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Forster's Tern
(Sterna forsteri)
 German name(s): "Forster-Seeschwalbe"
Size: 33-36 cm; wing span: 64-70 cm
Weight: 160 g (average)
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Similar
species |
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Physical description |
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 Click here for a physical description
Forster's Terns are medium-sized terns. The two sexes look alike.
During the breeding
season they have a black cap with a curved lower boundary along
the sides of the hind neck. The sides of the head below the eyes,
the neck and the front are all-white. The back is light-grey,
with white front edges to the primary wing feathers. The panels
on the tips of the underwings are pale and inconspicuous, while
the upperwings are white.
When perched, the deeply forked tail extends beyond the tips of
the wings.
In eclipse
most of the head, especially the cap, turns white, leaving only
a rather small black patch behind each eye. Otherwise, except
for wear and tear, the overall morphology of the
plumage stays the
same.
The irises are black. The strong bill is red, with a black tip,
during the breeding
season and all-black in
eclipse.
The short legs and feet are red.
First-winter
Forster's Terns resemble
non-breeding
adults, but with dark centres to their primary coverts.
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Twitcher's tip |
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What distinguishes Forster's Terns from other, similar tern species
is the combination of white cap, red legs and black bill.
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Taxonomy, classification |
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See Forster's
Tern at Wikipedia  .
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Range, habitat, finding this species |
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Click here for information on habitat
and range
The overall distribution of this species can be assessed, and
specific locations where birds have been spotted can be found,
based on individual sighting reports submitted by birdwatchers to
ebird.org
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The global distribution of Forster's Tern is available
HERE
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Forster's Terns are a predominantly migratory North-American species.
There are only relatively small areas where the species is sedentary,
e.g. along parts of the North- to North-west coast of the Gulf of
Mexico and around the Chesapeake Bay.
Elsewhere, their breeding range basically encompasses parts of the
Great Lakes basin and westward from there, in the border region of
the US with Canada in the central North of the continent, to
southern Alberta, CA. There are more breeding areas in the central
and central western states of the US (for details see a field guide).
Their wintering range overlaps in small coastal areas with the
breeding range, extending southward along the West coast from
northern California and along the East coast from the Chesapeake
Bay, into broad near-coastal fringes of the southern US and also
Mexico, continuing into coastal central America. The winter
quarters also extend into the northern Caribbean up to Cuba, but
not to either Haiti or the Cayman Islands.
During the winter months Forster's Terns can stray eastward to the
Azores and to western Europe, but they do not reach Iceland or
Greenland.
In Europe Forster's Terns are found only as vagrants during
the winter months. They reach the British Isles, including
Ireland, and also the continental European coastline, from
western France to the West coast of Iberia.
Forster's Terns are "marsh terns", i.e. they breed in inland fresh
water habitats. When not breeding they disperse into (near-)coastal,
brackish or salt water habitats.
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Sightings |
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Click here for sighting information
J. Pires reports finding a Forster's Tern
in the Tejo estuary, Portugal, in February 2018.
All sighting and photographic information presented on this
page has kindly been contributed by J. Pires.
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Photos |
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ADULT |
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NON-BREEDING |
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Lateral view of a Forster's Tern in non-breeding
plumage
in flight
(photo courtesy of J. Pires)
[Tejo estuary, Portugal, February 2018]
Lateral view of a Forster's Tern in non-breeding
plumage
in flight
(photo courtesy of J. Pires)
[Tejo estuary, Portugal, February 2018]
Near-dorsal view of a Forster's Tern in non-breeding
plumage
in flight
(photo courtesy of J. Pires)
[Tejo estuary, Portugal, February 2018]
These pages are largely based on our own observations and those of our
contributors. The structure of these bird pages is explained HERE. For more salient facts on any bird species
please refer to a field guide.
Breeding
Nest
Eggs
Behaviour
Food
Call/s
