This study analyzed threats to federally and State-listed endangered and threatened animal taxa in California, and how threats varied by taxa, habitat use, spatial extent, severity, geographical region, and endemic status using threat categories from the International Union for Conservation of Nature (IUCN) Red List Threats Classification Scheme and information from scientific literature and reports.

• Qin, G., Anderson, K.E., Cassady, A., Rodriguez, L., Syed, E., & Regan, H.M. (2024). An analysis of threats to endangered animal taxa in California’s freshwater systems. Aquatic Conservation: Marine and Freshwater Ecosystems, 34(1), e4057. https://doi.org/10.1002/aqc.4057

In September 2017, a total of 181 polar bears were observed near a bowhead whale (Balaena mysticetus) carcass on Wrangel Island. This gathering was the largest aggregation of polar bears ever recorded for that population. This research project sorted, labeled, and processed photographs of the polar bear aggregation taken by a professional photographer from a boat a day before initial ground-based observations were made. The objective was to use the photographs to evaluate characteristics of the polar bear aggregation including animal sex, age, reproductive composition (e.g., adult females that have first-year or second-year cubs), and body condition (i.e., fatness). 

I analyzed body condition data of Southeast Greenland polar bears. Since determining the mass of polar bears poses logistical and safety concerns, it is not always possible to measure. My analysis was focused on fitting growth curves (similar to the ones used for fish) for adult male and female polar bears. I used body length and width as independent variables in my nonlinear regressions to predict body mass at a given age.