Chroicocephalus Philadelphia – Bonaparte’s Gull

Chroicocephalus Philadelphia - Bonaparte's Gull found in the US

The Bonaparte’s Gull, Chroicocephalus philadelphia is a gull species found primarily in northern North America. It is one of the smallest gull species. It has mostly white plumage with grey upper parts. During the breeding season, the hood of the Bonaparte’s gull turns slate-grey. The look of the sexes is comparable.

Quick Overview: Chroicocephalus Philadelphia – Bonaparte’s Gull
Body size: Around 12-14 in (30-36 cm) and a weight of 230 g (8.11 oz).
Main colors: Black, Gray, White, Red-Orange
Range: Throughout the United States
Migratory Bird: Yes
Best time of the year to see in the U.S.: March, April, May, September, October, November
Conservation Status: Least Concern

Bonaparte’s gull Description

This is a medium-sized gull with a black head and bill, gray back and wings, and white underparts and tail. In-flight, white outer primaries with black trailing margins can be seen. The legs are a bright red-orange color.

Chroicocephalus Philadelphia - Bonaparte's Gull found in the US
Chroicocephalus Philadelphia – Bonaparte’s Gull. Photo by: Kaaren Perry


These birds have a length of 12-14 in (30-36 cm) and a weight of 230 g (8.11 oz). Their wings could range from 33-36 in (84-91 cm).


The Bonaparte’s gull only nests for a short period of time, between late May and early July. During this time of year, they eat largely insects, although the rest of the year they eat small fish, krill, and crustaceans.


Bonaparte’s Gulls are small, sleek gulls that breed in the boreal forest and spend the winter on coastal beaches, lakes, and rivers further south. Adults have blackheads and red legs in the summer and a neat gray smear near the ear in the winter.


They are migratory, and the majority migrate east or west to coastal waters, including the Great Lakes. They fly gracefully, more like terns.

Chroicocephalus Philadelphia Scientific Classification

  • Kingdom: Animalia
  • Phylum: Chordata
  • Subphylum: Chelicerata
  • Class: Aves
  • Order: Passeriformes
  • Family: Laridae
  • Genus: Chroicocephalus
  • Species: Chroicocephalus philadelphia

Best time of the year to see

In the United States, the best time of year to see these birds are during the Spring season (March-May) and during the Autumn season (September – November).

Distribution of the Bonaparte’s gull in the USA

Breeds from western Alaska to Hudson Bay in subarctic North America. Winters along the Atlantic coast from Virginia to southern Missouri, then south into northern Mexico, and along the Pacific coast from Washington to central Mexico.

The Bonaparte’s gull can be found in the following states in the United States – Alabama, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, North Dakota, Ohio, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, West Virginia, Wisconsin, and Wyoming.

Chroicocephalus Philadelphia – Bonaparte’s Gull

Leave a Reply

Your email address will not be published. Required fields are marked *

The maximum upload file size: 15 MB. You can upload: image. Drop file here

Scroll to top