- Appearance: in summer (left) has black head, white body, grey wings with black tips, red feet, distinguishable
from laughing gull by black vs. red beak and white vs. grey underwings, in winter (top right), head fades to white with black spots behind eyes, legs fade to pink, wings lighter than laughing gull’s (right) and has white break at tips
- No significant difference between males and females
- Named after Charles Lucien Bonaparte, a nephew of Napoleon and leading ornithologist in the 1800s
- Length: 11-15 inches (about 1 foot)
- Wingspan: 30-32 inches (about 2.5 feet)
- Status: common, populations are increasing
- Still threatened by habitat loss, deforestation, water pollution
- Habitat:
- Range extends from Alaska and Canada throughout United States to northern Mexico, Cuba, and Caribbean Islands
- Breeds around lakes and marshes in boreal forest
- Winters along lakes, rivers, marshes, bays, and beaches along coasts
- Smallest gull in North America
- Diet:
- Small fish, crustaceans, snails, marine worms, insects
- Wades in water to catch sedentary (nonmobile) prey such as bivalves
- In summer, most of diet is insects caught midflight
- Flies over water and plucks prey off surface
- Occasionally dives into water to hunt
- Does not eat fish scraps, garbage, or carrion
- Migration:
- Migrates north/south across United States and along coastlines in flocks
- Adults migrate a few weeks earlier than juveniles
- Large flocks may take advantage of salmon fry (young) raised in fish hatcheries
- May also gather around sewage ponds to feed on insects
- In summer, breeds in Canada and Alaska
- Short arctic breeding season because ice only exposes open ocean for a few weeks, Bonaparte’s gulls nest from July-August, young grow quickly
- In winter, settles along east and wests U.S. coasts, Mexico, Cuba, Caribbean
- Unlike other gulls, may settle in inland forest during winter
- Arrives at breeding sites during spring ice melt and leaves before ice freezes in fall
- Commonly found around human settlements during winter on Long Island
- Flight speed unknown, but likely from 15-30 mph
- Nesting:
- Only gull in North America that regularly nests in trees (most gulls are ground nesters)
- Not much is known about this bird’s mating habits, may breed with same mate for multiple years
- Nest in pairs or small colonies of no more than a dozen, very territorial
- Nest is open cup of twigs, small branches, and bark, lined with mosses and lichens
- Usually 4-15 feet off ground, but can be higher
- Average brood is 1-4 green eggs with dark spots
- Male defends nest while female remains hidden in trees with eggs
- Call harshly, may even swoop and dive at intruder
- Within a day of hatching, chicks are able to stand, but do not leave nest until after about 1 week
- Both parents care for hatchlings
- “Young of the Year”
- During their first summer, young are brown to help blend in with the ground while they wander
- During their first winter, juveniles begin to molt into adult feathers, last feathers to molt are brown “M” stripes (highlighted with red) on wing and dark spots behind eye
- Reach maturity at 2 years old, develop seasonal breeding feathers during summer
- Oldest Bonaparte’s gull recorded was 9 years, but potentially lives about 18 years
