The 2019 summer had an exceptionally early arrival of Kolea in Hawaii. On July 16th Cheryl and Brian Allen of Mililani reported 3 plovers at Mililani Mauka Community Park. Others throughout Oahu also reported July returns. In previous years, the first returns were in early August.
Alaska had an exceptionally warm winter. Plover expert Wally Johnson speculates that the early returns signified that the birds either had an extra successful breeding year, due to the warmth, or an unproductive one, due to the warmth or perhaps some other factor. No one knows.
Typical summer tundra near Nome, Alaska. It’s unknown what effect global warming will have on shorebirds’ breeding cycles.