Warbling Vireo
Vireo gilvus
The Warbling Vireo is a migrating bird, breeding across much of the United States and parts of Canada before departing south where they compress themselves for the winter into a much smaller area in Mexico and Central America. In appearance, it usually looks grayish on top and whitish, sometimes with a yellow wash, on the bottom including the throat. I usually find the pale white halo around its dark eye to be a great visual identifier. The photograph on the left gives the fullest picture of the bird, taken by the San Pablo Reservoir in California on May 5, 2020. The next two photographs show a vireo on its nest (in Tilden Regional Park, California), hung from thin tree branches and constructed mostly from plant matter and cobwebs knitted to hold it together. This one is about six feet off the ground. In the middle photograph taken on June 13, 2019 the parent is incubating the eggs (likely the female who does most of this work while the male gathers food for the family, but they do switch positions sometimes). Six days later on June 19, 2019, the parent is bringing a caterpillar to feed its new chicks. Caterpillars are one of the favorite foods of many bird species, both newborns and adults, so a habitat that produces them sustainably is quite important for the well-being of many bird species. (Click on images to see enlarged versions.)