Source-linked reports with geographic coverage including Arizona, New Mexico, Texas.

6 recordsLinked to original sources
USGS2021

Pathology of Lagovirus europaeus GI.2/RHDV2/b (rabbit hemorrhagic disease virus 2) in native North American lagomorphs

Rabbit hemorrhagic disease, a notifiable foreign animal disease in the US, was reported for the first time in wild native North American lagomorphs in April 2020 in the southwestern US. Affected species included the desert cottontail ( Sylvilagus audubonii ), mountain cottontail ( Sylvilagus nuttallii ), black-tailed jackrabbit ( Lepus californicus ), and antelope jackrabbit ( Lepus alleni ). Desert cottontails ( n =7) and black-tailed jackrabbits ( n =7) collected in April and May 2020 were necropsied at the US Geological Survey National Wildlife Health Center and tested positive for Lagovirus europaeus GI.2, also known as rabbit hemorrhagic disease virus 2 (GI.2/RHDV2/b), by real-time PCR at the US Department of Agriculture's Foreign Animal Disease Diagnostic Laboratory. Gross and microscopic lesions were similar to those reported in European rabbits ( Oryctolagus cuniculus ) and other hare ( Lepus ) species with GI.2/RHDV2/b infection; they included epistaxis (12/13; 92%); massive hepatocellular dissociation (14/14; 100%) and necrosis or apoptosis (11/11; 100%); pulmonary congestion (12/12; 100%), edema (12/13; 92%), and hemorrhage (11/12; 92%); and acute renal tubular injury (3/8; 38%). As in previous reports, massive hepatocellular dissociation and necrosis or apoptosis were the most diagnostically distinct finding. As North American Sylvilagus and Lepus species appear to be susceptible to fatal GI.2/RHDV2/b infection, additional work is needed to understand the host range, pathogenicity, and potential population effects of GI.2/RHDV2/b in North America.

Arizona, New Mexico, Texas↗
USGS2014

Climate change and plant community composition in national parks of the southwestern US: forecasting regional, long-term effects to meet management needs

The National Park Service (NPS) faces tremendous management challenges in the future as climates alter the abundance and distribution of plant species. These challenges will be especially daunting in the southwestern U.S., where large increases in aridity are forecasted. The expected reduction in water availability will negatively affect plant growth and may result in shifts of plant community composition. Synthesis of climate and plant vital sign data from National Park Service Inventory and Monitoring (I&M) networks is essential to provide park managers with important insights into contemporary climate responses and a sound basis to forecast likely future changes at species, community, and ecosystem scales. We describe a collaboration between the U.S. Geological Survey (USGS) and NPS in which we have conducted regional cross-site assessments across the Sonoran and Chihuahuan Deserts to understand plant species responses to past climate and forecast future plant community composition. We also determined whether a widely-implemented vegetation monitoring protocol in these deserts is suitable to track long-term vegetation changes caused by climate and other factors. Our results from these analyses are intended to help natural resource managers identify and prepare for changes in plant cover and community composition and evaluate the efficacy of current monitoring programs.

Arizona, New Mexico, Texas↗
USGS2006

Inferences about winter temperatures and summer rains from the late Quaternary record of C 4 perennial grasses and C 3 desert shrubs in the northern Chihuahuan Desert

Late Quaternary histories of two North American desert biomes—C 4 grasslands and C 3 shrublands—are poorly known despite their sensitivity and potential value in reconstructing summer rains and winter temperatures. Plant macrofossil assemblages from packrat midden series in the northern Chihuahuan Desert show that C 4 grasses and annuals typical of desert grassland persisted near their present northern limits throughout the last glacial-interglacial cycle. By contrast, key C 3 desert shrubs appeared somewhat abruptly after 5000cal.yrBP. Bioclimatic envelopes for select C 4 and C 3 species are mapped to interpret the glacial-interglacial persistence of desert grassland and the mid-to-late Holocene expansion of desert shrublands. The envelopes suggest relatively warm Pleistocene temperatures with moist summers allowed for persistence of C 4 grasses, whereas winters were probably too cold (or too wet) for C 3 desert shrubs. Contrary to climate model results, core processes associated with the North American Monsoon and moisture transport to the northern Chihuahuan Desert remained intact throughout the last glacial-interglacial cycle. Mid-latitude effects, however, truncated midsummer (July-August) moisture transport north of 35° N. The sudden expansion of desert shrublands after 5000cal.yrBP may be a threshold response to warmer winters associated with increasing boreal winter insolation, and enhanced El Niño-Southern Oscillation variability.

Arizona, New Mexico, Texas↗
USGS2004

Divergence among barking frogs ( Eleutherodactylus augusti ) in the southwestern United States

Barking frogs ( Eleutherodactylus augusti ) are distributed from southern Mexico along the Sierra Madre Occidental into Arizona and the Sierra Madre Oriental into Texas and New Mexico. Barking frogs in Arizona and most of Texas live in rocky areas in oak woodland, while those in New Mexico and far western Texas live in rodent burrows in desertscrub. Barking frogs in each of the three states have distinct coloration and differ in sexually dimorphic characters, female vocalization, and skin toxicity. We analyzed advertisement call variation and conducted a phylogenetic analysis using mitochondrial DNA sequences (ND2 and tRNA regions) for barking frogs from these three states. Advertisement calls of frogs from Arizona were significantly longer in duration, higher in frequency, and had longer duration pulses than those of frogs from either New Mexico or Texas; frogs from these latter two sites were indistinguishable in these call variables. Phylogenetic analysis showed deep divisions among barking frogs from the three states. Differences in call structure, coloration, and mitochondrial DNA sequences strongly suggest that barking frogs in Arizona are reproductively isolated from those in New Mexico and Texas. Our results indicate that either northern populations are connected via gene flow through southern Mexico (i.e., they are subspecies as currently recognized), or represent independent lineages as originally described (i.e., western barking frogs, E. cactorum in AZ, and the eastern barking frogs, E. latrans in NM, TX).

Arizona, New Mexico, Texas↗
USGS1975

Selected stratigraphic sections of Cambrian and Ordovician rocks in Arizona, New Mexico, and western Texas

Information from 68 surface localities that I visited was used in the preparation of a report on the Cambrian and Ordovician rocks of Arizona, New Mexico, and western Texas (Hayes, 1975). Descriptions of the stratigraphic sequence at many of these localities have been published in various reports and a majority of those descriptions are reasonably good if not excellent. The rocks at some other localities are either so poorly exposed or faulted or altered that neither useful nor trustworthy sections are measurable there. Included herein are descriptions of part or all of the Cambrian and Ordovician sequence at three localities where the sections have not been described previously in the literature, at two localities whose excellent sections have previously been presented only in generalized graphic form, and at five localities whose previously published descriptions are at considerable variance with my observations in some way (fig. 1). It is doubtful if interest in any of these sections is sufficiently widespread at this time to justify formal publication of these descriptions but they are presented here for those few persons who may have special interest in them. Enclosed in parentheses following the name of each section is the locality number used in my published report (Hayes, 1975). Color terminology for the rocks are adapted from the Rock Color Chart. Bedding thicknesses, when not given in inches, are approximately as follows: thin-bedded for beds up to 6 inches thick, medium-bedded for beds 6 inches to 2 feet thick, thick-bedded for beds 2-5 feet thick; massive for beds more than 5 feet thick. All the sections in this report were measured with the capable assistance of George C. Cone. Fossil collections referred to in this report are described in Hayes (1975).

Arizona, New Mexico, Texas↗