The highest concentration of nesting birds can be found in the Bruce in May and June each year. About 20 species of warblers breed on "the Bruce," including the black-throated green, yellow, yellow-rumped, and Blackburnian warblers and the ubiquitous American redstart. They make their summer homes in the extensive wooded areas along the Peninsula. The annual Huron Fringe Birding Festival in May observes the spring migration. The endangered piping plover has made a comeback along the northern shores of Sauble Beach as well, and nest in restricted areas of the beach. These are well marked to prevent visitors overrunning the area and to reduce negative human effects. Migrating hawks also follow the Niagara Escarpment. Hawks travel during the day, and can be seen in the vicinity of Cabot Head in the open areas west of Dyers Bay, and near Tobermory, in April.