Ruby-crowned Kinglets are monogamous but form new pair bonds each breeding season. Their nests are usually 40 or more feet from the ground. Females build the nests, which are usually in conifers. ... During this time the male brings food to the female on the nest.

Are ruby-crowned kinglets aggressive?

Display C (Figure 4C) is extreme aggressive response and most spectacular Ruby-crowned Kinglet behavior.

Where do ruby-crowned kinglets live?

Ruby-crowned Kinglets breed across far northern North America as well as the western mountains. Most migrate to the southern and southwestern United States and Mexico for the winter—but some mountain populations in the West simply move to lower elevations during the cold months.