- Golden-winged Warblers have suffered one of the steepest population declines of any songbird species in the past 45 years, but the Cornell Lab and partners in the Golden-winged Warbler Working Group have a conservation plan to stop the decline and grow the population 50% by the year 2050.
- Minnesota has the highest remaining density of Golden-winged Warblers, with about half the global population.
- Recent work with radio-transmitters has expanded our knowledge of Golden-winged Warbler habitat. The birds breed in shrubby, tangled thickets and other “early successional” habitats. But after the chicks fledge, the families move to mature forest habitats to continue raising their young.
- Golden-winged Warblers often hybridize with the closely related Blue-winged Warbler. The Blue-winged Warbler has been expanding its range, and hybridization has been one element in the sharp decline of Golden-winged Warblers.
- Hybrids tend to develop into one of two distinctive plumages, which early naturalists at first thought were separate species: “Brewster’s Warbler” (which looks like a Blue-winged Warbler with a white chest), and “Lawrence’s Warbler” (which looks like an all-yellow Golden-winged Warbler).
- Hybrids do not sing intermediate songs but sing either normal Blue-winged Warbler or Golden-winged Warbler songs. Some birds sing both. Occasionally pure-looking parental types sing the “wrong” song.
- Golden-winged parents may use trickery to protect their young from predators. Adults feeding nestlings have been observed repeatedly carrying food down other plant stems away from the next, possibly as a decoy, when they detected humans nearby.
- The oldest known Golden-winged Warbler was at least 7 years old when it was caught and released at a banding station in Minnesota.
Golden-winged Warblers breed in tangled, shrubby habitats such as regenerating clearcuts, wet thickets, tamarack bogs, and aspen or willow stands. They tend to occur in wetland habitats more often than the closely related (and competitive) Blue-winged Warbler. Recent radio-tracking studies have discovered that Golden-winged Warblers move into mature forests immediately after fledging. This means that mosaics of shrubby, open areas (for nesting) and mature forest habitats (which offer cover for fledglings from like predators like hawks) are important landscape features. Historically periodic natural disturbances would create this patchy habitat—wildfires or flooding from beaver dams created a patchwork of shrubby openings amid a largely forested landscape. The early 20th century was good to Golden-winged Warblers, as settlers cleared forest openings for settlement and farming. But as the century progressed, many of those cleared areas grew back into forests, and humans prevented natural disturbances from opening up new pockets of nesting areas. Since the 1960s, Golden-winged Warbler habitat has decreased by an estimated 22 percent in the Great Lakes region and 43 percent in the northern Appalachians. On their wintering grounds, Golden-winged Warblers live in semiopen woodlands, as well as bird-friendly coffee farms under a forest canopy.
Food items include caterpillars, moths and other insects, and spiders. Leafroller caterpillars appear to be an important food source. Golden-winged Warblers feed among the foliage by probing with their sharp bills into rolled-up leaves to find hidden prey. They only rarely catch insects on the wing.
- Clutch Size
- 3–6 eggs
- Number of Broods
- 1 broods
- Egg Length
- 0.6–0.7 in
- Egg Width
- 0.4–0.6 in
- Incubation Period
- 10–12 days
- Nestling Period
- 8–9 days
- Egg Description
- Pale pink or pale cream, with fine streaks or small blotches
- Condition at Hatching
- Helpless and mostly naked; juvenile flight feathers begin to emerge on sixth day.
The female builds the nest, usually on the ground, over the course of 1–3 days. She often places the nest at the base of a plant such as goldenrod or blackberry, using the a tall, thick plant stem as a support (adults often land on this when arriving at the nest). She makes a base from up to 30 leaves and then adds grapevine or arrowwood bark and other long strips of plant material. Finished nests measure about 3.5 to 6 inches across and 1 to 2.5 inches deep. Females are very sensitive to disturbance and may abandon nests even after the first eggs have been laid.
Females probably select the nest site, which is typically on the ground in a grassy opening or along the shaded edge of a field near a forest border. The nest is typically well concealed by overhead grasses and leafy material.
Golden-winged Warblers often forage among brushy and shrubby areas, where they hop along branches, carefully inspecting the leaves for prey, and sometimes dangling off the edges of branches like a chickadee. Male golden-wings are extremely bold and vocal during the 3 to 4 weeks at the start of their breeding season, prone to prolonged and exuberant bouts of singing. They also engage in a variety of postures and behavior in order to demarcate their territory, including chasing and flying past rival males, spreading their tails in face-offs, and sometimes actually physically fighting. Males also chase after females during courtship, raise their crowns and flick their tails when approaching a potential mate, and perform flight displays with slow, deep wingbeats. But after territories are established and mates are selected, they become very secretive during nesting and raising young. Golden-wing males are mostly monogamous, though there are a few reports of them having multiple mates.