Status and Occurrence of Elegant Tern (Thalasseus elegans) in British Columbia
By Rick Toochin and Louis Haviland
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Introduction and Distribution
The Elegant Tern (Thalasseus elegans) is a medium sized species of tern found breeding along the west coast of Mexico in the Gulf of California (Burness et al. 1999). Incredibly 95% of the world’s population breeds on the island of Isla Rasa in the Sea of Cortez (Howell and Webb 2010). There is localized breeding along the Pacific Coast of the Baja to southern California (Howell and Webb 2010). The nesting season lasts from March to July with some post-breeding dispersal northward to southern California occurring from July to October (Howell and Webb 2010). The majority of the breeding population heads southward along the Pacific Coast of Mexico from July to October as birds head to their wintering grounds from Ecuador to Chile between the months of October to February (Clapp et al. 1993, Howell and Webb 2010). The Elegant Tern will wander further north of California in the fall in varying numbers depending on ocean temperatures and food supplies (Burness et al. 1999, Alderfer 2006). It appears the effects of El Nino can cause this species to move north during its post-breeding dispersal in massive numbers (Burness et al. 1999). In non El Nino years, the Elegant Tern can be all but absent north of California from Oregon to Washington State (Wahl et al. 2005). However, the Elegant Tern moves northward in the fall regularly enough that it is no longer a review species in Oregon by the Oregon Bird Records Committee (OFO 2012). There are well over 20 accepted state records and it appears the Elegant Tern will turn up almost annually in the State (OFO 2012). In Washington State, the Elegant Tern is also no longer a review species of the Washington Bird Records Committee with well over 20 accepted records (Wahl et al. 2005, WRBC 2013). The Elegant Tern is listed as an irregular, rare to locally common visitor in the summer to the outer coast and inland marine habitats (Wahl et al. 2005). Given the number of records for Oregon and Washington State, the post-breeding dispersal range of the Elegant Tern has Oregon and Washington State shown as part of its normal expected range in the fall (Burness et al. 1999).
In British Columbia, the Elegant Tern is a casually occurring species with over 25 Provincial records that are definitely linked to large El Nino events (Toochin et al. 2014, see Table 1). There are no records for Alaska (Gibson et al. 2013). The Elegant Tern is an accidental species in the rest of North America with a handful of records widely scattered from around the continent (Sibley 2000). There are 6 accepted records for Texas by the Texas Bird Records Committee (TBRC 2015) with one bird found at Corpus Christi on July 25, 1889 (American Ornithologist’s Union 1983) and at Lake Balmorhea, in west Texas, on December 25, 1985 (Williams 1985). There are 3 accepted records for Arizona (Stejskal and Witzeman 1988, Stejskal and Rosenberg 1990, AFO 2015). There are only a couple of widely scattered records from the East Coast of North America (Burness et al. 1999). The Elegant has amazingly been photographed in Europe and is listed as accidental in France (Lewington et al. 1992). In 1974, a single individual was found in a colony of Sandwich Terns (Thalasseus sandvicensis) at Arcachon, Gironde, France (Lewington et al. 1992). In 1984, 2 birds were present, both paired with Sandwich Terns (Lewington et al. 1992). In 1982 single birds were found in Ireland with one bird found at Carlingford Lough, Down District, Northern Ireland, and either the same bird or another individual was found at Ballymacoda, County Cork, Ireland (O’Sullivan and Smiddy 1988). A single individual was reported from Belgium in 1988 (Boesman 1992). There are other photographic records for Spain and Denmark (Welch 2007). There are further records of “orange-billed Terns” that fit the description of the Elegant Tern from other areas of Europe (Welch 2007). Of interest another Elegant Tern was found on Johnston Atoll, in the central Pacific Ocean in 1969 and incredibly this bird had been banded previously in 1966 at Western Salt Company, south San Diego Bay, in California (Amerson and Shelton 1976).
