Listing Status
- Federal Status: Threatened
- FL Status: Federally-designated Threatened
- FNAI Ranks: G4/S1 (Globally: Apparently Secure/State: Critically Imperiled)
- IUCN Status: LC (Least Concern)
Appearance
The roseate tern is a mid-sized tern that can reach a length of 15.7 inches (40 centimeters) with a wingspan of 23.6 inches (60 centimeters) (U.S. Fish & Wildlife Service 1999). This species has a black cap, gray upperparts, white underparts, and a white forked tail. Roseate terns have a thin black bill which becomes red during the breeding season (Florida Natural Areas Inventory 2001).
Behavior
The diet of the roseate tern primarily consists of small fish (ex. sand lance, hake, and herrings) and some invertebrates (National Audubon Society, n.d.).
Roseate terns breed and nest in colonies along with other terns (National Audubon Society, n.d.). They embark upon breeding grounds at the end of April (Spendelow 1995). During courtship, males will fly with a fish in its bill while letting out advertising calls to attract females. Males will also feed females as a courtship ritual (Gochfield et al. 1998). The availability of small fish seems to determine to approximate time the roseate tern nests. The Caribbean population (includes Florida’s population) lays up to two eggs in the middle part of May (National Audubon Society, n.d., Shealer 1992 as cited in Gochfield et al. 1998). The total incubation period for eggs is two to three weeks. Young roseate terns are able to fledge four weeks after hatching and are able to leave their parents around two months of age (Gochfield et al. 1998).
Habitat
The roseate tern nests in broken coral deposits, bare limestone, shell/sandy beaches, newly deposits of mudstone and rock, and rooftops. This species can be found from Nova Scotia, south to the Florida Keys, and on islands throughout the Caribbean. Roseate terns can also be found in Australia, Indonesia, southern Africa, northern Europe, the Azores, and the British Isles (Florida Natural Areas Inventory 2001).
Threats
The main threat to the roseate tern is human disturbance during nesting (U.S. Fish & Wildlife Service 1999). The collecting of eggs from roseate tern nests has caused the elimination of colonies in the Virgin Islands and other islands in the tropics (Gochfield et al. 1998). Increases in gull populations are a threat to the roseate tern as the gull’s aggressive nature can cause terns to desert their nests (National Audubon Society, n.d.). Hunting is a threat to the South American population as hunting occurs on their winter grounds (National Audubon Society, n.d.).
Conservation and Management
The roseate tern is protected by the U.S. Migratory Bird Treaty Act. It is also protected as a Threatened species by the Federal Endangered Species Act and as a Federally-designated Threatened species by Florida’s Endangered and Threatened Species Rule.
References
Florida Natural Areas Inventory. 2001. Field guide to the rare animals of Florida. http://www.fnai.org/FieldGuide/pdf/Sterna_dougallii.PDF
Gochfeld, Michael, Joanna Burger and Ian C. Nisbet. 1998. Roseate Tern (Sterna dougallii), The Birds of North America Online (A. Poole, Ed.).Ithaca: Cornell Lab of Ornithology Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna.html/species/370
National Audubon Society. (n.d.). Roseate Tern. Retrieved September 6, 2011, from Audubon: http://www.audubon.org/field-guide/bird/roseate-tern
Shealer, D. A. 1992. Behavioral and ecological factors affecting reproductive success in a threatened population of tropical Roseate Terns. Master's Thesis. Rutgers Univ., New\ Brunswick, NJ. as cited in Gochfeld, Michael, Joanna Burger and Ian C. Nisbet. 1998. Roseate Tern (Sterna dougallii), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna.html/species/370
Spendelow, J. A. (1995, March). Roseate Tern Fact Sheet. Retrieved September 6, 2011, from U.S. National Biological Service: http://www.mbr-pwrc.usgs.gov/mbr/tern2.htm
The Cornell Lab of Ornithology. (n.d.). Roseate tern. Retrieved September 6, 2011, from All About Birds: http://www.allaboutbirds.org/guide/roseate_tern/id
U.S. Fish & Wildlife Service. (1999, May). Roseate Tern. Retrieved September 6, 2011, from Multi-Species Recovery Plan for South Florida: http://www.fws.gov/verobeach/MSRPPDFs/RoseateTern.pdf