Forster's Tern

Sterna forsteri

Explore this bird

Identification

Field notes

36-38 cm (14-15") Common. Marshes, lakes, coast. Pigeon-sized bird with a deeply forked tail. White head with a black cap; orange-red bill with a black tip; white underparts; pale gray mantle, with frosty wing tips; gray white-edged tail; orange legs. Similar Common Tern has dusky wing tips and shorter legs and bill.

Winter adult similar to summer, but black cap replaced by narrow black eye patch.

Song: harsh nasal "za-a-ap" and high-pitched "kyarr".

Details in the field

Photo gallery

4 photos

Beach, Huntington Beach, CA, US - May 11, 2008

Credit: Chuq Von Rospach

Charleston Terrace, Palo Alto, CA, US - July 5, 2010

Credit: Chuq Von Rospach

Non-breeding - Navy Yard, DC, US - September 9, 2006

Credit: DC Nature

Adult, non-breeding. Swans Cove Pool, Chincoteague National Wildlife Refuge, Assateague Island, Virginia, USA - October 2010

Credit: Dave Govoni

Watch and learn

Videos

2 videos

Forster's Tern Preening

Credit: Stephen Ingraham

Forster's Tern 3 (Panasonic GH2 + 100-300mm)

Credit: MackM48

Where it lives

Distribution maps

Source legend · original intervals

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Unshaded in source · does not imply absence

Generic and winter maps may use different intervals.

Bird Advisor Identification rules 1 variant 2 rules

These are the observation paths the Bird Advisor can use to identify this species. Each rule is an alternative match.

Forster's Tern

2 rules

Rule 1 13 criteria confidence 5

What colour were the LEGS or FEET ?: Orange, buff (orange-yellow), or tan · Red, or pink · Rufous (dull-red or rust-colored) · Unknown
What SHAPE was the TAIL ?: Forked · Unknown
What colour was the BACK ?: Gray, or blue-gray · Unknown
What colour was the BREAST ?: White, or pale (grayish-white) · Unknown
What colour was the THROAT ?: White, or pale (grayish-white) · Unknown
What colour was the BILL ?: Orange, buff (orange-yellow), or tan · Red, or pink · Rufous (dull-red or rust-colored) · Unknown
What SHAPE was the BILL ?: Straight and thick · Unknown
What LENGTH was the BILL ?: Short · Medium · Long · Unknown
What colour were the EYES ?: Brown or blackish brown · Black or dark gray · Unknown
What colour was the TOP of HEAD ?: White, or pale (grayish-white) · Black, purple, or dark · Unknown
How BIG was the bird ?: Pigeon-sized · Crow-sized
What TYPE of bird was seen ?: Gull-like, or a Seabird
WHEN was the bird seen ?: Spring · Summer

result:555-forster-s-tern:1:1 Source: 555 Forster's Tern, row 1

Rule 2 13 criteria confidence 5

What colour were the LEGS or FEET ?: Orange, buff (orange-yellow), or tan · Red, or pink · Rufous (dull-red or rust-colored) · Unknown
What SHAPE was the TAIL ?: Forked · Unknown
What colour was the BACK ?: Gray, or blue-gray · Unknown
What colour was the BREAST ?: White, or pale (grayish-white) · Unknown
What colour was the THROAT ?: White, or pale (grayish-white) · Unknown
What colour was the BILL ?: Gray, or blue-gray · Black, purple, or dark · Unknown
What SHAPE was the BILL ?: Straight and thick · Unknown
What LENGTH was the BILL ?: Short · Medium · Long · Unknown
What colour were the EYES ?: Brown or blackish brown · Black or dark gray · Unknown
What colour was the TOP of HEAD ?: White, or pale (grayish-white) · Gray, or blue-gray · Unknown
How BIG was the bird ?: Pigeon-sized · Crow-sized
What TYPE of bird was seen ?: Gull-like, or a Seabird
WHEN was the bird seen ?: Fall · Winter

result:555-forster-s-tern:2:1 Source: 555 Forster's Tern, row 2