April 2019 Bird of the Month

Bonaparte’s Gull on graceful wing.
© Andrew Liu 02
Sebastian Inlet State Park
Nikon D500 200-500 mm, ISO 400, 500mm, 1/1250, f/5.6.

Meet a real “snowbird,” that visits us for the winter months, beginning in December through March. With such a delicate curving black bill, black ear spot behind the eye, and graceful white wings and square tail edged in black, Bonaparte’s Gullscome in flocks. Very actively diving just above the water or dipping along our shores and coves, they capture small fish, invertebrates, and insects.

Breeding season begins in May, after they leave us for Canada and Alaska. To attract their mates, Bonaparte’s Gullsmolt their white head feathers, which are replaced by black feathers. Many birds have hormonal changes and breeding colors that lead to unusual eye-catching features to appeal, letting them know that it’s time, the season. Usually, to attract a particular mate, they exhibit specific behaviors (e.g. move towards them with a long call, then head toss). 

One of the few gulls that chooses to build their nests in trees, they select high locations in swampy, coniferous forests (tiaga) overlooking bogs, bays, and ponds so they can view any oncoming predators. If intruders come, the small colony of gulls easily spots them and raise the alarm. They come from different directions—diving, twisting, and turning—complaining together in their strident voices, distracting the intruder, thus keeping the nests undiscovered. 

In August, after breeding and raising their young, they molt again, losing the black head feathers before their journey south to us. While migrating and fishing along the ocean coasts, isn’t this mostly white bird harder for you and predators to see against the gray background waters or cloudy sky?

The Bonaparte’s Gullwas first described in 1815 with its Latin scientific name, but later given a common name after Prince Charles Lucien Bonaparte, nephew of Emperor Napoleon Bonaparte I. An ornithologist, Charles moved to America in 1822 from Italy to live with his new bride whose father lived in Philadelphia. He conceived of cataloging every bird species in the world. He started by publishing “American Ornithology, or History of the Birds of the United States” (4 vols., Philadelphia, 1825-’33), containing more than 100 new species he discovered by himself.

Juanita Baker, Coordinator
Florida Bird Photo of the Month
Pelican Island Audubon Society