Delaney Costante

The earth is currently in the midst of the sixth mass extinction; unlike the previous five, humans are the driving factor behind species’ losses. In the U.S., the primary means of mitigating biodiversity loss is the Endangered Species Act (ESA); its purpose is to protect and recover imperiled species and the ecosystems upon which they depend. The aim of this project is to identify temporal trends and taxonomic differences in the threats which may impact imperiled species at the time of their listing. We developed a database of threats using the Federal Register final rule listing documents of every U.S. species (n = 1560) protected by the ESA between 1975-2019. Using this database, we identified 114 threat categories grouped into six broad categories: habitat modification, overutilization, pollution, species-species interactions, environmental stochasticity, and demographic stochasticity. Based on our previous work, we hypothesize that threats relating to habitat modification, interactions with invasive species (species-species interactions), and random environmental events (environmental stochasticity) will be the most prevalent across all taxonomic groups. We also hypothesize that the number of threats impacting species at the time of their listing will increase over time. This research will allow conservation practitioners to evaluate the effectiveness of conservation strategies. In addition, our research will provide crucial information to demonstrate how the recent changes to the ESA may be detrimental to the purpose of the ESA.

Delaney Costante is a first-year M.S. student in the Biology Department at William & Mary. She graduated from Millersville University with a B.S. in Biology, including concentrations in marine biology, environmental biology, and animal behavior. She is currently working in the lab of Dr. Leu to identify temporal and taxonomic trends among the threats which impact imperiled species.