New York Natural Heritage Program
Roseate Tern
Sterna dougallii Montagu, 1813
Birds

Threats [-]
Historically, Roseate Tern numbers were reduced by egging and the millinery trade before the passage of the Migratory Bird Treat Act (1918). Today Roseate Terns are threatened by habitat loss, human disturbance, increased predation rates from predators associated with human development, flooding from rising sea-levels and increased storms due to global climate change. The concentration of large numbers of Roseate Terns at few breeding locations in itself is a threat. Environmental factors such as storms and flooding or biological factors such as a low year of breeding due to chance or predation could produce years of low productivity. These effects in just a few colonies could affect the viability of the species in the state as well as in the entire northeastern U.S.

Conservation Strategies and Management Practices [-]
The establishment of other large, protected, successful colonies would benefit this species. Colony restoration by first removing gulls is controversial but has been successful at restoring colonies at two locations in Maine and one in Massachusetts (Gochfeld et al. 1998). Restoration of offshore sites that have greater protection from predators is essential to ensure long-term success (USFWS 1998). Predator control may be necessary at some sites where predation is high. Maintaining and protecting habitat at a number of suitable nesting locations is ideal even if some sites are temporarily unoccupied to allow colonies to relocate when disturbance occurs (McGowan and Corwin 2008).

Research Needs [-]
Annual productivity estimates on Great Gull Island seem to indicate good breeding success in that colony (Cormons, pers. comm.). Similar studies in other NY colonies, in addition to the population index counts that are conducted annually would be useful to determine trends in productivity. If breeding success is deemed to be low, then threats may be identified and management actions can be taken if needed. In order to ensure adult survival during the nonbreeding season, research on threats to the species on its wintering grounds should continue. Research is currently underway in Brazil (Hays et al. 1997, 1999). In addition, Brazilians from Aquasis in cooperation with the Great Gull Island Project are working to protect the species on the coast of Ceara in Northern Brazil (Hays 2009/2010). Until recently little was know of the behavior, feeding, and timing and locations of movements on the wintering grounds. However, initial studies currently are underway (Hays in prep.). Research is also needed to determine migratory routes and stopover locations and the relation of these movements to fish availability (Gochfeld et al. 1998). Puerto Rico was recently identified as a stopover location when Gabriel Lugo photographed banded Roseate Terns during migration (Hays et al. 2010).