Poster Session 5, 3:15 PM - 4:00 PM: Campus Center Auditorium [A43]

Prevalence of Scute Abnormalities in a Large Blanding’s Turtle Population in Central Massachusetts

Presenter: Sophie Eliza Bonazoli

Faculty Sponsor: Allison Roy

School: UMass Amherst

Research Area: Environmental Science and Sustainability

ABSTRACT

Turtles are among the most imperiled large tetrapod orders. A sign of developmental stress in turtles is the irregular formation of scutes, keratinous plates covering most turtles’ shells. Scute abnormalities are an example of fluctuating asymmetry. Embryos develop these abnormalities when signaling pathways that dictate scute formation are disrupted by environmental stressors, such as high temperature and low humidity, during incubation. Abnormalities include extra, missing, and deformed scutes. Fluctuating asymmetry is thought to decrease fitness, but no study has directly demonstrated this effect in turtles. Emydoidea blandingii (Blanding’s Turtles) are an imperiled species most common in the midwestern United States, with disjunct populations in New England and Nova Scotia. Our objective was to determine the prevalence of scute abnormalities in New England’s largest known population of Blanding’s Turtles, located in central Massachusetts. In 2025, we caught 316 unique individuals via traps and opportunistic hand capture. We measured and weighed each capture and approximated age by counting annuli. We recorded distinct markings, injuries, and congenital anomalies (i.e., deformed limbs, scute abnormalities). Overall, we captured 39 turtles (12.3% of total) with irregular scutes. The incidence of irregularity was significantly higher in females than males (Fisher’s Exact Test; p = 0.0184). Quantifying abnormalities by locus, we found that 94.2% of abnormalities were on the carapace and 5.76% were on the plastron. Just under half (49.0%) of carapacial abnormalities were vertebral, while 26.5% were costal and 24.5% were marginal. Tracking the prevalence of scute abnormalities may help gauge population health and inform local conservation efforts.