In a recent Perspective, Byrne (2023) emphasized that natural history museums “are essential hubs for research and education” but that their mission should be reimagined to focus on nonlethal collecting. We endorse many of the practices advocated by Byrne, including the storage of tissues, recordings, photos, and other data; embracing new technologies such as massively parallel DNA sequencing, μCT scanning, and stable isotope analysis; and large-scale digitization of collections and associated metadata. We also welcome the call to provide stable financial support to maintain and expand the infrastructure of existing collections. However, we do not support the call to use new technologies “to replace the need for whole animal bodies.” Byrne’s position overstates the potential of new technologies to replace specimen-based research and fails to acknowledge the importance of whole-organism–based research in building the foundations of modern biology and in continuing to promote new discoveries. Our goal is to underscore the tremendous value of ongoing, whole-organism specimen collection by highlighting some of the key scientific and societal gains that arise from this research.

Ranavirosis is a disease of high concern for amphibians due to widespread documentation of its lethal and sublethal impacts and its high transmission potential across populations and species. We investigated whether Spotted Salamander (Ambystoma maculatum) ranavirus prevalence and viral load were associated with habitat characteristics, genetic diversity, corticosterone levels, and body size. In 2015 and 2016, we sampled 34 recently created vernal pools in the Monongahela National Forest, West Virginia, USA. We collected tail clippings from 1,128 Spotted Salamander larvae and waterborne hormone samples from 436 of those larvae, along with eight environmental characteristics of the pools. Over the 2-yr period, we detected ranavirus in 62% of pools, with prevalence ranging from 0% to 63% (mean, 7.68%). Spotted Salamander size was positively correlated with ranavirus presence and viral load; however, we did not find associations between ranavirus prevalence or viral load and habitat characteristics, Spotted Salamander genetic diversity, relatedness, effective number of breeders, or corticosterone levels. The widespread occurrence of ranavirus in the vernal pools illustrates the potential for rapid natural introduction of the pathogen to created wetlands. Managers could consider monitoring local distributions of ranavirus before creation of new vernal pools to guide strategic placement of the wetlands to minimize occurrence and prevalence of this pathogen.

Cherax quadricarinatus (von Martens, 1868) is a large parastacid crayfish (Decapoda: Parastacidae) native to Australia and Papua New Guinea. Due to various factors, C. quadricarinatus is an emerging invasive species in an increasing number of regions across the world. Deleterious ecological effects of C. quadricarinatus introduction have been documented in many of these regions, and its spread has been monitored and restricted where possible. Previously, only a small, isolated population of C. quadricarinatus in southern California had been reported within the continental United States. Here, we report the collection of three adult C. quadricarinatus from Brownsville, Cameron County, Texas, the first record of this species in the state and only the second record for the continental United States. Given the connectivity of aquatic habitats in the area and the duration for which the population has likely been present, there is evidence that C. quadricarinatus is poised to invade subtropical watersheds of the southern United States. The ecological effects of C. quadricarinatus on aquatic ecosystems in the region are not yet fully understood, but further research is warranted to effectively mitigate negative impacts that may occur and to guide efforts to manage or eradicate these populations.

Turtle populations around the world are continually confronted with changing environments that affect their ecology and conservation status. Among freshwater turtles, population dynamics are thought to be mediated by complex yet often cryptic causes. One recent direction of focus in addressing these causes is the turtle-associated microbiota. In turtles, the gut-associated microbiota is of exceptional interest due to its continual association with host species under changing conditions. Diet-based fluctuations and changes in microbial diversity may correspond to varying external environments at both the individual and population level. Environmental responses are of particular interest due to the anthropogenic changes that may underlie them. Pollutants, disruption of climatic patterns, and habitat fragmentation all have the potential to affect turtle-associated microbiota and subsequent population and species conservation. To better understand potential human-induced changes, the diversity of turtle-associated microbiota over local spatial gradients must be better understood.We examined microbial community a- and b-diversity among 30 adult False Map Turtles (Graptemys pseudogeographica) at three sites within the lower Missouri River, United States. Our results indicate significant microbial community centroid differences among sites (b-diversity), which are likely mediated by various local environmental factors. Such factors will have to be carefully considered in any future attribution of anthropogenic determinants on turtle-associated microbiota as it relates to turtle population dynamics.

Madison JD, Butterfield MM, Davis DR, Kerby JL. 2022. Spatial dynamics of false map turtle (Graptemys pseudogeographica) bacterial microbiota in the lower Missouri River, United States. Journal of Herpetology 56:258–265. [PDF]

I recently revised and expanded (along with Travis J. LaDuc, Curator of Herpetology at The University of Texas at Austin) two chapters in the 71st Edition of the Texas Almanac: one on Texas wildlife and the other on threatened and endangered wildlife. We were able to greatly expand the chapter on Texas wildlife by revising and updating the previous mammal section and adding in new lists of fishes, amphibians, reptiles, and birds. In previous editions, these non-mammal sections were not included. The Texas Almanac is available for purchase through the Texas State Historical Association or through Amazon.

Davis DR, LaDuc TJ. 2022. Texas’ threatened and endangered wildlife. In Hatch R (ed.), Texas Almanac 2022–2023, 71st edition, p. 101. Texas State Historical Association, Austin, Texas.

Davis DR, LaDuc TJ. 2022. Texas wildlife. In Hatch R (ed.), Texas Almanac 2022–2023, 71st edition, p. 75–100. Texas State Historical Association, Austin, Texas.

The Black-spotted Newt (Notophthalmus meridionalis) is a chronically understudied salamander species, with many aspects of its natural history, ecology, and distribution poorly known. Previous studies using traditional methodologies have had limited success documenting N. meridionalis on the landscape, detecting individuals at 6% (7 of 114) and 1% (2 of 221) of sites surveyed. A novel environmental DNA (eDNA) assay was designed and implemented with the goals of assessing the current distribution of N. meridionalis across south Texas, USA, and better understanding the conditions for positive eDNA detections. We conducted eDNA sampling and traditional surveys at 80 sites throughout south Texas. Notophthalmus meridionalis was detected at 12 localities in total: four localities using eDNA surveys, four localities using traditional methods, and four localities with both methodologies. eDNA detections were obtained from five counties, including one where N. meridionalis has never been reported and another where N. meridionalis has not been observed since the 1930s. eDNA detections were obtained in all four seasons, generally following moderate to heavy rainfall events. Our results support the increased use of eDNA surveys to detect rare and cryptic amphibians and to better understand the current distribution of this imperiled species. 

Robinson PS, Davis DR, Collins SM, Kline RJ. 2022. Defining the current distribution of the imperiled black-spotted newt across south Texas, USA. Global Ecology and Conservation 36:e02131. [PDF]

Wildlife monitoring programs are instrumental for the assessment of species, habitat status, and for the management of factors affecting them. This is particularly important for species found in freshwater ecosystems, such as amphibians, as they have higher estimated extinction rates than terrestrial species. We developed and validated two species-specific environmental DNA (eDNA) protocols and applied them in the field to detect the Hazara Torrent Frog (Allopaa hazarensis) and Murree Hills Frog (Nanorana vicina). Additionally, we compared eDNA surveys with visual encounter surveys and estimated site occupancy. eDNA surveys resulted in higher occurrence probabilities for both A. hazarensis and N. vicina than for visual encounter surveys. Detection probability using eDNA was greater for both species, particularly for A. hazarensis. The top-ranked detection model for visual encounter surveys included effects of both year and temperature on both species, and the top-ranked occupancy model included effects of elevation and year. The top-ranked detection model for eDNA data was the null model, and the top-ranked occupancy model included effects of elevation, year, and wetland type. To our knowledge, this is the first time an eDNA survey has been used to monitor amphibian species in the Himalayan region.

Environmental DNA (eDNA) assays have become a major aspect of surveys for aquatic organisms in the past decade. These methods are highly sensitive, making them well-suited for monitoring rare and cryptic species. Current efforts to study the Rio Grande Siren in southern Texas have been hampered due to the cryptic nature of these aquatic salamanders. Arid conditions further add to the difficulty in studying this species, as many water bodies they inhabit are ephemeral, sometimes constraining sampling efforts to a short window after heavy rain. Additionally, sirens are known to cease activity and reside underground when ponds begin to dry or as water temperatures increase. Conventional sampling efforts require extensive trap-hours to be effective, which is not always possible within the required sampling window. This study presents the development of a novel eDNA assay technique for this elusive species using conventional PCR and Sanger sequencing and compares eDNA sampling results with simultaneous trapping at multiple sites to assess the relative effectiveness of the procedure. Rio Grande Siren detection via eDNA sampling was significantly higher at all sites compared to trapping, confirming the utility of this assay for species detection. This methodology gives promise for future work assessing the distribution and status of the Rio Grande Siren and has potential for use on other southern Texas amphibians. 

The Field Guide to the Amphibians and Reptiles of South Dakota (second edition) is now available! This newly-revised guide describes and illustrates all reptile and amphibian species in South Dakota in one reference. Color photos, updated distribution maps, and descriptions of life history and habitats help the reader identify 45 known and two possible species and understand the role these interesting animals play in nature. The second edition includes new illustrations and additional identification keys and reflects updated taxonomy and recent knowledge gained from university and community scientists. This field guide provides a glimpse into the lives of these intriguing members of South Dakota’s diverse natural heritage. Click here to purchase it ($20, shipped)