Bonaparte’s Gull is a small, graceful gull that visits Arizona primarily during migration and in winter. Unlike many larger, more raucous gulls, Bonaparte’s Gulls are dainty and buoyant, often likened to terns because of their delicate build and agile flight. Adults in breeding plumage display a striking black hood, a thin black bill, pale gray upperparts, and white underparts, while nonbreeding birds lose the hood and show a dark spot behind the eye. Their wingtips are marked with distinctive black and white patterns that help with identification in flight.
In Arizona, Bonaparte’s Gulls are considered uncommon but regular migrants and winter visitors, mainly seen from late fall through early spring. They frequent large reservoirs, lakes, and rivers, particularly in the central and southern parts of the state. Locations such as Lake Pleasant, Roosevelt Lake, and the Colorado River corridor can host flocks, especially during migration peaks. Occasionally, individuals turn up at wastewater treatment ponds or even urban parks with sizable bodies of water.
Feeding mainly on small fish, aquatic invertebrates, and insects, Bonaparte’s Gulls often forage by dipping to the water’s surface or making short, graceful plunges. They also pick insects off the water, a behavior that sets them apart from many other gulls that rely more on scavenging. Although their breeding grounds are far to the north in boreal forest wetlands of Alaska and Canada, their seasonal movements bring them into Arizona.
