Geology topics

Kevin J. Oxenrider

Publications and source records attributed to Kevin J. Oxenrider.

4 recordsLinked to original sources

USGS2025

Quantifying the relative importance of survival threats to a long-lived reptile using expert elicitation

Long-term survival of a conservation-reliant species requires understanding the impact of threats on population growth rate and the management actions that can help mitigate these threats. We used a threat assessment with expert-elicited estimates to determine the relative effect of each stage-specific threat on the population growth rate of the wood turtle Glyptemys insculpta . In addition, we offered potential management actions that could mitigate these threats and examined the relative cost and benefit of each. The experts responded that predators had the largest effect on hatchling and juvenile survival and that road mortality had the largest effect on adult survival. The population growth rate of the simulated turtle population increased the most when predators were removed from the system, though the population trajectory remained negative. Finally, we found that predator control had the lowest cost:benefit ratio of the proposed management actions. The process used in this analysis of expert elicitation combined with modeling that accounts for uncertainty proved to be a useful technique that is less expensive and labor intensive than empirical studies and quicker to implement, although it relies on sufficient empirical studies to inform expert responses. This process could be replicated for other species to inform species status assessments.

Endangered Species Research↗

USGS2023

Disinfection protocols for herpetofaunal pathogens

The spread of disease-causing pathogens is a major threat to amphibians and reptiles worldwide (Converse and Greene 2005; Picco et al. 2007; Picco and Collins 2008; St-Amour et al. 2008; O’Hanlon et al. 2018; Scheele et al. 2019). The World Organisation for Animal Health’s global list of notifiable animal diseases includes herpetofaunal diseases caused by infection with Ranavirus spp. (RV) and two chytrid fungi, Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal; WOAH 2023). Scientists began testing the efficacy of disinfection protocols even before human-assisted transmission of these pathogens was documented (Johnson et al. 2003; Johnson and Speare 2003; Brem et al. 2007; Bryan et al. 2009), and now guidance exists to determine the appropriate biosecurity measures as personal gear moves between habitats, construction equipment moves between project areas, and investigators handle multiple animals within a population (Phillot et al. 2010; Gray et al. 2017, 2018; Julian et al. 2020; Olson et al. 2021). People who are engaged in educational, recreational, commercial, or professional activities in wetlands and aquatic habitats play an important role in helping prevent the spread of pathogens and should know how and when to employ appropriate disinfecting procedures. In particular, working groups and regional chapters of Partners in Amphibian and Reptile Conservation (PARC) have developed a variety of educational materials on biosecurity and disinfection for a wide audience (e.g., PARC 2023). Herein, we provide the instructions for the disinfection of field equipment that were recently revised by the Emerging Disease Working Group of Northeast PARC (NEPARC 2022). The impetus for revision was to inform field personnel of the use of a stronger bleach concentration (ca. 10× stronger) that is needed for effectiveness against Bsal (Van Rooij et al. 2017). This is important for regions where Bsal is currently known to occur (e.g., central Europe) as well as regions where it is presumed absent but could arrive at any time (e.g., North America)

Herpetological Review↗

USGS2022

Evaluating the effect of expert elicitation techniques on population status assessment in the face of large uncertainty

Population projection models are important tools for conservation and management. They are often used for population status assessments, for threat analyses, and to predict the consequences of conservation actions. Although conservation decisions should be informed by science, critical decisions are often made with very little information to support decision-making. Conversely, postponing decisions until better information is available may reduce the benefit of a conservation decision. When empirical data are limited or lacking, expert elicitation can be used to supplement existing data and inform model parameter estimates. The use of rigorous techniques for expert elicitation that account for uncertainty can improve the quality of the expert elicited values and therefore the accuracy of the projection models. One recurring challenge for summarizing expert elicited values is how to aggregate them. Here, we illustrate a process for population status assessment using a combination of expert elicitation and data from the ecological literature. We discuss the importance of considering various aggregation techniques, and illustrate this process using matrix population models for the wood turtle ( Glyptemys insculpta ) to assist U.S. Fish and Wildlife Service decision-makers with their Species Status Assessment. We compare estimates of population growth using data from the ecological literature and four alternative aggregation techniques for the expert-elicited values. The estimate of population growth rate based on estimates from the literature (λ mean = 0.952, 95% CI: 0.87–1.01) could not be used to unequivocally reject the hypotheses of a rapidly declining population nor the hypothesis of a stable, or even slightly growing population, whereas our results for the expert-elicited estimates supported the hypothesis that the wood turtle population will decline over time. Our results showed that the aggregation techniques used had an impact on model estimates, suggesting that the choice of techniques should be carefully considered. We discuss the benefits and limitations associated with each method and their relevance to the population status assessment. We note a difference in the temporal scope or inference between the literature-based estimates that provided insights about historical changes, whereas the expert-based estimates were forward looking. Therefore, conducting an expert-elicitation in addition to using parameter estimates from the literature improved our understanding of our species of interest.

Journal of Environmental Management↗

USGS2022

Three steps to minimize wildlife disease transmission via construction equipment

Aquatic wildlife can be harmed by viruses, bacteria, fungi, and parasites introduced into wetlands. These infectious pathogens can survive in mud, soil, vegetation, and other debris that collect on the bodies and crevices of drivable equipment. Construction and habitat restoration projects can accidentally transport pathogens from a contaminated aquatic habitat into a healthy one. These three steps can help minimize the spread of pathogens to amphibians, reptiles, and fishes. The information provided in this fact sheet has been extracted from the publication, "Minimizing the Spread of Herpetofaunal Pathogens in Aquatic Habitats by Decontaminating Construction Equipment " (http://northeastparc.org/wp-content/uploads/2021/01/Julian-2020-Decontamination-for-Herps-for-large-equipment.pdf)

Report↗