ELUCIDATING RECRUITMENT STRESSORS FOR THE MARYLAND STATE ENDANGERED COMMON TERN (Sterna hirundo) THROUGH USE OF A MINIMALLY INVASIVE SURVEILLANCE SYSTEM

Abstract

In this thesis, I monitored two breeding colonies of the Maryland state endangered common tern (Sterna hirundo) using a surveillance system composed of video cameras and temperature loggers. This system was coupled with an in-depth image analysis of Landsat scenes to quantify island loss in the Chesapeake Bay and coastal bays of Maryland and Virginia from 1986 to 2016. Incubation duration was determined through analysis of both in-nest temperature and video footage. Incubation trends varied between colonies but an overall trend of nighttime desertion was observed on Skimmer Island as a result of predator presence. Island loss was documented in the region since 1986. Area of beach habitat, key for breeding populations of this species, increased in 1996 and 2011 as a result of sand accretion on coastal islands and the construction of Poplar Island. All other habitat types declined. This thesis is the first to document island loss in the Chesapeake Bay beyond 2011 and the first to quantify the impact of Poplar Island’s construction on the region. To promote future breeding of common terns in Maryland, resources must be allocated to create new habitat islands removed from the mainland and free of nesting predators. Existing islands must also be supplemented yearly with substrate to mitigate erosion from sea level rise.