2019 Chihuahuan Desert Conference Session 4 – Abstracts and Bios

Session 4 – Plants, Reptiles and Amphibians, Invertebrates

Topic: Rare Plants, Rare Habitats: Musings on the Geobotany of the Big Bend Area 

Presenter: Betty Alex

Session Abstract: Searching for populations of rare plants can be a daunting endeavor. Much energy and time is often spent looking for populations based on soils already identified in a known location.  Often riparian and mesic locations are targeted to be searched based on the idea that rare plants need ‘gentle’ habitats where they are not stressed. During two rare plant projects, the author discovered that, in the hot dry desert, geologic formations appear to have more effect on the favored habitat of rare plants, and may, in fact be the controlling factor. The exceptionally complex geology of the Big Bend area has apparently been conducive to the production of numerous plant species that are considered ‘rare’ because they have very limited habitat and populations.  That geologic complexity coupled with the low level of human interference in the area has created dozens of unusual habitats that supports hundreds of rare plants.

Betty Alex, a fifth generation Texan, was raised in a small farming town in South Texas near Corpus Christi.  She graduated from Corpus Christi State University (now Texas A&M at Corpus Christi) with a B.S. in Wildlife Biology in 1977.  She worked for the U. S. Geological Survey for five years as a Sedimentologist and Biologist (her minor is in Geology). In 1980 she fulfilled a long desire to live and work in the Big Bend area of Texas by accepting a job at Big Bend National Park.  She worked in the Ranger Division for over a decade and then accepted the Geographic Information Specialist position doing GPS and computer mapping and spatial analysis.  After 22 years in that job, she retired in 2013. She now spends her time working on a project to organize several thousand photos from a Rare Plant project (2003-2007) and create a publicly accessible data base linked to the photos, working as a Volunteer In Parks for Big Bend National Park.  She also spends time being a grandmother and great-grandmother. 


Topic: Variation of seed banks among ecological states in the Chihuahuan Desert: implications for restoration

Presenter: Kirsten B. Romig. Contributors: D. James1, C. Maxwell1, B. Bestelmeyer1, J. Brown2, S. Salley1 1USDA-ARS, Jornada Experimental Range

Session Abstract:
State transitions involving the encroachment of shrubs and loss of herbaceous species are known to be highly persistent in the Chihuahuan Desert, even when disturbances are reduced and shrubs are removed. The existing seedbank in these soils is poorly documented and seed bank limitation might constrain the recovery of historical herbaceous communities.  From 2015 to 2017 we conducted a germinable seed bank study by collecting a total of 258 soil samples (each measuring 796 cm3) from randomly selected sites on 190,000 acres of the Jornada Experimental Range in Southern New Mexico.  Sites were stratified by ecological states within each of the ten ecological sites found on the range. Over a two-year period, these samples were provided ample water and monitored in greenhouse conditions. The soil yielded 12,777 seedlings from 159 species of vascular plants.  Variance partitioning and redundancy analysis showed that ecological site and state explains significantly more variability in germinable seeds by species than spatial structure alone (15.17% and 5.94% respectively; p = 0.001); however, a considerable amount of unexplained variability exists.  Seed banks in degraded states within ecological sites were generally limited with respect to desirable (native perennial) species with the exception of mesa dropseed grass (Sporobolus flexuosus) which occurred in 61.24% of the sites and 39.54% of the seedlings identified.  Additionally, mesa dropseed is more widely dispersed than other desirable grass species within ecological sites. Our results suggest that seed bank limitation may contribute to the persistent absence of key herbaceous species. The prevalence of mesa dropseed in the seed bank—even where it is not abundant aboveground—suggests that establishment limitations including soil surface degradation and herbivory need to be overcome to trigger mesa dropseed increase, but that seeding may not be necessary.

Kirsten B. Romig is a researcher for the Jornada Experimental Range in Las Cruces, New Mexico.  Her local moniker “Cowgirl Botanist” implicates her immersion and dedication to Range Science. 


Topic: The Amazing Variety of Cacti in the Chihuahuan Desert with a Focus on Texas

Presenter: Dr. Gertrud Konings

Session Abstract: The best known and most desired plants of the Chihuahuan Desert are its cacti. They are the mostly inconspicuous inhabitants of the dry environment and often disliked by ranchers. Their rare and short-lived flowers are awe-inspiring and stun the surprised observer by their beauty – a feature that may threaten their survival in the wild. This presentation will provide a brief photographic survey of the cactus varieties in the Texan part of the Chihuahuan Desert and touch on some conservation issues related to these plants.

Gertrud Konings-Dudin is a Professor of Biology, retired from the El Paso Community College.  She is a native German, graduated and received her Ph.D. in Biology from the Free University in Berlin, Germany. She is a passionate hiker in the Chihuahuan Desert and active locally in promoting the knowledge about the cacti in particular and their protection. Together with her husband, Ad Konings, she published in 2009 a book on the Cacti of Texas in their Natural Habitat.


Topic: Native Bee Floral Preference in the Desert Southwest

Presenter: Nikki Donegan. Contributor: Dr. Kevin Floyd

Session Abstract: Native bees are important pollinators, and many are experiencing population declines. Conservation organizations urge individuals to plant “bee-friendly” flowers but tend not to emphasize native plants.  Although assumed to be better for native bees, it is still unknown if native bees will prefer native plants when non-natives are available. We studied the preference of native bees for Chihuahuan Desert native plants at three locations at the University of Texas at El Paso. The locations had both native and non-native plants present. We surveyed the floral resources and bee visitations to flowers twice monthly from March 2018 to June 2019. We calculated the frequency that bees visited each flowering species. A total of 1558 visitations to 99 native and 34 non-native species of flowering plants were observed.  Seventy-two percent of the visitations were to native plants and twenty-eight percent to non-native plants. These visitations were proportional to the frequency of native and non-native plants at these locations, indicating lack of preference for native plants. This might be due to our survey methods, with all species of native bees combined into a single category. Species-specific preferences would not be detected with this method. We are currently working on identifying native bees to finer taxonomic levels, and on assessing which native plants are visited the most by native bees and if any non-native plants appear to be of particular importance. This information could help lead to optimal preservation efforts by increasing preferred floral resources available to native bees.

Nikki Donegan has been fascinated by flora and fauna for as long as she can remember.  She chose to pursue a Bachelor’s Degree in Environmental Science with a concentration in Biology when a professor from the El Paso Community College reminded her that she should do what she loves so she would continue to enjoy her education pursuit and her job afterwards.  Nikki will complete the requirements for her Bachelor’s Degree this December.  Nikki began working in the Bee Biodiversity laboratory after hearing about the opportunity in her Ecology class.  During her time in the laboratory, she earned third place for her dipteran research at the annual Geology Colloquium at the University of Texas at El Paso.  She is a STEMgrow and LSAMP scholar.  Nikki continues to help with the bee project while helping mentor incoming laboratory students.  


Topic: Lizard microhabitat preferences in the Organ Mountains and adjacent Chihuahuan Desert

Nina Dropcho

Session Abstract: The Chihuahuan Desert is one of the most biodiverse deserts in the world, and home to diverse lizard species. Land use, such as cattle grazing, alters the desert landscape and fragments the desert ecosystem, contributing to niche partitioning and reduced resources for lizard inhabitants. To understand how lizards adapt to a changing desert ecosystem, it is important to understand how the desert becomes fragmented into microhabitats characterized by different soil, flora and fauna. In Summer, 2019, lizards were surveyed in the Organ Mountains and neighboring Chihuahuan Desert. From designated trails, when a lizard was detected, its species and microhabitat were identified. Microhabitats were determined by measuring a 10m2 transect around the initial sighting of the lizard and then categorizing it as undisturbed desert, grazed desert, or mixed desert equally represented by flora typical of both undisturbed desert, such as cacti, and of grazed desert, such as creosote. Preliminary data show that Aspedoscelus spp., or whiptails, are found more frequently in grazed microhabitats (n=13, of 19 observations) than Phrynosomatidae lizards. Aspedoscelus tessalata, checkered whiptails, comprised half of the grazed microhabitat observations and accounted for 13 of the total 46 observations. These findings suggest that more frequent conservation monitoring of lizards in this region is warranted because species adapt differentially to changes in resources such as food, substrate and shelter, that result from land use. Also, research on niche partitioning by lizards in response to land use will help to elucidate the mechanisms which create new niches.

Nina Dropcho focuses her studies on evolutionary biology, incorporating principles of genetics, ecology, biodiversity, and conservation. She uses molecular biology techniques to look at the evolution between symbionts and their hosts, evolution that accompanies morphological variation, and animal-plant interactions. Although she is partial to lizards of the Desert Southwest, Nina has studied a variety of invertebrates, including beet leafhoppers, and both freshwater and marine snails. After receiving her B.S. in Biology from Metropolitan State University of Denver, Nina did an internship in a marine biology lab in Panamá with the Smithsonian Institution’s tropical branch, the Smithsonian Tropical Research Institute (STRI). She received her M.S. in Biology from New Mexico State University and is moving forward with her PhD research, also in Biology. When she is not spying on lizards around the Chihuahuan Desert, Nina enjoys traveling to places where she can go herp hiking in the jungle at night, and diving in the ocean, sometimes in the same day. 


Topic: Occupancy of Native Leopard Frogs in Response to Biotic and Abiotic Variable

Presenter: Lauren A. Samaniego

Session Abstract: Global amphibian declines have been recognized since the 1990’s and have since been attributed, but not limited to, climate change, habitat destruction, alteration, and fragmentation, disease, and invasive species. Amphibian species of the southwest United States are particularly susceptible to declines due to the presence of invasive Lithobates catesbeianus (American Bullfrog), Batrachochytrium dendrobatidis (chytrid fungus), variable hydrology, and an increasingly arid environment. We investigated perennial water sites located on the Ladder Ranch in Sierra County, just 75 miles northwest of Las Cruces, New Mexico to study responses of native ranids to biotic and abiotic variables. The Ladder Ranch is unique in that it is situated on the eastern most edge of federally endangered Lithobates chiricahuensis (Chiricahua Leopard Frog; CLF) and the western most edge of Lithobates blairi (Plains Leopard Frog; PLF) range, in New Mexico. Despite removal efforts, the Ladder Ranch also contains populations of American Bullfrog. We conducted occupancy surveys for the three frog species and collected water quality, habitat, and invertebrate community data. Results show no overlap between bullfrogs and the native frogs.  CLF was the most common frog species on the Ladder Ranch and presence was related to levels of phosphorus and terrestrial debris. Future analyses will compare multispecies occupancy with eDNA samples.

Ms. Lauren Samaniego received her Bachelor’s Degree from Texas State University and worked as a Middle School Science Teacher for 3 years. She has field experience working for the USDA Natural Resource Conservation Service (NRCS) in Arkansas during summer 2018. Lauren’s experience with NRCS has inspired and motivated her to pursue a career as an ecologist focusing on work with various stakeholders to build wildlife habitat and increase biodiversity. Her master’s thesis project has provided her the opportunity to investigate the impacts of invasive bullfrogs on congeneric and habitat sharing species on the Ladder Ranch in Sierra County, New Mexico.

Topic: Movement, Habitat Preference and Growth Rate of the Rough-footed Mud Turtle, Kinosternon hirtipes murrayi

Presenter: Jennifer Smith.  Contributors: Steven Platt, New Mexico State University, Wiebke Boeing, Wildlife Conservation Society Myanmar Program

Session Abstract: The Rough-footed mud turtle, Kinosternon hirtipes, is listed as Threatened with Texas Parks and Wildlife Department. The purpose of this on-going study is to investigate growth, sexual dimorphism, habitat preferences, movement and genetic diversity. Turtles were collected by traditional trapping methods and identifying notches were made on the marginal scutes. DNA was collected for genetic analysis. Transmitters were attached to identify movements. The growth model produced showed increased growth rate of juveniles until approximately 100 mm then a slowing trend with growth rate faster than other Kinosternids. A significant sexual dimorphism emerged with males significantly larger than females and the K. hirtipes murrayi in Texas larger than those found in Mexico. The telemetry study revealed a much greater affinity to water than other Kinosternids with movement during active season restricted to their aquatic habitats except for nesting. Genetic analysis with Geneious software and Fu and Li’s tests indicated a possible recent bottleneck. This information is invaluable when implementing a strategic management plan for this Threatened species.  


Topic: Citizen Science CSI: Better understanding the distribution of a newly described turtle shell disease condition through citizen observations

Presenter: Dr. Travis LaDuc.  Contributors: Drew R. Davis, University of Texas, Rio Grande Valley, and James L. Christiansen, University of Texas, Austin

Session Abstract: During the course of a 14-year study on the population demographics of Kinosternon flavescens in the Chihuahuan Desert of west Texas, we recognized the presence of a progressive and degenerative shell condition in our turtle population. This undescribed condition is mediated by the growth of blue-green algae that penetrate the pores of the carapacial keratin, eventually causing the keratin to slough off, exposing dermal bone. To assess whether this shell condition was unique to this west Texas population of turtles or whether this condition had a wider distribution across the range of the species, we reviewed all 350+ K. flavescens photos on the iNaturalist and HerpMapper web-based citizen science platforms. Although ~40% of the observations lacked the necessary dorsal photos, ~60% of the observations (including road-killed specimens) serendipitously documented the presence of this shell condition across the entire north-to-south distribution (Nebraska to northern Mexico) of K. flavescens over the last ten years. Combining data from these photographic vouchers with data from museum voucher specimens collected over the last century provides strong evidence for both the spatial and temporal persistence of this previously unrecognized shell condition across the geographic range of K. flavescens. These results demonstrate the ability to glean additional scientific utility from seemingly random and unique point observations. Additionally, these data stress the collective power of single observations made over time and space by both non-professionals and professionals alike.

Dr. Travis LaDuc, a native of Tucson, AZ, has been interested in reptiles since a young age, with a particular affinity for snakes. Travis first began his career in herpetology just out of high school working as a reptile keeper at the Arizona-Sonora Desert Museum. He received degrees from the University of Arizona, The University of Texas at El Paso, and The University of Texas at Austin. As the curator of herpetology at the Biodiversity Collections at The University of Texas at Austin, his job includes working with the preserved collection of 113,000 amphibian and reptile specimens, teaching natural history field courses at UT, and continuing his own research program. His research focuses on the biodiversity and natural history of Texas reptiles and amphibians, with current projects focused on the Spot-tailed Earless Lizard and the Yellow Mud Turtle.

Topic: Effects of Pan Trap Color on Bee Monitoring Efforts at the University of Texas at El Paso

Presenter: Bryanna Neria, Contributor: Kevin Floyd

Session Abstract: Bees are critical pollinators, and concern about possible population declines has led to increased calls for conservation. However, many native bee populations have not been sampled thoroughly enough to determine population status, particularly in our part of the Chihuahuan Desert, which is thought to have higher bee species richness than other ecosystems. Assessing bee populations requires collections, and a common method is pan trapping: colorful plastic bowls filled with soapy water. Previous studies in other ecosystems have shown that bees rely on visual cues such as color to select flowers and likely have distinct color preferences. The purpose of this study was to determine whether bee genera found at the University of Texas at El Paso preferentially select specific pan trap colors, with the overall goal of informing future sampling efforts. Alternating blue, yellow, and white pans were set out 10 times between March and September 2018. Bees collected in the pans were preserved, and are currently being identified to genus. Preliminary data shows that 937 bees were collected, representing five families and 18 genera. There were more bees collected in blue traps (39.9%) than in white (30.6%) or yellow (29.5%) pans. However, it does not appear to be a strong color preference, indicating that continued use of all three colors is necessary to most effectively sample the bee community with pan traps. Ongoing sampling at UTEP will provide baseline data on the populations of the bee community, allowing for better understanding of conservation needs.

Bryanna Neria is an undergraduate researcher at the University of Texas at El Paso, studying Biological Sciences with an expected graduation date of December 2019. She is passionate about entomological studies and intends to further pursue her education into graduate school. Bryanna strives to educate future generations of entomologists via the Bee Biodiversity Research Group (BBRG) and programs such as STEMGrow, an internship that introduced her to the field and which she continues to be a part of as a mentor.

The Remarkable Endemism of Moths in White Sands National Monument, Otero County, New Mexico

Presenter: Eric Metzler

Session Abstract:
White Sands National Monument at the northern edge of the Chihuahuan Desert in south central New Mexico protects 297.85 km2 (40%) of the world’s largest snow-white gypsum dune formation. The adaptations of Squamata, Rodentia, and Orthoptera prompted the National Park Service to call White Sands the Galapagos of North America. These animals are now surpassed by moths (Lepidoptera) as showing the greatest amount of speciation and adaptation in the dunes. The National Park Service invited Metzler to undertake a study of moths in White Sands National Monument. Along a transect 2.4 km long by 300 m wide on the southeastern edge of the dune field, more than 600 species of moths were recorded during the ten years field work, 2007-2017. Approximately 60 undescribed species of moths in seven families were recorded. The rate of endemism in moths in the Monument is approximately 9%. To date 15 of the new species were named. Species of normally dark-colored moths have white phenotypes in the dunes. Many plants in the dunes have haplotypes, chemical signatures, and associated microbes that are different from the same plant species outside the dunes. Lepidopteran larvae within the dunes are ingesting a different diet than larvae eating the same species of plants outside the dunes, and they pupate in a substrate with morphology and chemistry different than the soils outside the dunes. The species of Lepidoptera in the dunes exist in an ideal situation for evolution.

Eric Metzler graduated from Michigan State University in 1968. His first date with his wife-to-be, Pat, was black lighting for moths. At his retirement from the Ohio Department of Natural Resources, Ohio’s Governor appointed Eric as Ambassador of Natural Resources. In 2005, Eric was inducted in the Ohio Natural Resources Hall of Fame. Eric holds an Adjunct appointment, the Department of Entomology at Michigan State University. He is a research collaborator of the U.S. National Museum of Natural History, a research associate at the Museum of Southwestern Biology at UNM in Albuquerque, the McGuire Center for Lepidoptera and Biodiversity at the University of Florida, The Carnegie Museum of Natural History, and the Florida State Collection of Arthropods. He is conducting long term studies of moths at Carlsbad Caverns National Park and White Sands National Monument. He received the National Park Service’s Intermountain 2014 Regional Director’s Award for Natural Resource Research.

Topic: Aracnofauna (Arachnida: Aranae) of the Natural Protected Area: Médanos de Samalayuca, Chihuahua

Presenter: Irving David Chavez-Lara.  Contributor: Ana Gatica-Colima, Autonomous University of Ciudad Juárez.

Session Abstract: Across the Chihuahuan desert the spider group has been studied for nearly 90 years, in 1940 the first list of spiders in Texas was published (Vogel, 1970; Dean, 2016). On the other hand, works with spiders for the Mexican part of the Chihuahua Desert are focused on Cuatro Ciénegas, Coahuila and its surroundings. The Natural Protected Area “Médanos de Samalayuca” is situated in northern Chihuahua and is characterized by a sand dune formation Aklé type. Little information is available on spiders in that region. That’s why our main objective was to determine the richness of spider´s families in the NPA, according to different plant composition. The inventory was carried out in five different zones during three seasons: dry (June), wet (July-August) and post-humid (September-October) of 2017. Spiders were collected by hand, beating net and 10 pitfall traps in each zone per season. The spider fauna collected was preserved and identified (Ubick et al., 2018). A total of 606 spiders in 25 families were recorded. Thomisidae (17.5%), Salticidae (15.35%), Pholcidae (11.39%) and Theridiidae (10.4%) were the most abundant. The highest richness was in Zone III with 21 families and the dry season with 20. It must be considered that we need a total of 28 sample units to complete the spider inventory within the NPA: Médanos de Samalayuca according to the non-parametric estimators Jacknife 1 in the present research. Vegetal communities and seasonal differences play an important role in the family diversity of spiders in this deserts.

Irving David Chavez-Lara: Field technician with the activities of collector and spider identifier in the project “Multitaxonomic Inventory of Natural Protected Area: Médanos de Samalayuca, funded by CONABIO-CONANP with Dr. Ana Gatica-Colima as responsible (period 2017-2018). My undergrad studies in biology were at the Autonomous University of Ciudad Juárez (UACJ). I carried out my thesis “Aracnofauna (Arachnida: Araneae) of the Natural Protected Area: Médanos de Samalayuca, Chihuahua”. I´ve being a volunteer in in the assembly of mites and taxonomic determination of spiders at the Laboratory of Ecology and Animal Biodiversity (UACJ). Also, I made a research residency in biology, ecological, identification and assembly of the Acari (mites) group at National Autonomous University of Mexico (UNAM). Jiménez-Jiménez, M. L., C. Palacios-Cardiel and I. D. Chávez-Lara. XXXX. Nuevos registros de arañas (Arachnida: Araneae) para México y Listado faunístico de arañas de los Médanos Samalayuca, Chihuahua. Acta Zoológica Mexicana (Accepted).