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Presenter: Sofia Marie Howland Harlow

Faculty Sponsor: Allison Roy

School: UMass Amherst

Research Area: Environmental Science and Sustainability

Session: Poster Session 5, 3:15 PM - 4:00 PM, Auditorium, A45

ABSTRACT

Blanding's Turtles (Emydoidea blandingii) live in fragmented populations scattered across New England, with their core range in the midwestern U.S. As an ectothermic species, Blanding’s Turtles are vulnerable to temperature irregularities and shifts in growing seasons. Our objective was to examine the effects of climatic variables on proportional annual growth rates in juveniles in the largest population in New England, located in north-central Massachusetts. We captured 68 unique juvenile Blanding’s Turtles during the spring and summer of 2025 using traps and opportunistic hand captures. Each individual was identified, measured, weighed, and photographed, which allowed us to age turtles by counting annuli (annual growth rings visible on the shell). We then used ImageJ software to measure distances between the annuli to calculate annual growth rates. We tested the effects of average summer temperature, total precipitation during the growing season, and number of summer days with maximum temperature > 35°C on proportional annual growth rates. We found that the number of days with maximum temperature > 35°C had a significant negative effect on growth rate, showing the potential negative impact of extreme weather conditions on growth. Precipitation did not have an effect, but average summer temperature had a significant positive effect on growth rate, suggesting that temperature has a stronger influence on growth than precipitation. Investigating these climate-growth relationships aids in understanding the cumulative environmental consequences of a vulnerable, slow-growing species.