Warning This Web page has been archived on the Web.

Archived Content

Information identified as archived on the Web is for reference, research or recordkeeping purposes. It has not been altered or updated after the date of archiving. Web pages that are archived on the Web are not subject to the Government of Canada Web Standards, as per the Policy on Communications and Federal Identity.

Skip booklet index and go to page content

Roseate Tern (Sterna Dougallii)

Executive Summary

The Roseate Tern, Sterna dougallii, is listed as Endangered in Canada and the northeastern population is listed as Endangered in the United States. There are about 4000 pairs in the northeastern United States and 120-150 pairs in Atlantic Canada, mostly in one or two colonies. Its reproductive rate is limited by delayed maturity to age of first breeding (typically at age 3 [Spendelow et al. 2002]), small clutch size (typically two eggs for first clutches of older, experienced pairs, and one egg for first-time breeders), low annual adult survival for a seabird (83% [Spendelow et al. 1995] to 85% [Lebreton et al. 2003]) and relatively low survival to first breeding (usually 33-40%). Threats to its survival include habitat displacement; predation by Larus gulls and other predators (e.g., owls, night herons, and mink); possible market hunting on the wintering grounds; and, at least in some United States colonies, a shortage of males. The population’s restricted distribution makes it vulnerable to localized threats such as human development, catastrophic weather events such as hurricanes (Nisbet and Spendelow 1999; Lebreton et al. 2003), pollution and disease.

Since the publication of the first Canadian Recovery Plan for the Roseate Tern (Lock et al. 1993), new information on the species’ biology, its distribution in Canada, and methods for colony restoration have yielded novel approaches for its recovery. This new Recovery Strategy is completely revised to take advantage of this new information and to complement the recently updated United States Recovery Plan (USFWS 1998). It sets goals and objectives for Canada that will contribute to recovery of the Roseate Tern on both sides of the border and was prepared in response to the legislative requirements outlined in the Species at Risk Act (SARA) for the development of recovery strategies for Endangered species (Sections 37-46).

Together with the US Recovery Plan, this Canadian strategy aims not only to maintain and enhance breeding productivity, but also to restore the population’s range across broadly distributed colonies. Roseate Terns preferentially nest in larger colonies of other species of tern, so this goal requires the establishment of large, healthy colonies of other species within their range, especially Common Tern (S. hirundo) and Arctic Tern (S. paradisaea).

The long-term goal (10 years; present to 2015) of the strategy is to have no fewer than 150 pairs of Roseate Terns nesting in at least three colonies in Canada. Less than 5% of the northeastern North American population of Roseate Terns nests in Canada, therefore recovery of the entire population relies heavily on the recovery of the portion of the population nesting in the US. The US Recovery Plan (USFWS 1998) recommends reclassification to Threatened once the northeastern population reaches 5000 pairs, and that de-listing would be warranted once the species reaches historic population levels observed in the 1930’s (8500 pairs). In the short term (five years; present - 2010), the objectives are to:

  1. Maintain high numbers of breeding pairs at Country Island, Nova Scotia (>40 pairs) and The Brothers, NS (>80 pairs),
  2. Enhance productivity at managed colonies to high levels (i.e., 1.1 fledgling per pair; Nisbet and Spendelow 1999),
  3. Restore a broader distribution by establishing at least one more managed colony,
  4. Remove or reduce threats to Roseate Terns and their habitat, and
  5. Maintain small peripheral colonies of Roseate Terns nesting on Sable Island, NS and the Magdalen Islands, QC.

These objectives will be achieved primarily by:

  1. Monitoring population size, distribution, movement, and productivity
  2. Enhancing nesting habitat
  3. Managing additional colonies
  4. Identifying critical habitat
  5. Protecting habitat
  6. Identifying limiting factors at managed colonies
  7. Monitoring threats
  8. Improving decision making and planning