North American field guide
Common Tern
Sterna hirundo
Identification
Field notes
33-41 cm (13-16") Common. Lakes, rivers, bays, beaches, islands, coasts. Graceful, pigeon-sized bird with a deeply forked tail. White head with a black cap; red bill usually has black tip; white underparts; pale gray mantle, darkest at wing tips: red legs. Similar Arctic Tern has an all red bill; grayish underneath with translucent primaries.
Winter adult similar, but black cap is incomplete; bill and feet blackish.
A dark phase, a Siberian subspecies, has black feet and bill can be seen in western Alaska.
Song: "KEEarr", also "kik-kik-kik".
Details in the field
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Pair Common Terns
Credit: Terry CooperFISKTÄRNA Common Tern (Sterna hirundo) Klipp - 284
Credit: AROSFILMWhere 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 2 variants · 3 rules
These are the observation paths the Bird Advisor can use to identify this species. Each rule is an alternative match.
Common Tern
2 rulesRule 1 12 criteria · confidence 4
- 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 · Black, purple, or dark · Unknown
- What colour was the BREAST ?
- White, or pale (grayish-white) · Unknown
- What colour was the THROAT ?
- White, or pale (grayish-white) · 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 ?
- 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 · Fall
Rule 2 12 criteria · confidence 4
- 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 · Black, purple, or dark · Unknown
- What colour was the BREAST ?
- White, or pale (grayish-white) · Unknown
- What colour was the THROAT ?
- White, or pale (grayish-white) · 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 · 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 ?
- Winter
Common Tern (Siberian Dark Phase)
1 ruleRule 1 14 criteria · confidence 1
- What colour were the LEGS or FEET ?
- Black, purple, or dark · Unknown
- What SHAPE was the TAIL ?
- Forked · Unknown
- What colour was the BACK ?
- Gray, or blue-gray · Black, purple, or dark · Unknown
- What colour was the BREAST ?
- White, or pale (grayish-white) · Gray, or blue-gray · Unknown
- What colour was the THROAT ?
- White, or pale (grayish-white) · Gray, or blue-gray · 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 ?
- 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 · Fall
- WHERE was the bird seen ?
- Northwestern Canada or United States