INTRAMOLECULARLY HYPERCOORDINATED ORGANOLEAD COMPOUNDS: (o-MeOC6H4-CH2)PbPh2R, R = Ph, Cl, WITH Pb–O SECONDARY BONDING

The tetrahedral geometry of organolead(IV) compounds can be readily transformed by using an organic ligand containing a dangling-arm oxygen functionality. The acidity of the Pb center results in so-called secondary bonding between O and Pb thereby pushing the geometry at Pb toward a trigonal bipyramidal (tbp) structure. Replacing a phenyl group by a chlorine atom dramatically enhances this phenomenon. Thus for (o-methoxybenzyl) triphenyllead (4), and (o-methoxybenzyl)diphenyllead chloride (5), the Pb–O internuclear distances are 3.362(4) and 2.845(3) Å, respectively; 83% (4) and 70% (5) of the sum of the van der Waals Pb and O radii. Within the group 14 element congeners the structural analysis of the (o-methoxybenzyl)triphenylE compounds, E = Si, Ge, Sn, and now Pb, demonstrates the relative acidities of E are Si < Ge < Sn < Pb.

DIET OF EIGHT SPECIES OF LIZARDS FROM GRANITE GAP, HIDALGO COUNTY, NEW MEXICO

Granite Gap is a desert scrub habitat located in the Chihuahuan Desert in southwestern New Mexico about 200 km from the Texas border. In May 2016, we collected specimens of eight lizard species, six of which range into Texas: Callisaurus draconoides, Cophosaurus texanus, Uta stansburiana, Urosaurus ornatus, Gambelia wislizenii, and Aspidoscelis sonorae (a parthenogenetic species), plus two species not found in Texas: Sceloporus clarkii and Aspidoscelis tigris. We analyzed stomach contents of the preserved lizards and computed diet breadth and overlap for each. All lizard species consumed arthropods only. Considering the entire sample, there was a significant correlation between lizard snout-vent length (SVL) and total volume of arthropods consumed, and between lizard SVL and mean volume per prey item, but not between lizard SVL and number of arthropods consumed. This suggests larger lizards did not consume more arthropods than smaller lizards, but they did consume larger ones. Overall, A. sonorae was the most specialized lizard species at Granite Gap whereas C. texanus seemed to be the most generalized owing to its high numeric and high volumetric diet breadth. The dietary overlap data suggest there were two groups of lizards at Granite Gap: one that consumes a large number and volume of termites (Callisaurus, Cophosaurus, and the two species of Aspidoscelis) and the other that consumes a large number and volume of ants (Uta, Urosaurus, small Sceloporus) plus cicadas when lizard size is large enough to consume them (large Sceloporus and Gambelia).

INVITED ARTICLE FROM THE 2021 TEXAS ACADEMY OF SCIENCE TEXAS DISTINGUISHED SCIENTIST

Donna Shaver is the Chief of the Division of Sea Turtle Science and Recovery at Padre Island National Seashore and the Texas Coordinator of the U.S. Sea Turtle Stranding and Salvage Network. She received the Lifetime Achievement Award from the International Sea Turtle Society in 2018, the 2013 U.S. Fish and Wildlife Service Endangered Species Recovery Champion Award for Agency Partner in 2014, the Corpus Christi Caller Times 2011 Newsmaker of the Year in 2012, and she was the ABC World News Tonight’s Person of the Week on July 29, 2005. She has studied Texas sea turtles since 1980 and is well known for her leadership role in the recovery of the critically endangered Kemp’s ridley sea turtle. Her studies describing sea turtle migratory and foraging habitat use, as well as nesting and stranding trends, have led to increased protections for sea turtles in Texas and beyond. With over 400 scientific publications and presentations, Shaver is distinguished as one of the top sea turtle biologists in the USA and was named the 2021 Texas Distinguished Scientist at the annual meeting of the Texas Academy of Science. Shaver oversees a variety of sea turtle research and conservation projects conducted in Texas, collaborates with other researchers in the USA and Mexico, and provides training and leadership to hundreds of biologists and volunteers working with sea turtles in Texas.

NEW SPECIES RECORDS OF MANTODEA, ORTHOPTERA, AND PHASMATODEA IN THE STATE OF TEXAS (USA)

With its large size and range of habitats, Texas has one of the most diverse insect faunas of the United States with many endemic species. Despite more than a century of active study, knowledge of the insect diversity in Texas remains incomplete. Here, we report 19 species and subspecies records of Mantodea, Orthoptera, and Phasmatodea for the first time in Texas (USA) based on museum specimens. These records include several significant geographic range extensions (from eastern, southern, and western species) such as the phasmid Diapheromera carolina Scudder, the band-winged grasshopper Arphia granulata Saussure, and the mantid Stagmomantis montana Saussure & Zehntner. These records also include the first documentation of Melanoplus torridus (Roberts) and Phaedrotettix gracilis (Bruner) in the United States and the first records of the invasive cricket Velarifictorus micado (Saussure) in Texas. While some of these discoveries only extend known ranges somewhat, others represent disjunct and ecologically different populations.

PRELIMINARY ANALYSIS OF E. COLI GENETIC DIVERSITY IN THE GUADALUPE RIVER: INITIAL APPROACH TO FECAL POLLUTION TRACKING

Four sites in the Guadalupe River were sampled for coliform bacteria from the winter 2016 through spring 2017 to assess the microbiological pollution situation in the river and to identify pollution sources. Numbers of putative coliforms detected ranged from below detection limits to 260 CFUs per 100 mL. Over the time period sampled, coliform levels exhibited strong seasonality, probably linked to the amount of rainfall prior to the sampling date. Molecular analysis of confirmed E. coli isolates demonstrated that the spike in coliform numbers 03 December 2016 was dominated by only two unique fingerprints, suggesting the possibility of a watershed source for fecal contamination in the urban area. The diversity of E. coli fingerprints was much greater in the rural portion of the river, suggesting a variety of coliform sources, probably including wildlife. Further studies are needed to identify and manage sources of fecal pollution.

LATE PLEISTOCENE SHASTA GROUND SLOTH (XENARTHRA) DUNG, DIET, AND ENVIRONMENT FROM THE SIERRA VIEJA, PRESIDIO COUNTY, TEXAS

We present new information about the Late Pleistocene Shasta ground sloth (Nothrotheriops shastensis). Spirit Eye Cave in the Sierra Vieja along the Rio Grande provides the newest evidence that the Shasta ground sloth inhabited further south in the mountains of the southwestern Trans-Pecos, Texas, than has been previously documented. The cave is one of only twelve known Nothrotheriops dung localities. During excavation of the cave, packrat middens and sloth dung were discovered. Two areas within the cave provide radiocarbon dated ground sloth dung and packrat midden macrobotanical remains which permit the reconstruction of the sloth diet and local biotic habitat at 30,800 and 12,900 calibrated YBP. The local community at 30,800 calibrated years ago was a pinyon-juniper woodland with yucca, sandpaper bush, globemallow, cactus, and barberry in the understory based on the packrat midden from the cave. The dung contents indicate that the diet of the sloth included C3 and C4 grasses along with Agave. Data for the local vegetation community and sloth diet from 12,900 years ago indicate that during this late glacial time, the region was still a pinyon-juniper woodland but also contained Celtis, Quercus, and Larrea, among other taxa.

HOME RANGE AND HABITAT SELECTION OF CAVE-DWELLING NORTH AMERICAN PORCUPINES (ERETHIZON DORSATUM) IN CENTRAL TEXAS

North American porcupines (Erethizon dorsatum) have expanded their range into central Texas and are now frequent users of caves as den sites. What remains unknown is how caves affect their home range, and their local habitat preferences. This information is important for management decisions on Joint Base San Antonio – Camp Bullis where novel and abundant porcupine scat in caves could jeopardize federally endangered cave-obligate arthropods by allowing for the invasion of less specialized terrestrial species. To better understand porcupine home range and habitat use at Camp Bullis, we trapped four porcupines at cave entrances and fitted them with GPS collars. The 95% home range averaged 71.3 ha for females and measured 420.6 ha for the male. The 50% core habitat averaged 55.4 ha for females and measured 7.4 ha for the male. Porcupines typically stayed near the den-cave trap site except when visiting more diverse mixed forest patches. At the landscape and point levels, individuals selected for forested cover and avoided open areas. At the home range level, individuals selected for bare ground and roads, which were likely used to get from the cave den site to feed at mixed forest patches. Typically solitary, individuals in this study tolerated sharing a cave. Because of the small sample size and single sampling location, this study represents a pilot study and additional research is needed to establish concrete conclusions. Should cave managers need to limit the cave use by porcupines, a cave gate, exclosure, or reduction of forested cover would make caves less desirable.

SPATIAL ECOLOGY AND HABITAT UTILIZATION OF MONTEZUMA QUAIL IN THE DAVIS MOUNTAINS OF TEXAS

Montezuma quail (Cyrtonyx montezumae) occur throughout the desert mountain ranges in the Trans-Pecos of Texas as well as Arizona, New Mexico, and Mexico. Limited information on life history and ecology of the species is available due to the cryptic nature of the bird. Home range, movements, and preferred habitats have been speculated upon in previous literature with the use of observational or anecdotal data. We used innovative trapping techniques and technologically advanced radio transmitters to assess these ecological parameters for Montezuma quail. The goal of this study was to monitor Montezuma quail to determine home range size, movements, and habitat preference for the Davis Mountains population. We captured a total of 72 birds over the course of two years (2009 – 2010) (36M, 35F, 1 Undetermined). Thirteen individuals with >25 locations/bird were used to estimate the home range, movement, and habitat selection analyses. Home ranges (95% kernel density estimators) averaged 12.83 ha and varied greatly (0.02 – 43.29 ha). Maximum straight-line distances between known locations within home ranges varied from 0.73 – 14.83 km. Distances of movements were greater than previously reported. Preferred habitats consisted of Canyon Mountain Savannah and Foothill Slope Mountain Savannah across three spatial scales. Although our study was able to address some basic ecological attributes of Montezuma quail, additional research is warranted to better understand their population dynamics.