here. Photo: Glenn Bartley/Vireo">

Read more about Bonaparte's Gull here. Photo: Glenn Bartley/Vireo

Bonaparte's Gull

Chroicocephalus philadelphia

This is the smallest gull usually seen over most of North America. Delicate in flight, it suggests a tern more than it does the larger gulls. It differs from large gulls in other ways as well: it seldom scavenges in garbage dumps, and it nests in trees, not on the ground. The name honors French zoologist Charles Lucien Bonaparte, a distant cousin of Napoleon.
Conservation status Numbers apparently stable. Has not benefitted from human activities as much as some gulls (e.g., does not feed at dumps). However, most of its nesting areas are remote from human disturbance.
Family Gulls and Terns
Habitat Ocean bays, lakes, muskeg. Breeds in edges of northern forest, where coniferous trees are near lakes or bogs. In migration and winter on many kinds of waters, including rivers and lakes inland, coastal estuaries and lagoons, sometimes well offshore on ocean. Often concentrates at sewage treatment ponds, probably to feed on the abundant insects there.
This is the smallest gull usually seen over most of North America. Delicate in flight, it suggests a tern more than it does the larger gulls. It differs from large gulls in other ways as well: it seldom scavenges in garbage dumps, and it nests in trees, not on the ground. The name honors French zoologist Charles Lucien Bonaparte, a distant cousin of Napoleon.
Photo Gallery
  • adult, breeding
  • immature (1st winter)
  • immature (1st winter)
  • adult, nonbreeding
  • adult, breeding
Feeding Behavior

Forages in flight by plunging into the water or dipping to the surface; also picks up items while swimming or wading. Often catches insects in the air. Unlike larger gulls, seldom scavenges at carrion or garbage dumps.


Eggs

3, sometimes 2 or 4. Olive to buff, blotched with brown. Incubation is probably by both parents, about 24 days. Young: Both parents feed young in nest. Development of young and age at first flight not well known. If intruders approach the nest, the adults perch on nearby treetops or fly about calling in protest.


Young

Both parents feed young in nest. Development of young and age at first flight not well known. If intruders approach the nest, the adults perch on nearby treetops or fly about calling in protest.

Diet

Insects, crustaceans, fish. Around inland nesting areas, apparently feeds mostly on insects. In coastal regions, where it spends most of the year, diet includes small fish (such as sand lance, herring, and pollock), crustaceans (especially euphausiid shrimp), insects, marine worms, and other invertebrates.


Nesting

Breeding behavior is not well known. Nests in isolated pairs or small colonies in sparse northern forest near water. Nest site is in coniferous tree, on horizontal branch usually 4-15' above ground, sometimes up to 20' or higher. Sometimes may build nest on ground. Nest is usually a rather small platform or open cup of sticks, lined with finer materials such as grass and moss.

Illustration © David Allen Sibley.
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Text © Kenn Kaufman, adapted from
Lives of North American Birds

Migration

Many birds from central Canada apparently move east or west toward nearest coast in fall. In winter, flocks may move around a lot in response to changing food supplies.

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Migration

Many birds from central Canada apparently move east or west toward nearest coast in fall. In winter, flocks may move around a lot in response to changing food supplies.

  • All Seasons - Common
  • All Seasons - Uncommon
  • Breeding - Common
  • Breeding - Uncommon
  • Winter - Common
  • Winter - Uncommon
  • Migration - Common
  • Migration - Uncommon
Songs and Calls
Rasping tee-ar; soft, nasal snarling note.
Audio © Lang Elliott, Bob McGuire, Kevin Colver, Martyn Stewart and others.
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