Driving back to Missouri, yesterday, I saw several large flocks of Franklin's gulls feeding above the fields of central Kansas. These small gulls nest in colonies on wetlands of the Northern Plains where they feed on a wide variety of plant and animal life, including seeds, insects, worms and mice. Like grebes, they build their nests on floating mats of vegetation which must be continually reinforced until the chicks have fledged.
During migrations across the Great Plains, they are generally encountered in large flocks, cavorting above fields and pastures to feast on clouds of flying insects, often following plows and harvesters that stir up their prey. En route, they also stage along the shores of lakes and reservoirs, joining migrant shorebirds, American white pelicans, white-faced ibis and a host of other gulls and terns.
By mid October they have usually moved south of the U.S., heading for wintering areas along the west coast of South America. Come April, their flocks reappear on the Southern Plains where they stop to rest and fuel on their way to breeding grounds in central Canada and the north-central U.S.