Swallows begin massing near the lagoons, taking advantage of the summer's insect hatch. From their nesting colonies along the Gulf of Mexico, ibises, herons, and egrets arrive at Hornsby, part of the late summer dispersal which may take them as far north as southern Canada. Most if the locally-nesting birds fall silent, as the molt their old feathers in preparation for either migration or the coming winter. September sees the peak movement of southbound landbirds. Migrant hawks begin appearing in numbers.
More ducks arrive, and most of the shorebirds depart for wintering grounds far to the south.
Some of the permanently resident birds, having completed their molt, begin a fall song period. By October, most of the southbound shorebirds and landbirds have left. Wintering landbirds such as sparrows begin arriving in numbers. Coots arrive in numbers. Hawk migration reaches its peak.