Heard far more often than seen, the YBCH is a species that looks somewhere in between warbler and tanager, and only recently found itself in its own family, Icteriidae, after a long stay in the wood warbler family. Whistling, hooting, and clucking in what seems like a nonsensical manner, the YBCH can often be heard throughout the night in May and early June when it performs nocturnal singing as part of its courtship. During the day it can often be hard to find as it scavenges low in dense foliage in search of food. When it does perch in the open the bright yellow breast, white, belly, and gray topside create a striking appearance. Most common in the southern half of the state on desert streams with a willow component. Numbers are likely decreasing due to habitat loss, but the overall population appears somewhat stable at this time.
Habitat
In Utah generally associated with desert riparian dominated by willow thickets. Can also be found in dry overgrown pastures, and upland thickets along margins of woods. Breeds in very dense scrub and briary tangles, often along streams and at the edges of swamps or ponds.
Timing
The first individuals arrive in southern Utah in mid-April, with the number steadily increasing through May. By mid to late May most birds have arrived on breeding grounds, and reports are at their highest. This corresponds to when they are most active in their nocturnal singing as well. After breeding may be harder to detect since they stop singing, but numbers persist through the summer through early September. Uncommon at migrant traps in both spring and fall--migrants in the latter often linger into October, and typically represent northern breeders passing through.
Feeding
Searches for food in dense low tangles on a wide variety of insects, including moths, beetles, bugs, ants, bees, wasps, mayflies, grasshoppers, katydids, caterpillars, and praying mantises; also spiders. Up to half of the diet may be berries and wild fruit, including blackberries, elderberries, wild grapes, and others. Unlike wood warblers (former family), will hold its food with one foot while it feeds. Winter vagrants and migrants will also visit feeders in desperation.
Nesting
Male displays to the female by pointing bill up and swaying from side to side. During flight display, male flies up singing, hovers, then drops slowly with its wings flapping over its back and legs dangling loosely, then returns to perch. Occasionally nests in loose colonies. Nest built 1-8' above the ground, in well-concealed shrubs or vines. Large open cup nest is constructed by the female. The outer base of dead leaves, straw, and weeds provides support for a tightly woven inner nest of 3-4, up to 6 large, creamy white eggs, with brown spots at large end. Incubation lasts for 11 days and is solely performed by the female. After hatching, young are fed by both parents., before leaving the nest about 8 days after hatching. Normally 2 broods per year. YBCH is a regular victim of brood parasitism by Brown-headed Cowbirds.
Best Places to Find
In southern Utah, you can find YBCH on just about any desert stream where there is a major willow component. While this species does make it all the way through northern Utah, the best viewing sites are all in the south. Commonly found along the
Virgin River from Springdale to the town of Virgin. The
Dolores River above the confluence with the Colorado River and the
Green River for its entire lenght have perhaps some of the highest count numbers for this species. The
Fremont River from Capitol Reef to Hanksville, and
Lytle Ranch are all great locations to look during the height of the breeding season from May into early June.
In northern Utah
River Lane and
Diamond Fork Canyon in Utah County are typically fairly reliable, while
Birdsong Trail in Weber County has become a go-to location. During migration, this species can show up just about anywhere, and
Garr Ranch on Antelope Island gets several reports each year.