Bonaparte's Gull
Chroicocephalus philadelphia
Bonaparte's gull is a gull found mainly in northern North America. At 28 to 38 cm in length, it is one of the smallest species of gull. Its plumage is mainly white with grey upperparts. During breeding season, Bonaparte's gull gains a slaty-black hood. The sexes are similar in appearance. Source
Where it is now
In the last 8 weeks this bird was recorded 1,306 times across 23 areas (each area is a 5 degree square).
See the Bonaparte's Gull on the live map
Arrival dates
The week it was first heard regularly in each region, after at least six weeks away. Dates differ from south to north, so a region has a range.
| Region | First arrival | Last arrival | Typical peak | Areas |
|---|---|---|---|---|
| North America | 19 January 2026 | 10 August 2026 | 26 January 2026 | 2 |
Figures are effort corrected and come from automatic sound identification, which makes mistakes. How this is measured and how it compares with human observers.