It measures approximately 23-25 centimeters in body length and weighs 40-57 grams.[2] It has a yellow beak and feet, silvery grey wings and white underbody and forehead. Its crown, nape, and eyeline are black. Juveniles are brown and white without the black cap.[3]
Nesting
It frequently nests alongside colonies of the large-billed tern (Phaetusa simplex) and the black skimmer (Rynchops niger).[4] The yellow-billed tern breeds from August to December on sand banks and island beaches. Non-breeding season habitats include coastal lagoons, river mouths, and rice fields.[5] Their nests consist of shallow scrapes in the sand. Most commonly a clutch contains 2 eggs, but the yellow-billed tern can lay anywhere between 1–4 eggs.[6] The incubation period is approximately 24 days. Nests are usually formed very close to each other.[4] Terns aggressively defend their nests from predators, and other species such as the sand-colored nighthawk (Chordeiles rupestris) have been known to nest among tern colonies to take advantage of this anti-predator behavior.[7]
Feeding
The yellow-billed tern forages during the day, mostly on small fish, shrimp, and insects.[2] It feeds by hovering and picking fish from surface waters.[3]
^ abGochfeld, M., Burger, J., Garcia, E.F.J. & Boesman, P. (2018). Yellow-billed Tern (Sternula superciliaris). Handbook of the Birds of the World Alive.
^ abRenaudier, A. and Claessens, O., 2014. Field identification of Least and Yellow-billed Terns: experience from French Guiana. Neotropical Birding, 15(1), pp.22-32.
^ abZarza, Rebecca; Cintra, Renato; Anciäes, Marina (December 2013). "Distribution, Abundance and Habitat Selection by Breeding Yellow-billed Terns (Sternula superciliaris), Large-Billed Terns (Phaetusa simplex) and Black Skimmers (Rynchops niger) in the Brazilian Amazon". Waterbirds. 36 (4): 470–481. doi:10.1675/063.036.0404. S2CID84904223.
