Breeding
adults
have red bill, which separates them from a number of white, black-capped
terns that are also found in the region. Like many other medium-sized,
capped white terns, juveniles and non-breeding adults have dark bills
and white foreheads. Outer primaries are partly black.
Size 32-36 cm (12 - 15 inches) total length.
Can
be confused with Forster's, Roseate and Arctic terns. Tail and tips of
folded wings are even in a sitting bird, whereas Roseate Tern has gray
outer primaries and a long, deeply-forked tail that extends far beyond
the wingtips when sitting. Bill of breeding birds (orange-red with dark
tip) is difficult to distinguish from that of breeding Roseate Tern.
Gray body of Common Tern in flight is distinct from the all-white
underbody and wing of Roseate Tern.
Adults
Known
to live to
26 years. Begin breeding at age of 3 years. Black caped, white tern.
Red legs and bill, bill with black tip. Winter plumage adults have
black bills and white foreheads.
Juveniles
Pronounced
carpal bar, dusty grey secondaries
Alternative
Names
French:
Sterne pierregarin
Spanish:
Gaviotin comun
Systematics
Three
subspecies
recognized: S. h hirundo
breeds throughout North America, Caribbean
basin, and eastern Eurasia. Winters in Gulf of Mexico, Caribbean, South
America, Africa and Indian Ocean. This is the palest, longest billed,
and shortest winged subspecies. Breeding adults bill red with black
tip, feet also red. Other races breed in western Eurasia.
Likely locations
Wintering
and
migrant birds are likely to show up anywhere though most migration is
far at sea. During the nesting season, birds are found in proximity of
breeding
colonies. Non-breeding individuals roost in breeding colonies of other
terns in the region.
In fact,
the West Indies region is an important maturation area where many
subadult birds remain for several years before reaching adulthood and
returning to northern breeding sites.
Distribution
Breeds
in
both
North America and Eurasia, winters at sea and coastal areas in the
tropics and subtropics. Breeding colonies primarily on Atlantic coast
and along inland rivers and lakes in Canada. Also nests in Bermuda and
on islands of Aruba, Curacao, Bonaire, and Venzuela. Typically
migrates far at sea.
Biology
At
sea
At sea
usually
in small to modest sized flocks often associated with gulls and other
tern species during migration and when wintering. Feeds on the wing by
diving to surface, plunge diving and contact dipping. Feeds on small
fish (under 150 mm) and sometimes on crustaceans and insects. Wintering
birds roost at night on shore.
At
the nest
Colonial,
nesting on ground. Nest is a scrape in sand
or other substrate. Generally 3 light brown, dark-splotched, eggs. Nest
material added during incubation. Nest in late spring. Incubation 21-23
days, fledging 22-29 days, parents continue to feed young until time
colony disperses.
Current Population
Country
BreedingSites
LowEstimate
HighEstimate
Comments
Bermuda
6
6
60
Bahamas
2
31
31
ProbablyROST
Turks&Caicos
2
200
210
ProbablyROST
Cuba
2
105
105
ProbablyROST
USVirginIslands
4
2
32
ProbablyROST
Anguilla
1
60
75
ProbablyROST
St.Bartholomew
2
50
55
ProbablyROST
Antigua&Barbuda
1
1
10
ProbablyROST
Guadeloupe
1
1
10
ProbablyROST
Martinique
1
1
10
ProbablyROST
Venezuela
7
116
170
Bonaire
3
5
24
Curacao
5
133
133
Aruba
1
40
40
Total
38
751
965
Inland
lakes and rivers 45,176 (Nisbet 2002)
Coastal
Canada 37,500 (Nisbet 2002) New
England 15,000 pr. (Brown and Nettleship 1984) North
and Middle Atlantic coast 29,000 pr (Buckley and Buckley 1984) South
Eastern US 2,247 (Clapp and Buckley 1984) Bermuda
25 pr. (Amos 1991) Netherlands
Antilles 200-300 pr. Voous (1983) Islands
off Venezuela ca 100 pr (LeCroy 1976) Total
129,473 pr. Kushlan et al. (2002) estimate 300,000 adults (150,000 pr.) Bahamas
a few (Buckley and Buckley 2000; Needs confirmation) West
Indies 50-100 pr. (Buckley and Buckley 2000; Needs confirmation)
Conservation Status
Not a
species of
conservation concern on a global level, but listed as endangered,
threatened or of special concern by states around the Great Lakes and
several Atlantic coastal states. Listed as Yellow (sensitive) in Nova
Scotia. The West Indian and Bermuda population is extremely small
(<100 pr) . For the total region there are probably fewer than
300
pair and these birds are in immediate conservation need.
Conservation Needs
Primary
need is confirmation of nesting as identification of birds in West
Indiean breeding colonies remains suspect. The Roseate Terns in the
region are more similar to Common Terns than Roseates in other
locations.
The few
small,
scattered colonies in the region need full protection from disturbance
and egging. Genetic studies in Bermuda of West Indian populations
are needed to show relationships with North American populations.
Possible
confusion with Roseate Terns makes some older reports suspect; surveys
of all current and historic breeding sites highly recommended. Migrant
Common Terns from North American breeding sites often appear in nesting
colonies of other terns, so care must be taken to confirm actual
nesting. Because of this, some older reports of breeding in the region
remain suspect.
Vegetation
management may be needed in some areas; these terns need open sites
with scattered vegetation for cover for chicks. Gull control should be
considered at colonies with near by nesting Laughing Gulls.
Relatively
rapid recovery of species along Atlantic coast after close of millinery
trade of the late 1800’s suggest that protection of this species in the
West Indies and on their wintering grounds would have positive results.
Photos
Selected References:
Amos, A.
1991. A guide to the birds of Bermuda. Warwick, Bermuda, privately
published. 206 pp.
Brown,
R. G. B. Brown and D. N. Nettleship. 1984. The seabirds of Northeastern
North America: their present status and conservation requirements. Pp.
85-100 in J. P. Croxall, P. G. Evans and R. W. Schreiber (eds.).
Status and Conservation of the World's Seabirds. ICBP Tech. Publ., No.
2. 778 p.
Buckley,
P. A. and F. G. Buckley. 1984. Seabirds of the North and Middle
Atlantic coast of the United States: their status and conservation. Pp.
101-133 in J. P. Croxall, P. G. Evans and R. W. Schreiber (eds.).
Status and Conservation of the World's Seabirds. ICBP Tech. Publ., No.
2. 778 p.
Buckley,
P. A. and F. G.Buckley. 2000. Breeding Common Terns in the Greater West
Indies: status and conservation priorities. Pp. 96-102 in E. A.
Schreiber and D. S. Lee (eds.) Status and Conservation of West Indian
Seabirds. Society of Caribbean Ornithology, Special Publication Number
1. 225 pp.
Clapp,
R. B. and P. A.Buckley. 1984. Status and conservation of seabirds in
the southeastern United States. Pp. 135-155 in J. P. Croxall, P. G.
Evans and R. W. Schreiber (eds). Status and Conservation of the World's
Seabirds. ICBP Tech. Publ., No. 2. 778 p.
LeCroy,
M. 1976. Birds observed from Los Roques, Venezuela. American Museum of
Natural History Novitates 2599: 1-30.
Nisbet,
I. C. T. 2002. Common Tern (Sterna hirundo). In The Birds of North
America, No. 618 (A. Poole and F. Gill, eds.). The Birds of North
America, Inc. Philadelphia, Pa.
Van
Halewyn, R. and R. Norton. 1984.The status and conservation of seabirds
in the Caribbean. Pp. 169-222 in J. P. Croxall, P. G. Evans and R. W.
Schreiber (eds). Status and Conservation of the World's Seabirds. ICBP
Tech. Publ., No. 2. 778 p.
Voous,
K. 1983. Birds of the Netherlands Antilles, 2nd ed. Curaco, De Walburg
Pers. 327 pp.
West
Indian Breeding Seabird Atlas by Will
Mackin and David Lee is licensed
under a Creative
Commons Attribution-Noncommercial-No Derivative Works 3.0 United States
License. Based on
work at www.wicbirds.net.
Permissions beyond the scope of this license may be available at www.wicbirds.net.
Suggested
Citation: Lee, D. S., W. A. Mackin. 2009. Common Tern. West Indian
Breeding Seabird Atlas
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Date accessed: ______.
