Fall migration begins in August but extends well into November, and birds continue to shift throughout the winter. An early spring migrant, yellowrumps are on the move in large flocks in early April, making the species the first warbler to move in numbers. The summer habitat is primarily coniferous forests. Yellowrumps take almost any kind of insect. In winter, yellowrumps feed mostly on berries, typically foraging in flocks, the size of which is partly dependent upon the food available.
Pairs stay close together throughout courtship and nest building.
The female does most of the nest construction, usually placing the nest on a horizontal limb of a conifer, from a few feet to as high as 50 feet above the ground. The female does most of the incubation of the 4-5 eggs and the brooding of the young. The male continues to feed the first brood while the female begins the second clutch.