North American field guide

Bonaparte's Gull

Chroicocephalus philadelphia

Explore this bird

Identification

Field notes

33 cm (13") Common. Summers in northern coniferous forests, winters on coasts, inshore waters, lakes, rivers, reservoirs. Pigeon-sized gull. Buoyant, tern-like flight shows flashy white wing tips. Black head, with broken white eye-ring; small black bill; white underparts and tail; gray mantle, with bold white wedge on upper wings, underside of wings pale; red legs.

Winter adult similar, but head white with small dark spot behind eye.

Song: tern-like "cheer".

Details in the field

Photo gallery

8 photos

Credit: Len Blumin

Credit: Larry Bond

Credit: Larry Bond

Credit: Maggie.Smith

Credit: Alan Vernon

Credit: Alan Vernon

Credit: Daniel Arndt

Credit: Laura Gooch

Watch and learn

Videos

1 video

Bonaparte's Gull feeding

Credit: Gary Shugart

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.

Bonaparte's Gull

2 rules

Rule 1 13 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 ?: Square or slightly notched at the end · Rounded at the end · Unknown
What colour was the BACK ?: White, or pale (grayish-white) · Gray, or blue-gray · Unknown
What colour was the BREAST ?: White, or pale (grayish-white) · Unknown
What colour was the THROAT ?: Brown, or chestnut (reddish-brown) · Gray, or blue-gray · Black, purple, or dark · Unknown
What colour was the BILL ?: Gray, or blue-gray · Black, purple, or dark · Unknown
What SHAPE was the BILL ?: Straight and thick · Hooked · Unknown
What LENGTH was the BILL ?: Short · Medium · Unknown
What colour were the EYES ?: Brown or blackish brown · Black or dark gray · Unknown
What was the predominant colour of the HEAD ?: Brown, or chestnut (reddish-brown) · 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 ?: Spring · Summer · Fall

result:543-bonaparte-s-gull:1:1 Source: 543 Bonaparte's Gull, row 1

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 ?: Square or slightly notched at the end · Rounded at the end · Unknown
What colour was the BACK ?: White, or pale (grayish-white) · Gray, or blue-gray · Unknown
What colour was the BREAST ?: 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 · Hooked · Unknown
What LENGTH was the BILL ?: Short · Medium · Unknown
What colour were the EYES ?: Brown or blackish brown · Black or dark gray · Unknown
What was the predominant colour of the HEAD ?: White, or pale (grayish-white) · 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

result:543-bonaparte-s-gull:2:1 Source: 543 Bonaparte's Gull, row 2