Mullinax Lab

Applied Spatial Wildlife Ecology

Common terns on poplar island


Current Student: Paul Marban

Other P.i.: Diann Prosser, USGS

Common terns (Sterna hirundo) are piscivorous waterbirds that nest along the Atlantic coast of North America.  The species is Maryland state endangered and currently nests only at the Paul S. Sarbanes Ecosystem Restoration Project at Poplar Island, Maryland in the Chesapeake Bay and a small breeding colony outside of Ocean City, along the Atlantic seaboard.  Extensive monitoring of the species has taken place at Poplar Island by USFWS and USGS Patuxent Wildlife Research Center.  Maryland DNR has monitored the Ocean City colony.  Previous nesting data for the species showed the species nesting throughout both the Chesapeake and coastal bays.  Determining the main threats to this species in Maryland and what has caused a decline in numbers is paramount for future research and management throughout the state.  The main threats to the species throughout its range include habitat degradation from development and recreational activities (Erwin 1980), disturbance at nesting and roosting sites (Nisbet 2002), and displacement and predation by herring (Larus argentatus) and great black backed gulls (Larus marinus) (HEGU and GBBG, respectively), great horned owl (Bubo virginianus) (GRHO), and red fox (Kress 1983, 1997, Burger and Gochfeld 1991).  The main goal of this project is to determine which of these stressors has had an effect on the population of common tern in Maryland and how these may be addressed in the future.


  1. Determine the causes for the common tern’s population decline in Maryland over time.

  2. Develop a minimally invasive surveillance system to monitor nesting colonies while decreasing researcher disturbance

  3. Utilize this system to aid in increasing hatching success estimates and resighting efforts on Poplar Island.