When filming at Audubon’s Beidler Forest the Making It Grow team used binoculars to spy on a female Prothonotary warbler sitting on her eggs in a small hole in a cypress knee. Only the female incubates the eggs, which hatch after fourteen days. Then both parents are involved in feeding them, flying back and forth all day long bringing them insects.
Ten or 11 days after hatching, the babies leave the nest, and the parents may have a second batch of young that same season. While we were at Beidler, there was a huge hatching of an insect important in this bird’s diet, mayflies. They were everywhere, landing on us and sitting on tree trunks by the dozen. Although not a large mouthful, their sheer abundance makes them an important part of this bird’s mostly insect diet. They also eat flies, spiders, caterpillars, adult Lepidopterans and snails.