Sterna caspia
Caspian tern

Key Characteristics

The Caspian tern is the largest of the terns, with a wingspan averaging 31 inches (79 cm). Its size, stout red bill, and lack of a deeply forked tail distinguishes it from other white terns found in the state. Its black cap, large red bill, and tern-like habit of flying slowly with its bill pointed downward separates it from the gulls. The low harsh call of the Caspian tern sounds similar to "karrr" or "kraa-ah" and is given frequently while in flight. The orange feet of immature birds distinguish them from fall-plumaged adults which have black feet.

Status and Rank

  • State Status: T - Threatened (legally protected)
  • State Rank: S2 - Imperiled
  • Global Rank: G5 - Secure

Occurrences

County NameNumber of OccurrencesYear Last Observed
Alcona11982
Alpena21999
Arenac12009
Bay12009
Charlevoix31987
Cheboygan11998
Delta22002
Mackinac42007
County Distribution Map for [SNAME]

Updated 05/08/2013. Information is summarized from MNFI's database of rare species and community occurrences. Data may not reflect true distribution since much of the state has not been thoroughly surveyed.

Habitat

Caspian terns typically nest on islands to avoid many terrestrial predators.

Natural Community Types

Management

Conservation efforts should concentrate on the protection of nest sites from human disturbance. Terns using contaminated sites for nesting should be provided with alternative breeding sites with uncontaminated substrate. Colonies should be monitored on a regular basis to document changes in numbers of breeding pairs, reproductive success, and impacts of toxins.

Active Period

Migration from third week of April to third week of May

Nesting from third week of May to first week of August

Migration from third week of August to third week of September

Survey Methods

Surveys of nesting colonies may conducted by foot, boat, or aircraft. In any case, efforts should be made to minimize the disturbance to the nesting birds as much as possible.

Page Citation

Michigan Natural Features Inventory. 2007. Rare Species Explorer (Web Application). Available online at http://mnfi.anr.msu.edu/explorer [Accessed May 18, 2013]

More Information

See MNFI Species Abstract

References

Survey References

Technical References