Introduction

Formerly breeding almost exclusively in the remote, boreal spruce-fir (Picea-Abies) forests of North America, the diminutive Golden-crowned Kinglet has been expanding its breeding range southward into spruce plantings in Pennsylvania, Illinois, Indiana, and Ohio. Nesting high in conifers, it lays its large clutch (5–11 eggs) in a cup-shaped nest built by both parents. Most pairs produce 2 broods a year, despite the short breeding season at northern latitudes. Much remains to be learned about the breeding biology of this species; only one study (northern Minnesota; Galati and Galati 1985, Galati 1991) has focused on this phase of its life history.

The winter habits of the Golden-crowned Kinglet are better known. It joins mixed-species flocks, wintering throughout its breeding range and south across the United States and into northeastern Mexico, in a variety of habitat types, both coniferous and deciduous. Apparently a hardier bird than the Ruby-crowned Kinglet (Regulus calendula), the Golden-crowned Kinglet winters farther north in areas where nighttime temperatures may fall to below –40°C. This species has escaped the influences of most human disturbances and may have benefited by reforestation of spruce in the eastern states.