Mouette de Franklin

Mouette de taille moyenne avec des parties supérieures gris moyen. Le plumage nuptial présente une tête noire avec d'épais arcs oculaires blancs, de grandes taches blanches sur les extrémités des ailes noires, et un bec et des pattes rouge foncé. Les parties inférieures blanches sont souvent teintées de rose. Le plumage non nuptial présente une capuche noire partielle et un bec et des pattes sombres. Les juvéniles ont des parties supérieures plus brunes. Se reproduit autour des lacs et des marais dans les prairies du centre-nord de l'Amérique du Nord. Migre à travers le centre du continent vers et depuis les aires d'hivernage en Amérique du Sud, où elle est principalement trouvée sur la côte et en mer. Se rassemble en immenses groupes en migration et en hiver. Plus similaire à la Mouette atricille, qui est légèrement plus grande et plus élancée avec un bec plus long. La Mouette de Franklin présente des arcs oculaires plus épais et de plus grandes taches blanches sur les extrémités des ailes.

Identification

It breeds in central provinces of Canada and adjacent states of the northern United States. It is a migratory bird, wintering in Argentina, the Caribbean, Chile, and Peru.<p>The summer adult's body is white and its back and wings are much darker grey than all other gulls of similar size except the larger laughing gull. The wings have black tips with an adjacent white band. The bill and legs are red. The black hood of the breeding adult is mostly lost in winter.<p>Young birds are similar to the adult but have less developed hoods and lack the white wing band. They take three years to reach maturity.<p>Measurements:

Répartition et habitat

Although the bird is uncommon on the coasts of North America, it occurs as a rare vagrant to northwest Europe, south and west Africa, Australia and Japan, with a single record from Eilat, Israel, in 2011 (Smith 2011), and a single record from Larnaca, Cyprus, July 2006. At the beginning of 2017 has been observed also in Southern Romania, southeast Europe.

Aire de reproduction

NA : prairie marshes of w, n Alberta and ec Oregon to sw Manitoba (wc, ec Canada) and nw Minnesota

Aire hors reproduction

to w South Pacific coast from Ecuador and Galápagos to c Chile

Migration

Complete migrants

Comportement

They are omnivores like most gulls, and they will scavenge as well as seeking suitable small prey. In the spring, on rivers such as the Bow River large groups will float with the current, sipping the emerging insect hatch. The behaviour includes floating through a particular stretch and returning repeatedly to the same section.<p>The birds breed in colonies near prairie lakes with the nest constructed on the ground, or sometimes floating. The two or three eggs are incubated for about three weeks.