One of this year’s Student Presentation Awards goes to Abigail Reid, a high school student in the Science Research Program at Pawling High School, NY. Abigail presented her research as an oral presentation in a Methodology & Techniques session of the joint AFO-WOS meeting in Chattanooga, TN, USA. Below is a contributed post from Abigail on her research:
Implications for using singed feathers in determining geographic origin with wildlife forensics approaches
Despite the increasing popularity of renewable energy, utility-scale renewable energy facilities can adversely affect wildlife. During the past two decades, stable hydrogen isotope (δ2H) values have emerged an important tool for assessing the geographic origin of mobile organisms, such as birds. This tool has become invaluable for addressing questions about bird movement and connectivity across the annual cycle, including applied questions of direct conservation and management relevance. Stable hydrogen isotope analysis of feathers has been previously used as a conservation forensics technique to infer the geographic origin and impact of wind-energy facilities on bird populations. However, at concentrating solar power plants, avian mortality often results from solar-flux effects, which also causes singeing to the feathers. Thus, it is essential to understand how heat and singeing may affect the interpretation of δ2H values in feathers and subsequent geographic assignments for birds killed at solar energy facilities.
In the lab, we first heated feathers from two passerine species (Sturnella neglecta and Eremophila alpestris) at known heat loads of 200°C, 250°C, and 300°C for 60 seconds. Second, we obtained paired singed and unsigned feathers from three different passerine species (Haemorhous mexicanus, Setophaga petechial, and Setophaga coronata) that were found dead at a concentrating solar-energy facility in California. We used a traditional ANOVA to evaluate the effect of known heat loads in the lab and field-singeing on feather δ2H values.
The heating trials in the lab resulted in visible singeing but minimal change to δ2H values of the feathers at 200 and 250°C. At 300°C, severe charring occurred and was accompanied by a significant decline in δ2H values of 26.5‰. Previous studies demonstrated a difference of approximately 15‰ would produce a different likelihood of origin map, and so a 26.5‰ decrease would substantially change geographic origin assessment in feathers heated at 300°C. For the field-singed feathers, there was no indication that heating in the solar flux field significantly altered the δ2H values of the samples.
Therefore, our results suggest that highly singed or charred feathers should be avoided when selecting feathers for δ2H-based assessment of geographic origin. Limited to moderate singeing does not appear to dramatically alter δ2H values or feather morphology, and we conclude that moderately singed feathers can be used in geographic origin analysis if unsinged feathers are not available. These results help to expand the application of δ2H values as a tool for studying bird movement, thus aiding conservation and management.
- Abigail Reid – Pawling High School, NY
- Hannah B. Vander Zanden – Dept. of Biology, University of Florida; USGS Forest & Rangeland Ecosystem Science Center – Boise
- Todd Katzner – USGS Forest & Rangeland Ecosystem Science Center – Boise
- David M. Nelson – Appalachian Laboratory, University of Maryland Center for Environmental Science