In summer, Ruby-Crowned Kinglets are common in spruce-fir forests in the northwestern United States and across Canada. They also live in mixed woods, isolated trees in meadows, coniferous and deciduous forests, mountain-shrub habitat, and floodplain forests of oak, pine, spruce or aspen. These birds nest high in trees, and so prefer older, taller, and denser stands to younger ones. During migration and winter they are common in woods and thickets across most of the continent.Back to top
Ruby-Crowned Kinglets prey on spiders, pseudoscorpions, and many types of insects, including aphids, wasps, ants, and bark beetles. Kinglets usually forage in high tree foliage, hovering and pecking in order to glean insects from the surface of leaves and branches. These birds also eat a small amount of seeds and fruit, from poison-oak berries to the pulp of dogwood berries.Back to top
Ruby-Crowned Kinglets make their nests in trees, occasionally as high up as 100 feet. Females choose a nest site near the tree trunk or suspended from small twigs and branchlets. Because of the nest site's height and often remote location, not much is known about kinglet nesting habits. Their nest sites, chosen by the females, are protected and often hidden by overhanging foliage.
It takes Ruby-Crowned Kinglet females five days to build their nests, making trips every five minutes or so to gather materials: grasses, feathers, mosses, spiderwebs and cocoon silk for the outer structure, fine plant material and fur for the inner lining. When completed, the globe-shaped nest is 4 inches wide and 5-6 inches deep, and requires regular maintenance to keep it from disintegrating. Inside, it's about 3 inches across and 2 inches deep. The nest is elastic enough that it can stretch as the brood grows.
|Clutch Size:||5-12 eggs|
|Number of Broods:||1 brood|
|Egg Length:||0.5-0.6 in (1.3-1.5 cm)|
|Egg Width:||0.4-0.5 in (1-1.2 cm)|
|Incubation Period:||12-14 days|
|Nestling Period:||16-18 days|
|Egg Description:||Drab white spotted with red-brown around large end.|
|Condition at Hatching:||Helpless and completely naked, without any down.|
Breeding pairs of Ruby-Crowned Kinglets stay together for two months, until their chicks fledge. Ruby-Crowned Kinglets use their long, bubbly, and amazingly loud songs to establish territories; this is more energy efficient than chasing and less dangerous than fighting. They can be recognized by a constant flicking of their wings. Back to top
Ruby-crowned Kinglets are common and despite some sharp regional increases and declines, overall, their numbers were stable between 1966 and 2019, according to the North American Breeding Bird Survey. Partners in Flight estimates a global breeding population of 100 million and rates them 6 out of 20 on the Continental Concern Score, indicating a species of low conservation concern. Kinglets seem to handle human disturbance and habitat fragmentation fairly well, though logging and wildfire may reduce their numbers. Their wide use of habitats in winter helps them tolerate human disturbances.Back to top
Lutmerding, J. A. and A. S. Love. (2020). Longevity records of North American birds. Version 2020. Patuxent Wildlife Research Center, Bird Banding Laboratory 2020.
Partners in Flight. (2020). Avian Conservation Assessment Database, version 2020.
Sauer, J. R., D. K. Niven, J. E. Hines, D. J. Ziolkowski Jr., K. L. Pardieck, J. E. Fallon, and W. A. Link (2019). The North American Breeding Bird Survey, Results and Analysis 1966–2019. Version 2.07.2019. USGS Patuxent Wildlife Research Center, Laurel, MD, USA.
Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, NY, USA.
Swanson, David L., James L. Ingold and George E. Wallace. (2008). Ruby-crowned Kinglet (Regulus calendula), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.