Endangered Roseate Terns Take a Turn for the Better

The United States' Roseate Tern population has reached its highest numbers since 1987, when it was listed as a federally Endangered species. According to the Massachusetts Division of Fisheries & Wildlife, the 2018 population estimate for United States Endangered Roseate Terns is 4,552 pairs. Fifty-one pairs were estimated for Canada.

Roseate Terns. Photo by Alcides Morales

Roseate Terns. Photo by Alcides Morales

The rebound is due in large part to successful habitat restoration and predatory gull management at the birds' three largest breeding colonies, located along the Atlantic coast in Massachusetts and New York. Living much of their lives on the open ocean, Roseate Terns spend only a few months on rocky islets where they nest. They winter off the northeast coast of South America and in the Caribbean.

Overall, this population estimate is great news, but Endangered Roseate Terns remain short of the recovery target goal of 5,000 pairs. And in recent decades, encouraging increases have been followed by reversals. Possible causes of the decline include climate change, sea level rise, competition for food from commercial fishing fleets, and largely unknown sources of mortality in the birds' tropical wintering range.

Adult and Juvenile Roseate Terns. Photo by Earnest Tse

Adult and juvenile Roseate Terns. Photo by Earnest Tse/Shutterstock

A new threat is also growing: Offshore wind energy development may provide a collision or displacement hazard to the terns and other seabirds. Such plans are being monitored by ABC and other conservation organization