Voice: Song- high-pitched musical trill with a variable ending. Call-the common call is a dry check.
Yellow-rumped warblers, other wised known as butter butts, are one of the first migrant warblers to arrive in spring and the last to leave in fall. They occur in almost every habitat including woodlands, marshes, thickets, fields and ornamental landscapes. During the winter months yellow-rumped warblers are the most abundant warbler in North America. Their ability to eat fruit and digest waxes found in bay berries (Laurus nobilis) and wax myrtles (Myrica cerifera) allows it to winter farther north than other warbler. They are the only warbler that regularly over winters in Ohio.
Yellow-rumped warblers are opportunistic generalists when foraging. They will eat any plants or animals small enough to fit into their beak. Insects compose most of their diet. Their technique for capturing insects varies with individual birds. Some yellow-rumped warblers may swoop after prey in short spurts of flight or hover and glean insects and berries from the ground and vegetation including seaweed washed up at the beach. Other yellow-rumped warblers have also been observed skimming insect over the surface of rivers and oceans or picking them out of spider webs or manure piles. Male yellow-rumped warblers tend to forage higher in trees that females do.
Yellow-rumped warblers breed in dense, wet, coniferous forests in Northwest US, Alaska and Canada. Males arrive on the breeding grounds a few days before the females. Monogamous pairs form shortly after the females arrive. Females build nests, 4 to about 50 feet high up in conifer trees sometimes using material males carries to them. Yellow–rumped warblers prefer to make their nest in hemlock (Tsuga canadensis), spruce (Picea), white cedar (Thuja occidentalis), pine (Pinus), Douglas-fir (Pseudotsuga menziesii) or larch (Larix). Occasionally nests are built in a deciduous tree such as a maple (Acer), oak (Quercus), or birch (Betula). Nests are small, flat, cup shape made of twigs, grass, moss, and rootlets, lined with plant down and feathers that curve over the rim of the nest, partially covering the eggs. Nests take about 10 days to build, and is 3-4 inches across and about 2 inches tall when finished. Females incubate 4 to 5 eggs for 12 to 13 days. Males feed the female at the nest, and occasionally help incubate the eggs. Both male and females feed the young while they are in the nest. Young leave the nest 10 to 14 days after hatching. Males continue to feed the fledglings up to two weeks while the female may go off to starts a second set of young.
Yellow-rumped warblers are amongst the most common warblers in North America. Their generalized diet and habitat requirements have helped local populations increase or remain stable. However research has shown migrating yellow-rumped warblers, like other migrating birds, are frequently killed in collisions with lighted radio towers and buildings. Birds use a variety of different signals to navigate their route, including star pattern, topographic features, earth’s magnetic fields, and sunset. If any of these signals are disrupted or unclear such as lighted buildings or towers, it will disorientate and kill birds on their migration path. Light pollution is extremely simple and extremely difficult to remediate. Turning off lights is simple, getting companies or cities to agree to it can be challenging. Supporting local efforts to reduce city / town light pollution and minimizing personal use can be effective in helping birds on their migration journey.