Illustration © David Allen Sibley.
Learn more about these drawings.
Text © Kenn Kaufman, adapted from
Lives of North American Birds
Photo: Glenn Bartley/Vireo
Bay-breasted Warbler
Setophaga castanea
| Conservation status | Numbers may rise and fall, increasing after big outbreaks of spruce budworm or other insects. Could be vulnerable to loss of habitat on wintering grounds. |
|---|---|
| Family | Wood Warblers |
| Habitat | Woodlands, conifers in summer. Usually breeds in northern coniferous forest, in thick stands of spruce and fir. Where spruce is not found, will nest in deciduous or mixed second-growth woods of birches, maples, firs, and pines. In winter in the tropics, occurs in forest edge, second growth, and open woodland. |
Photo Gallery
Feeding Behavior
Appears more sluggish in foraging than do other Dendroica warblers feeding in the same spruce forests. Forages in and out along branches, mostly at mid-levels in trees. Rarely catches flying insects in mid-air. In winter in the tropics, joins mixed foraging flocks in the forest canopy.
Eggs
4-5, sometimes 3-7. Off-white, with brown or black marks at larger end. Incubated by female, 12-13 days. Female is fed on the nest by the male during incubation. Tends to lay more eggs in years of spruce budworm outbreaks, when food is abundant. Rarely parasitized by cowbirds. Young: Both parents feed the nestlings. Young leave the nest 11-12 days after hatching.
Young
Both parents feed the nestlings. Young leave the nest 11-12 days after hatching.
Diet
Mostly insects, berries. In breeding season, eats a variety of insects, including beetles, flies, moths, caterpillars, leafhoppers, and grasshoppers; also Virginia creeper berries and mulberries. May eat many spruce budworms when that insect is at epidemic numbers. In winter in the tropics, also eats many berries.
Nesting
Males may not arrive on breeding grounds until early June. Nest site is on a horizontal branch of a dense spruce, hemlock, birch, or other tree, 4-40' above the ground. Nest is a large, open cup, either loosely built or compact, made of grasses, lichens, roots, mosses, and protruding conifer twigs; lined with bark strips and hair.
How climate change could affect this bird's range
In the broadest and most detailed study of its kind, Audubon scientists have used hundreds of thousands of citizen-science observations and sophisticated climate models to predict how birds in the U.S. and Canada will react to climate change.
Read more: climate.audubon.org
Each map is a visual guide to where a particular bird species may find the climate conditions it needs to survive in the future. We call this the bird’s “climatic range.”
The colors indicate the season in which the bird may find suitable conditions— blue for winter, yellow for summer (breeding), and green for where they overlap (indicating their presence year-round).
The darker the shaded area, the more likely it is the bird species will find suitable climate conditions to survive there.
The outline of the approximate current range for each season remains fixed in each frame, allowing you to compare how the range will expand, contract, or shift in the future.
The first frame of the animation shows where the bird can find a suitable climate today (based on data from 2000). The next three frames predict where this bird’s suitable climate may shift in the future—one frame each for 2020, 2050, and 2080.
You can play or pause the animation with the orange button in the lower left, or select an individual frame to study by clicking on its year.
Bay-breasted Warbler In the News More News
Audubon Mural Project
Bay-breasted Warbler & Semipalmated Plover by FIFTY/FFTY
Location: 3300 Broadway, New York, NY 10031
