The roseate tern (Sterna dougallii) is a beautiful seabird known for its delicate, pinkish plumage. This medium-sized tern breeds on islands along the northeast coast of North America, ranging from Nova Scotia down to the Caribbean. The roseate tern is listed as endangered in Canada and threatened in the United States due to population declines over the past few decades. So how many roseate terns are left in the wild?
Roseate Tern Population Trends
Historically, there may have been up to 100,000 breeding pairs of roseate terns in North America. However, the population crashed in the late 19th and early 20th centuries due to hunting for the millinery trade (feathers for hats) and egg collecting. By the 1930s, there were estimated to be less than 2,000 breeding pairs remaining. The passage of the Migratory Bird Treaty Act in 1918 afforded protection to the roseate tern and allowed some populations to recover to around 4,000-5,000 pairs by the 1960s.
However, in the late 1960s and 1970s, populations declined again due to disturbance from growing beach recreation and development on nesting islands. More recently, predation pressure from gulls, owls, and other predators has increased on many tern colonies. Despite conservation efforts, the total North American population has declined since 2000 and is currently estimated at less than 3,300 pairs.
Population by Region
Roseate terns nest in several distinct regional populations in North America:
Northeastern USA and Atlantic Canada
This is the stronghold of the species, supporting about 75% of the global population. Key nesting sites include Cape Cod (MA), Monomoy Island (MA), Bird Island (MA), Ram Island (ME), Stratton Island (ME), and Country Island (NB). The northeastern population is estimated at approximately 2,600 pairs.
Southeastern USA
Important nesting sites include the Dry Tortugas (FL) and Cape Lookout (NC). This population is very small at roughly 200-300 pairs.
Caribbean
Roseate terns nest sparsely throughout the Caribbean region, with about 200-500 pairs total. Key colonies are found on Cay Sal Bank (Bahamas), Buck Island Reef (USVI), Los Roques (Venezuela), and Saba.
Great Lakes
A small reintroduced population of roseate terns nests on man-made nesting platforms in Lake Michigan and Lake Huron. This population is less than 50 pairs but has been increasing in recent years.
Region | Population Estimate |
---|---|
Northeastern USA and Atlantic Canada | 2,600 pairs |
Southeastern USA | 200-300 pairs |
Caribbean | 200-500 pairs |
Great Lakes | Less than 50 pairs |
Threats to Roseate Terns
Several ongoing threats are putting pressure on roseate tern populations:
- Habitat loss – Coastal development destroys and degrades nesting habitat.
- Predation – Gulls, owls, foxes, and other predators eat eggs and chicks.
- Human disturbance – Beach recreation, ecotourism, and research activities can scare terns from nests.
- Climate change – Sea level rise and increased storm severity floods nests.
- Competition – Other tern species sometimes outcompete roseates for nest sites.
- Fishing bycatch – Roseate terns can get caught accidentally on longline fishing hooks.
Managing these threats is crucial for the recovery of the roseate tern population. Important conservation actions include protecting and restoring nesting habitat, controlling problematic predators, restricting human activity near colonies during breeding season, and working with the fishing industry to reduce bycatch.
Efforts to Save Roseate Terns
Many government agencies, conservation groups, and researchers are working to protect and expand the remaining roseate tern population, including:
- Canadian Wildlife Service
- U.S. Fish and Wildlife Service
- National Audubon Society
- Massachusetts Audubon Society
- Maine Coastal Islands National Wildlife Refuge
- Florida Keys National Marine Sanctuary
- University researchers
Some key conservation actions that have been taken include:
- Legally protecting nesting islands as wildlife refuges or sanctuaries.
- Restricting human access near colonies during breeding season.
- Posting tern warden staff on nesting islands to monitor birds.
- Controling predators like gulls, owls, and foxes.
- Creating artificial nesting platforms.
- Banding chicks to monitor populations.
- Public outreach and education programs.
Thanks to these efforts, some roseate tern colonies are now thriving. Continued intensive management will hopefully allow populations to grow and expand back into more of their historical range.
Outlook for the Future
The roseate tern has rebounded from the brink of extinction before, so there is hope it can recover again with dedication and persistence from conservation groups. However, the various threats the species faces makes for an uncertain future. Rising sea levels and increased storm activity due to climate change are difficult challenges to overcome.
Maintaining intensive management and habitat protection at the remaining colonies will be crucial. Continuing predator control, nesting platform programs, habitat restoration, bycatch mitigation, and reducing human disturbance will give the roseate tern the best chance at recovery. Expanding coordinated conservation efforts across state, provincial, and national borders will also benefit the species.
If current declining trends can be reversed, the North American population perhaps could grow to over 5,000 pairs again within the next few decades. For the roseate tern to be considered fully recovered, however, an order of magnitude increase to at least 10,000 pairs continent-wide may be necessary. This will be extremely challenging but remains a hopeful long-term goal if conservation needs can be met.
Conclusion
The current total North American population of the endangered roseate tern is likely less than 3,300 pairs and declining. Most of the remaining birds nest in the northeastern USA and Atlantic Canada, with smaller populations in the southeastern USA, Caribbean, and Great Lakes. Ongoing threats like habitat loss, predation, human disturbance, and climate change have caused the species to diminish from its historical numbers. Intensive conservation action has occurred in recent decades to protect colonies and stabilize populations. The outlook remains uncertain, but dedicated management of breeding sites and mitigation of threats may allow roseate tern numbers to slowly increase again. Recovery to at least 10,000 pairs is an ambitious but necessary goal to secure the species’ long-term survival. The resiliency the roseate tern has shown gives hope that it can bounce back once more if given the chance.