Northwestern Texas Research Articles

Mapping Stratigraphy and Artifact Distribution with Unmanned Aerial Vehicle-Based Three-Dimensional Models—A Case Study from the Post Research Area in Northwestern Texas, USA

This study applies UAV-based photogrammetry to map and examine the stratigraphy and archaeological artifact distribution in two localities within the Post research area in northwest Texas. A DJI Inspire 1 UAV equipped with a Zenmuse X5 camera captured nadir and oblique images. These were processed using Agisoft Metashape to generate 3D models. These models enabled the precise mapping of stratigraphic boundaries, revealing the distinctions between Triassic-age bedrock, Pleistocene-age alluvial deposits, and Holocene-age aeolian sediments. Field surveys from 2022 to 2024 documented over 5000 artifacts with sub-centimeter accuracy, including diagnostic projectile points and ceramics. This research highlights the advantages of UAV-derived 3D models in rapidly and accurately documenting stratigraphy and archaeological data. It demonstrates the value of UAV technology for visualizing landscape-scale processes and artifact contexts, offering a new approach to understanding the interactions between geomorphology and archaeology. The findings contribute to advancing UAV applications in both geomorphological and archaeological research.

Garzapelta muelleri gen. et sp. nov., a new aetosaur (Archosauria: Pseudosuchia) from the Late Triassic (middle Norian) middle Cooper Canyon Formation, Dockum Group, Texas, USA, and its implications on our understanding of the morphological disparity of the aetosaurian dorsal carapace.

The Late Triassic Dockum Group in northwestern Texas preserves a rich diversity of pseudosuchian taxa, particularly of aetosaurs. In this contribution, we present Garzapelta muelleri gen. et sp. nov., a new aetosaur from the Late Triassic middle Cooper Canyon Formation (latest Adamanian-earliest Revueltian teilzones) in Garza County, Texas, based on an associated specimen that preserves a significant portion of its dorsal carapace. The carapace of G. muelleri exhibits a striking degree of similarity between that of the paratypothoracin Rioarribasuchus chamaensis and desmatosuchins. We quantitatively assessed the relationships of G. muelleri using several iterations of the matrix. Scoring the paramedian and lateral osteoderms of G. muelleri independently results in conflicting topologies. Thus, it is evident that our current matrix is limited in its ability to discern the convergence within this new taxon and that our current character lists are not fully accounting for the morphological disparity of the aetosaurian carapace. Qualitative comparisons suggest that G. muelleri is a Rioarribasuchus-like paratypothoracin with lateral osteoderms that are convergent with those of desmatosuchins. Although the shape of the dorsal eminence, and the presence of a dorsal flange that is rectangular and proportionately longer than the lateral flange are desmatosuchin-like features of G. muelleri, the taxon does not exhibit the articulation style between the paramedian and lateral osteoderms which diagnose the Desmatosuchini (i.e., a rigid interlocking contact, and an anteromedial edge of the lateral osteoderm that overlaps the adjacent paramedian osteoderm).

HIGH PREVALENCE OF CYTAUXZOON FELIS IN BOBCATS (LYNX RUFUS) ACROSS OKLAHOMA AND OCCURRENCE IN WEST TEXAS, USA.

Cytauxzoonosis is a fatal tick-borne disease in domestic cats caused by infection with the apicomplexan Cytauxzoon felis. Bobcats are the natural wild-vertebrate reservoirs for C. felis, and infections are typically subclinical and chronic in this species. The present study was done to determine the prevalence and geographic distribution of C. felis infection in wild bobcats from Oklahoma and the occurrence in northwestern Texas. Tongue samples from 360 bobcats were collected from 53 counties in Oklahoma and 13 samples from three counties in Texas. For DNA extracted from each tongue sample, a probe-based droplet digital PCR assay was performed targeting the C. felis mitochondrial gene cytochrome c oxidase subunit III (cox3). Prevalence of C. felis infection was calculated for each county sampled, and data from individual counties were combined according to geographic regions and compared using chi-square tests. Overall prevalence of C. felis in bobcats from Oklahoma was 80.0% (95% confidence interval [CI], 75.6-83.8). The prevalence of infection was >90% for bobcats from central, northeastern, south-central, and southeastern regions of Oklahoma, but <68% for bobcats from northwestern and southwestern regions. Bobcats from central counties in Oklahoma were 25.693 times more likely to be infected with C. felis compared to all other bobcats sampled from the state. Higher prevalence estimates of C. felis in bobcats appeared to be in counties where known tick vectors are most common. Occurrence of C. felis in bobcats from northwestern Texas was 30.8% (95% CI, 12.4%-58.0%) based on 13 samples. Results of this study support the utilization of bobcats as sentinel animals to identify geographic areas with risk of C. felis infection to domestic cats.

Golden Eagle Nesting Territory Distribution in Wind Energy Landscapes of the Southern Great Plains

Abstract Deaths of four Golden Eagles (Aquila chrysaetos) due to collision trauma at a new wind energy facility in east-central New Mexico during 2004–2005 prompted concerns about the species' population status in the encompassing Southern Great Plains region, primarily because its breeding distribution there was poorly documented and wind energy development was expanding rapidly. Therefore, we conducted aerial searches for Golden Eagle nests across northeastern New Mexico, northwestern Texas, western Oklahoma, and adjacent portions of Colorado and Kansas during 2006–2009 and 2015–2020. We delineated five Golden Eagle Nest Search Areas (NSAs) with unique physiographic/geological origins. Individual NSAs were searched partially or entirely for up to 8 yr. Collectively, we identified 123 nesting territories (NTs) occupied by Golden Eagles ≥ 1 yr, of which 94 (76%) were in northeastern New Mexico. The most NTs (40) were in the 11,720-km2 Highlands NSA. Greatest NT density (126.6 km2/NT) and shortest NT nearest neighbor distance (7.4 km) were in the 3533-km2 Northern Caprock NSA. Wind turbines existed near (within 3.2 km) eight nests distributed among five of 28 NTs in the Northern Caprock and were planned for sites in two occupied NTs. Elsewhere, only potential turbines were near nests and only within six NTs. The number of nesting territories we found underscores the importance of the Southern Great Plains to Golden Eagles, even though this region lies at the eastern margin of the species' western North American breeding range. Our data provide strong support for protecting breeding habitat from potential threats, particularly those posed by wind energy development, and are also a foundation for long-term population monitoring.

Borderlands History in the Southwestern Historical Quarterly

Borderlands History in the Southwestern Historical Quarterly Omar Valerio-Jiménez (bio) Click for larger view View full resolution First page of the July 1912 issue of the Southwestern Historical Quarterly, which subtly notes the publication's name change. University of North Texas Libraries, the Portal to Texas History, https://texashistory.unt.edu. [End Page 408] For over a century, the Southwestern Historical Quarterly (including the time between 1897 and 1912 when it was known as the Quarterly of the Texas State Historical Association) has been a venue for borderlands scholarship on Texas and the surrounding regions. While the number of articles on borderlands topics have waxed and waned over the years, the journal has consistently promoted scholarship on the Spanish and Mexican periods of the region's history. The Quarterly has featured articles by some of the most renowned borderlands scholars, such as Herbert Bolton, who helped establish the field, but it has also been an avenue for emerging scholars whose research has appeared as journal articles before their books were published. The journal has also published articles by various non-academics whose interests in the state's early history led to contributions to the borderlands field.1 Among the first articles in what [End Page 409] would become known as borderlands history that appeared in the Quarterly were studies focused on Indigenous nations, imperial rivalries, and Spanish exploration.2 The first articles on Indigenous nations were mainly descriptive. They focused on identifying which Native groups lived in what is now Texas, their social organization, the languages spoken by each nation, and their displacement by Anglo Americans. Reflecting the attitudes of Anglo Americans in the late 1890s, these articles demonstrate a Eurocentric bias and advance pernicious stereotypes of Indigenous nations. While discussing the presence of Caddo, Alabama-Coushatta, Lipan Apaches, Comanches, Tonkawas, Karankawas, and others in the region that became Texas, Martin McHenry Kenney lauded the advances in comparative philology that allowed scholars to trace human migrations by analyzing language. Using "tribes" to refer to the Indigenous nations, Kenney discussed the "advance toward civilization" of "savage people."3 He also described alliances among various Indigenous nations and briefly explained their internal social structure of matriarchal and patriarchal groups. Kenney's perspective on "progress" and "civilization" led him to conclude, "There is no instance of a tribe, as such, adopting the political or social organization of civilization."4 But perhaps his most troubling statement is about the Karankawa Indians of the Texas Gulf Coast, when he writes, "The first and worst of these was the Carankawa, inhabiting along the coast from Galveston westward–a tribe of cannibals, noted for their gigantic stature and hideous aspect. … their language was an almost inarticulate guttural, impossible of imitation, and the lowest form of human speech."5 Some articles on Indigenous nations contain important insights despite their Eurocentric interpretations. The essay by Kenney mentioned above notes the advanced skills required to create arrowheads with "uniform construction." The author gestures to the elaborate trade networks among Indigenous nations that led Native groups in western and northwestern Texas to acquire flint rock to make arrowheads. Noting that this flint rock originated in Arkansas and Alabama, the author notes that expansive trade among non-sedentary Indigenous people brought this rock [End Page 410] material to Texas.6 The different types of materials exchanged in such trade networks are not discussed, nor is the possibility that these materials were exchanged among various Indigenous nations from their source to their ultimate destination. This article also speculates about the purpose of earthen mounds in East Texas and references Spanish colonists' accounts of them. Notwithstanding the author's acknowledgement that these mounds took considerable skill and time to complete, the author disparages Indigenous nations by arguing that it was unlikely they were descendants of the mound builders because these nations had a "habitual indisposition to labor."7 The author concludes that "prehistoric races" of Indigenous peoples became "extinct" because they had failed to develop agriculture. Other articles focused on the forced removal of the Cherokee Indians from the American Southeast to Texas and eventually to Indian Territory in present-day Oklahoma. These essays described the Cherokees' acculturation...

Sub-Orbital Flight Demonstration of a 183/540–600 GHz Hybrid CMOS-InP and CMOS-Schottky-MEMS Limb-Sounder

This paper presents an overview of a sub-orbital flight demonstration with a 183 GHz and 540-600 GHz limb-sounding instrument aboard a stratospheric ballooncraft. The 183 GHz band provides soundings of stratospheric H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O and is implemented with a hybrid CMOS-InP receiver architecture which provides excellent sensitivity while remaining compact (162 g) and offering an extremely low DC power consumption (0.62 W). The 540-600 GHz channel sounds stratospheric O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> and uses a combination of a CMOS local oscillator, GaAs Schottky mixer and micro-electro-mechanical-system (MEMS) RF switch for calibration, again offering competitive form factor (1.4 Kg) and low DC power consumption (6.6 W) compared to prior instruments. The instrument was flown on the NASA Reck-Tang Limb-sounding Experiment (ReckTangLE) ballooncraft and performed atmospheric soundings across New Mexico and Northwestern Texas on Oct. 17 2019.

Sub-Regional Variability in Wind Turbine Blade Leading-Edge Erosion Potential

Leading Edge Erosion (LEE) of wind turbine blades leads to significant degradation of aerodynamic performance. Previous research has suggested kinetic energy transferred to the rotating blades from hydrometeor impacts are an important source of LEE. The Southern Great Plains (SGP) of the United States has substantial wind energy development and experiences a high frequency of heavy rain and hail that contribute to atypically high LEE potential. The current study quantifies the degree to which the drivers of LEE exhibit sub-regional variability across a 500,000 km2 area of the SGP. The analysis uses five years of data from nine RADAR stations to characterize the precipitation climate and wind speeds from ERA5. The results illustrate strong spatial gradients in all three atmospheric drivers of LEE: (i) Frequency of power producing wind speeds. (ii) Occurrence of intense precipitation. (iii) Occurrence of hail and maximum hail size. For example, annual precipitation varies by a factor of 10 across Texas and the prevalence of hail events ranges from hundreds of 5-minute events per year to nearly zero. Northwestern Texas has high wind turbine installed capacity and high joint probability of hail and/or heavy precipitation and power-producing wind speeds.

From trash to treasure: Three-dimensional basement imaging with “excess” data from oil and gas explorations

Modern oil and gas seismic surveys commonly use areal arrays that record continuously, and thus routinely collect “excess” data that are not needed for the conventional common reflection point imaging that is the primary goal of exploration. These excess data have recently been recognized to have utility not only in resource exploration but also for addressing a diverse range of scientific issues. Here we report processing of such discarded data from recent exploration surveys carried out in southeastern New Mexico. These have been used to produce new three-dimensional (3-D) seismic reflection imagery of a layered complex within the crystalline basement as well as elements of the underlying crust. This enigmatic basement layering is similar to that found on industry and academic seismic reflection surveys at many sites in the central United States. Correlation of these reflectors with similar features encountered by drilling in northwestern Texas suggest that they may be part of an extensive, continental-scale network of tabular mafic intrusions linked to Keweenawan rifting of the igneous eastcentral Unites States during the late Proterozoic. More importantly, this analysis clearly demonstrates that the new generation of continuously recorded 3-D exploration datasets represent a valuable source of fresh information on basement structure that should be examined rather than discarded. Such basement information is not only important to understanding crustal evolution, it is directly relevant to assessing risks associated with fossil fuel extractions, such as induced seismicity related to waste water injection.

A behavioral landscape perspective on silcrete use in hunter-gatherer lithic technologies along the Southern High Plains Eastern Escarpment of Northwestern Texas (USA)

Ogallala Formation layers and clasts of silcrete, locally known as Macy silcrete, are documented throughout an 83,000-acre research area located along the Southern High Plains eastern escarpment in northwestern Texas (USA). A behavioral landscape perspective has been used to determine how silcrete was incorporated into hunter-gatherer lithic technologies. Results demonstrate that 80% of the silcrete was flaked for making unifacial tools for on-site use. The remaining 20% of the silcrete, however, is transported for continued manufacture and use at other places on the landscape. The behavioral landscape perspective and lithic catena methodology used in this study are important for delineating multiple patterns of lithic use strategies.

Walking the Llano: A Texas Memoir of Place by Shelley Armitage

Reviewed by: Walking the Llano: A Texas Memoir of Place by Shelley Armitage Cynthia Brandimarte Shelley Armitage, Walking the Llano: A Texas Memoir of Place. Norman: U of Oklahoma P, 2016. 203 pp. Cloth, $24.95. Larger than all of New England, the Llano Estacado, or Staked Plains, sprawls some 32,000 square miles and encompasses thirty-three counties in northwestern Texas, plus four counties in northeastern New Mexico. The southern extension of the Great Plains, the Llano, a high mesa sloping at an approximate rate of ten feet per mile toward the southeast, is one of the largest tablelands on the continent. Walking the Llano will appeal to readers who enjoy memoirs combining history, geography, and family and who want to know more about the Plains and the Texas Panhandle. Shelley Armitage's walks meander like the intermittent flow of Middle Alamosa Creek, which crosses the part of the Llano where she grew up. Raised outside of Vega, Texas, she accompanied her father, Bob Armitage, on his retreats [End Page 235] to the family farm from his job at the local bank. Later, when her mother, Dorothy Mae, struggled to keep Armitage Farms going, Shelley, by then an academic, returned during summers to help her. The author's childhood memories blend with those summer returns. Armitage gave purpose to her summers by following the waters of Middle Alamosa Creek to the Canadian River, the largest tributary of the Arkansas River. Flowing over 750 miles from Colorado to Oklahoma, the Canadian River traverses almost 200 miles across Texas, separating the Llano Estacado from the northern High Plains. Being a local, Armitage had the trust of neighbors who allowed her onto their lands to explore creeks and archeological sites. Accompanying her in these explorations were other Panhandle residents known to be keen observers of the Llano. Together, they deciphered the landscape through geological, archeological, and historical lenses. With specialties in women's literary and cultural history, Armitage has taught at universities in Hawai'i, Ethiopia, and Poland. She nevertheless writes as a long-time resident of the Llano, recalling life in the Panhandle, reciting local legends, and remembering childhood friends, some of whom left while others stayed. She skillfully depicts her parents and her brother, Roy, as Llano denizens and lovingly recaptures their lives. She reads stories embedded in the land, plays witness to the layering of time on it, and studies its changes. Her close scrutiny teaches her how the Llano testifies to love and loss and how it connects nature with humankind. Armitage is dismissive of those who live on the land but are not curious about it. Her relationship to the Llano is, by contrast, encompassing. Few writers are as familiar with this part of the Plains, and her book serves as a reminder that the earth endures no matter how many families, friends, and enemies it sustains. The wind turbines on the Llano today will no doubt also pass. Marred only slightly by repetition and relatively unconnected chapters, possibly a consequence of some of the book having previously appeared elsewhere, Walking the Llano is definitely worth the journey. [End Page 236] Cynthia Brandimarte Texas State Parks, Texas Parks and Wildlife Department Copyright © 2017 Western Literature Association

Influence of Habitat Type and Prescribed Burning on Feral Swine Depredation of Artificial Quail Nests

Feral swine (Sus scrofa) have increased both spatially and numerically in the Rolling Plains of northwest Texas. Resource managers have little information on the interrelationships between feral swine and native species such as the northern bobwhite (Colinus virginianus). Nest predation by feral swine could adversely affect bobwhite reproduction. Honey mesquite (Prosopis glandulosa) and redberry juniper (Juniperus pinchotii) are the dominant woody plants in northwestern Texas and prescribed burning is used to manage both species. Two experiments were conducted to determine the extent of feral swine depredation on artificial quail nests. In 1992-93, we monitored nest loss in mesquite and juniper habitats for six weeks. Total depredation reached 85 and 98% after three and six weeks respectively, during 1992, compared to 60 and 92% in 1993. Feral swine depredation of artificial bobwhite nests was 33% across years and was evenly distributed between vegetation types. During three-week periods in June and July 1994, depredation was greater (P<0.001) in an unburned (90%) pasture than in unburned areas within a burned (32%) pasture. Decreased predator activity in the burned pasture was probably due to temporary prey displacement and less forage. Feral swine depredation of artificial bobwhite nests was 14% in 1994. Feral swine could potentially have negative impacts for northern bobwhites in mesquite and juniper habitats of northwest Texas.

Sustaining the 'Quail Wave' in the Southern Great Plains

The southern Great Plains (i.e., Texas and Oklahoma) historically affords some of the best, and currently most stable, northern bobwhite (Colinus virginianus) populations anywhere. However, bobwhite populations have declined in recent years over much of this area, especially east of the 98th meridian. Two subsets of the southern plains, the Rolling Plains (parts of northwestern Texas, western Oklahoma, and western Kansas) and the Rio Grande Plains (south Texas) offer the most expansive, contemporary northern bobwhite habitat throughout its range. Bobwhite habitat in the southern plains is affected primarily by rainfall and rangeland management for livestock. Range management practices (brush control, grazing management) can be prescribed to benefit bobwhite habitat, but a large part of potential bobwhite range in the southern plains suffers from overgrazing and excessive brush control. Farm Bill policies (e.g., Conservation Reserve Program) have had a major impact on dryland agriculture in this region, but their impacts on bobwhites have been only marginally positive (if at all) to date. Income generated from quail hunting in this region currently rivals or exceeds that generated from cattle grazing leases. Accordingly, more landowners are beginning to temper traditional land management goals, and incorporate more quail-friendly practices (i.e., ‘‘brush sculpting’’ and reducing stocking rates). Educational efforts aimed at landowners should strive to implement existing knowledge and develop informed decision-makers. The current demand for quail hunting affords an excellent opportunity to promote, and adopt, management practices that will hopefully sustain the heritage of quail hunting in this region of the bobwhite’s range for future generations.

Solute distribution in the Ogallala Aquifer, Texas: lithium, fluoride, nitrate, chloride and bromide

Spatial patterns of lithium, fluoride, nitrate, chloride and bromide in the Ogallala Aquifer of northwestern Texas were mapped and evaluated. Solute concentrations and depths were compiled for 705 water wells sampled between 2008 and 2014. Lithium concentrations were high relative to typical groundwater; median and maximum concentrations were 66.8 and 2,790 ug/L, respectively. Almost half of the fluoride observations equaled or exceeded the secondary maximum contaminant level (MCL) of 2 mg/L. Many nitrate observations exceeded the MCL of 44.3 mg/L, and several chloride observations exceeded the secondary MCL of 250 mg/L, with a maximum concentration nearly ten times that level. Most bromide observations were less than 0.15 mg/L; however, some observations exceeded 10 mg/L. Several wells had high chloride/bromide ratios and high chloride concentrations. Generally, concentrations of all solutes were higher in the southern part of the aquifer, where wells are relatively shallow. Solute concentrations documented in this study are likely influenced by water–rock interaction within the aquifer, as well as mixing with groundwater in underlying bedrock containing evaporite minerals. Agricultural practices and possibly oilfield activity also affect water quality in the Ogallala Aquifer.

Crop Insurance Loss Performance in 2014

Most payments on 2014 crop insurance policies have been entered into the Summary of Business, a database administered by the Risk Management Agency (RMA). Given relatively complete payment data, an assessment of 2014 loss performance can be made. Overall, loss performance was near “average” when judged relative to the 10-year average loss ratio. In most counties, payments did not exceed total premium. Notable areas of higher losses occurred in 1) western Oklahoma and northwestern Texas and 2) northern Iowa and Minnesota.

Availability of Vaccines for Children Providers in Texas: A County-Level Analysis

s / Annals of Epidemiology 23 (2013) 581e598 590 Results: GEE and REmodels revealedmodest protective effects of training on in-hospital mortality for colectomy (OR1⁄40.79, 95% CI 1⁄4 0.611.02), but not gastrectomy (OR1⁄40.88, 95% CI 1⁄4 0.63-1.22). However, protective effects were more pronounced for high-volume surgeons in highvolume hospitals (vs. low surgeon/hospital volume) (colectomy: OR1⁄40.55, 95% CI 1⁄4 0.47-0.65; gastrectomy: OR1⁄40.46, 95% CI 1⁄4 0.34-.61). Conclusion: Training appears to be less important than surgeon and hospital volume. These findings may have implications for surgical training programs and for regionalization of complex surgical procedures. P39. Availability of Vaccines for Children Providers in Texas: A County-Level Analysis J.M. Eberth, J. Hibbert. University of South Carolina, Columbia, SC Purpose: The Vaccines for Children (VFC) program provides vaccines recommended through the Advisory Committee on Immunization Practices free of charge to children who are aged 0-18 and Medicaid-eligible, un/underinsured, or AI/AN. Ensuring equitable access to these services is a public health priority. The purpose of our study was to examine the availability of VFC providers in Texas from a spatial perspective. Methods: We obtained data on the locations of all VFC-registered providers in Texas from the TX Department of State Health Services Immunization Branch and the San Antonio Metropolitan Health District in April 2011. Using ArcGIS V10.1, wemapped the locations of all the VFCregistered providers and summarized the results at the county-level. Results: Eighteen counties, mostly in the West or Northwestern part of the state, did not have a registered VFC provider. Several of these counties were spatially contiguous, representing a substantial shortage of the vaccine safety-net for portions of Texas. The range of VFC providers per county was 0549 (Mean 1⁄4 15, Median 1⁄4 5). Conclusion: Our preliminary work indicates several pockets of low availability of VFC providers in West and Northwestern Texas, but adequate availability on the whole. Future work will address the spatial accessibility of these VFC providers, accounting for both the supply and potential demand

Preliminary Disease Surveillance in West Texas Quail (Galliformes: Odontophoridae) Populations

Northern Bobwhite (Colinus virginianus) and Scaled Quail (Callipepla squamata) occur throughout northwestern Texas and overall population numbers have been declining for the past 30 yr. This decline has been attributed to habitat loss associated with intensive agricultural practices. We propose that disease may be a contributing factor to decline. Our findings suggest that West Nile virus (WNV) infection may be common in wild quail populations on the Rolling Plains of northwestern Texas. Serum samples (n=301) from wild-caught Northern Bobwhite and Scaled Quail were collected during 2008-10 from seven private properties across the Rolling Plains Region; 5.3% had detectable antibodies against WNV using an enzyme-linked immunosorbent assay. To our knowledge, this is the first report of antibodies to WNV in Scaled Quail and wild-caught Northern Bobwhite from the Rolling Plains of Texas.

Migration and Habitat Preferences of Swainson's Hawks at an Autumn Stopover Site in Northwestern Texas

Unlike most raptors, the Swainson's Hawk (Buteo swainsoni) migrates long distances between breeding and wintering ranges, which elevates the importance of stopover sites for foraging. We conducted three years of fall surveys in the Southern High Plains of Texas. Migrant Swainson's Hawks moved through the area mostly between July and mid-October, peaking in September. Subadults tended to migrate earlier than adults, and light morphs before dark morphs. Favored foraging habitats included silage corn, green beans, and alfalfa, but the hawks foraged primarily where ongoing agricultural activities disturbed prey and made them more available.A diferencia de la mayoría de las rapaces, Buteo swainsoni migra largas distancias entre sus áreas de reproducción e invernada, lo que aumenta la importancia de los sitios de parada para forrajear. Realizamos muestreos durante tres otoños en las Southern High Plains de Texas. Los individuos de B. swainsoni migrantes se desplazaron a través del área generalmente entre julio y la mitad de octubre, con el nivel más alto en septiembre. Los sub-adultos tendieron a migrar antes que los adultos y las formas claras antes que las formas oscuras. Los hábitats de forrajeo favoritos incluyeron silos de maíz, judías verdes y alfalfa, pero los halcones forrajearon principalmente donde las actividades agrícolas en desarrollo disturbaron a las presas y las hicieron más disponibles.

West Nile Virus Infection among Humans, Texas, USA, 2002–2011

We conducted an epidemiologic analysis to document West Nile virus infections among humans in Texas, USA, during 2002–2011. West Nile virus has become endemic to Texas; the number of reported cases increased every 3 years. Risk for infection was greatest in rural northwestern Texas, where Culex tarsalis mosquitoes are the predominant mosquito species.

Urban Amphibians of the Texas Panhandle

&#x0D; &#x0D; &#x0D; &#x0D; Habitat loss, degradation, and fragmentation due to urbanization are implicated in amphibian declines worldwide. Conservation efforts require information on resident species and their habitat interactions, but amphibian ecology is largely unstudied in urban centers of the Southern High Plains. Here, we gathered baseline data on amphibian presence, species richness, and habitat preferences at site-specific and landscape scales during a severe drought year in the city of Lubbock, in northwestern Texas. Ephemeral playa wetlands are characteristic of this landscape. During urbanization, these have been extensively modifiied for stormwater drainage, agriculture, and construction of roads, buildings and neighborhoods. A semi-arid climate with frequent droughts, together with urbanization, could have an adverse effect on resident amphibians. In 2011, we sampled 23 urban lakes for amphibian presence, using a combination of audio, visual, and larval surveys. We detected five amphibian species at seven lakes; Texas Toads (Anaxyrus speciosus) and Spotted Chorus Frogs (Pseudacris clarkii) were the most frequently encountered species. We found significant negative effects of nearby road density on amphibian species presence and richness. We also detected significant negative effects of basic pH on amphibian species richness. These data can be used for prioritizing lakes for amphibian conservation strategies, to monitor ecosystem function in urban wetlands, and to guide future development and restoration efforts.&#x0D; &#x0D; &#x0D; &#x0D;

Identification of Cryptic Hosts for Two Inquiline Parasites of the Seed-Harvester Ant Pogonomyrmex and New Localities for P. anergismus (Hymenoptera: Formicidae)

The harvester ants Pogonomyrmex barbatus and P. rugosus serve as hosts for the parasitic ants P. anergismus and P. colei. Recent molecular studies demonstrated that morphology is unreliable for identification of hosts because the hosts contain cryptic species. Using mitochondrial-DNA sequences, we determined identity of 15 of 16 known populations of hosts, and in 9 instances, the identity of the particular host colony. Hosts are composed of 6 reproductively isolated lineages. While P. colei is known only from a single host, P. anergismus occurs in five distinct hosts and appears to have a much broader geographic range. We report seven new locality records for P. anergismus. Range extensions for P. anergismus in the United States consist of southwestern Texas including Big Bend National Park, northwestern Texas, central New Mexico, and south-central Arizona. We discuss factors that may influence dispersal of parasitic ants and host-parasite co-evolution.