Date of Completion
Mark Urban, Isaac Ortega
Field of Study
Master of Science
Human activity can result in both local and global changes in the environment which in turn can affect other organisms and may result in population declines and loss of biodiversity. At the local scale, human activity often causes changes in habitat quality. For example, development and agriculture increase water turbidity which can influence wetland communities. At a global scale, carbon emissions are altering Earth’s climate, leading to increasing air temperatures. Using Wood Frogs, Lithobates sylvaticus, a wide-ranging, pond breeding amphibian, I sought to determine how sediment input affects larval amphibians and to assess how predicted loss of snow cover resulting from climate change may affect overwinter survival of adult wood frogs. Silt addition did not affect tadpole survival, and resulted in earlier metamorphosis (F1,30 = 5.111, p = 0.031) at a larger size (F1,30 = 36.244, p < 0.001), traits generally viewed as positive for population dynamics. Thus, sediment input may not be detrimental to wood frogs and may beneficially augment food resources. Using radio-telemetry and winter enclosures, I experimentally manipulated snow cover. I found that snow removal elevated risk of death for overwintering adults by up to 15.55 times and resulted in 45% decreases in estimated survival over the entire winter period. This suggests that loss of snow cover in the future could be detrimental to northeastern amphibians, but more research is warranted on this understudied life stage. Future studies incorporating more refined winter weather predictions or simulations are needed in order to better understand the true effect.
O'Connor, Jason H., "Manipulation of Larval and Winter Habitat Reveals Potential Effects of Urbanization and Climate Change on Wood Frogs in Connecticut" (2014). Master's Theses. 644.