New York Natural Heritage Program
Forster's Tern
Sterna forsteri Nuttall, 1834
Birds

Threats [-]
Forster's Terns have been affected by habitat loss, hunting for feathers by the millinery trade, or hat making industry (1880s), and likely by environmental toxins (1960s-1970s) in parts of their range. Current threats in New York include human disturbance, flooding and habitat loss (Mcnicholl et al. 2001). Recreational boaters driving at high speeds or anchoring near salt marsh islands may disrupt terns from parental care of eggs and chicks leaving them vulnerable to predation. Mortality due to hypothermia has been reported when young chicks fled to the water in response to observers near nesting locations (Hall 1989, Fraser 1994a). Although Forster's Terns don't occur in large numbers in New York, populations may be threatened by habitat loss. A combination of factors may contribute to the dramatic declines of coastal salt marsh observed on Long Island over the last 50 years (Hartig 2002). Sea-level rise and increased storms and flooding due to global climate change is a threat to the salt marsh habitat that Forster's Terns require for nesting. Changes to hydrologic processes resulting from coastal development coupled with increases in sedimentary sulfide associated with human development are also believed to play primary roles in the decline of coastal salt marsh (Montalto and Steenhuis 2004, Kolker 2005).

Conservation Strategies and Management Practices [-]
Management for Forster's Terns requires both the protection of existing colonies to enable populations to perpetuate and grow, and the restoration and protection of habitat for terns to move into as populations expand or disturbed colonies need to relocate. Managing predators may be effective in certain circumstances where nest predation is high as has been effective for other tern species (Molina et al. 2010). 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. Posting educational signs just prior to the nesting season has been an effective method at limiting human disturbance to colonies of other tern species on beaches (Burger 1989).

Research Needs [-]
Forster's Terns have been studied less than other North American Tern species (Mcnicholl et al. 2001). More research is needed to determine their specific habitat requirements. Additionally, research into stopover locations and winter ecology is needed, especially to determine winter movements (Mcnicholl et al. 2001). Since there is much variability in nesting success between years and individuals may exhibit low site tenacity readily switching breeding colonies, long-term studies of reproductive success on marked birds are needed to determine trends in population numbers and productivity over time.