Tells about geographic regions, aquatic biomes, coloration, mating, flight, food habits, status, and adaptations. Includes photographs and classification.

Tells about this Gull relative, including classification, size and appearance, status, threats, conservation, feeding and nesting behavior, distribution, and habitat.

Cornell Lab of Ornithology furnishes facts, description, similar species, sound, range, habitat, food, behavior, breeding, pictures, and distribution map.

WhatBird.com offers threat level, overview, range and habitat, sound clip, interesting facts, identification, behavior, and variations.

Classification and pictures accompany facts about appearance, diet, distribution, life cycle, habitat, and behavior.

Brief information from USGS covers appearance, habitat, coloration through life cycle, similar species, incubation, fledging, diet, and taxonomy.

Details identification tips, coloration differences, similar species, life history, map, ITIS taxonomy, and glossary.