Bonaparte's Gull, Larus philadelphia


Bonaparte's Gull
Bonaparte's are handsome small gulls that become adults in two years.  Here are two in full breeding plumage: above, on the nesting grounds in Alaska in late May; below, a migrant already fully molted as it passes through California on May 1.


Bonaparte's Gull


Bonaparte's Gull
Above and below, two views of a breeding plumage bird in flight in Alaska.


Bonaparte's Gull


Bonaparte's Gull
A first-winter Bonaparte's, with the M-shaped pattern on the upper wings, and dark tips on the tail feathers.

Bonaparte's Gull
Bonaparte's Gulls are tern-like in appearance, flight, and feeding behavior, often fluttering over water daintily picking food off the surface; see above, and the three-image sequence below.

Bonaparte's Gull

Bonaparte's Gull

Bonaparte's Gull

Bonaparte's Gull
This ratty-looking bird is molting out of the brown juvenal plumage into the gray adult-type feathers of first winter in July.


Bonaparte's Gull
This October bird's dark bar between back and flanks is the inward slanting arm of the "M" pattern on the upperparts of first-winter Bonaparte's Gull, as shown further up the page. Below, a ventral flight view of another first-winter bird from the same flock.


Bonaparte's Gull


Bonaparte's Gull
An all-white tail, seen on the flying birds above and in the two pictures below, indicate adults in non-breeding plumage.


Bonaparte's Gull


Bonaparte's Gulls


Bonaparte's Gull
A standing bird in adult non-breeding plumage.