By Daniel Shworan

Introduction

Most easily recognizable by its flaming yellow “crown” on the top of its head, the Golden-crowned Kinglet (Regulus satrapa) is a foliage-gleaner that spans most of Northern America (All About Birds, n.d.). Barely larger than a hummingbird (Length: 4 inches), this territorial little fellow isn’t afraid to keep competitors away. When excited, this bird commonly fluffs up his golden yellow crest, serving multiple purposes that contribute to its fitness (Audubon, n.d.). Read along to learn all about many of the quirks that make this bird unique and some research that involves this “lit” bird.

Identification

What it looks like:

The Golden-crowned Kinglet is slightly larger than a hummingbird and has a rounder body with shorter wings. Its bill size is small and stout, and its tail is thin. It has a dull grayish olive plumage color on its back, a paler white color on its belly, and very recognizable color formation on its head. Surrounding its eyes is a white supercilium, black lores and black eye line. What makes this bird so unique is its bright yellow crown bordered by a solid black line around the edge. The wings of this bird are greyish in color on both sides, with a lighter grey on the underside of the wing. When relaxed, a dark grey to black line is clearly visible at the base of the primaries and secondaries, with a contrasting white wing bar on the secondaries. Just like the Ruby-crowned Kinglet, this bird has pencil thin legs (tarsus), and if you look closely you’ll notice that the feet are yellowish in color. (Audubon, n.d.).

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The plumage color of both the male and female Golden-crowned Kinglet are very similar with subtle differences that help sex the bird. The male has an orange tinge in the center of its crown that is typically only visible when the bird puts it on display for a mate or when it’s agitated. The female lacks that orange tinge on its crown, and it also has pointier juvenile tail feathers than the male (All About Birds, n.d.).

Juvenile Plumage

The Juvenile plumage of this bird is grayer looking than when it’s grown in its adult feathers, and the yellow crown on top of its head doesn’t fully come in until after its hatch year. This drab olive colored crown looks an awful lot like the adult Ruby-crowned Kinglet, so try not to get them mixed up! (Hint: The Ruby-crowned Kinglet has a much plainer looking face apart from its white eye ring) (All About Birds, n.d.) (Vancouver Avian Research Center, n.d.).

What it sounds like:

The song of the Golden-crowned Kinglet is a series of very high pitch “Tsee” sounds followed by a lower pitched tumble that resembles a chickadee (All About Birds, n.d.).

Nesting & Geographical map

Habitat

These birds prefer to live in mature coniferous forests during the mating season, especially spruce, fir, and hemlock, but any other time of the year any decently thick woodland will do (The Gall Lab, 2017). Looking at the geographical range map, populations of the Golden-crowned Kinglet near the eastern and western coasts of North America choose to nest in the same region year-round, while populations that nest more Central in America migrate south during the winter. The Golden-crowned Kinglet is well known for surviving cold northern winters, even with its particularly small body size. To survive these cold climates, they nest high up in very dense branches of mature coniferous trees. This branchy habitat choice also makes it difficult to spot these bite-sized birds (All About Birds, n.d.).

Behavior

The Golden-crowned Kinglet is a monogamous bird, splitting the daily duties between the opposite-sex mate. The male is the aggressive territorial one, repeatedly making its call and perking up its crown to deter enemies away from the nest, such as predators and other competing males during the nesting season. The male is also in charge of retrieving food for the mother and their young. The female’s role is to incubate the eggs and to look after the young, so it doesn’t spend too much of its energy away from the nest during the mating/hatching season (All About Birds, n.d.) (Audubon, n.d.).

Conservation

The conservation status of the Golden-crowned Kinglet is considered to be “least concern” as their population size is still strong with a global population of approximately 100 million (All About Birds, n.d.). Although the global population is stable, the population in North America is shifting towards the east coast with the populations decreasing in the west. Because of the kinglets varied winter habitat, they have been able expand southward into spruce plantings in Pennsylvania, Illinois, Indiana, and Ohio. On a local scale, the most prominent disturbances to the Golden-crowned Kinglets are logging and forest fires (All About Birds, n.d.).

Papers and Articles

“Window collisions by migratory bird species: urban geographical patterns and habitat associations”

• Published in 2015 by Marine Cusa et al., in the Journal “Urban Ecosystems”

Building collisions are known to be one of the leading causes of bird mortalities around the world, and with urban areas only becoming taller and denser with the rapidly increasing human population, bird mortalities are only going to become more frequent.

In a study by Marine Cusa et al. in 2015, species-specific strike patterns are monitored to try to find the cause of all the collision deaths so that the effects can be minimized. The Fatal Light Awareness Program Canada (FLAP) collected bird-window collision data in three distinct regions of Toronto, Canada during the migratory season of the years 2009 and 2010. The FLAP volunteers collected and recorded a total of 3034 bird collisions in 2009 and 4934 bird collisions in 2010, and they found that the species with the greatest number of collisions was unanimously the Golden-crowned Kinglet (n = 808).

Cusa et al. found that increasing glass surface area percentage is correlated to higher bird mortality due to collision. They also found that the Golden-crowned Kinglet tended to collide more regularly in less urbanized sites suggesting that those species are simply more sensitive to urban development than other bird species.

“Carotenoid‐based plumage coloration in golden‐crowned kinglets Regulus satrapa: pigment characterization and relationships with migratory timing and condition”

• Published in 2011 by C. K. S. Chui et al, in the Journal of Avian Biology

Because migrating and developing colorful plumage are both energy costly events during a bird’s annual cycle, it wouldn’t be surprising to see less devotion to fully produce the most vibrantly colourful contour feathers on the market, in order to focus more of that energy on storing fat before migrating.

In this study, 186 Golden‐crowned Kinglets were banded at a common stopover site during their fall migrational period to measure the colouration of their plumage and several other measurable factors that would indicate their physical condition, which were then compared with respect to their individual arrival dates past the banding site. To measure the colouration of the feathers, they used reflectance spectrometry to quantify crown colouration, and they analysed feather carotenoids using high-performance liquid chromatography.

C. K. S. Chui et al. proposed that the Central American Golden-crowned Kinglets that migrated south earlier in the fall are more fit for several reasons; one reason that more fit individuals leave their northern mating grounds sooner is because they are more efficient in storing energy, so that they don’t have to stay in the mating grounds for as long. Another reason was that the earlier fall-migrating Golden-crowned Kinglets are more likely to avoid migratory predatory birds, such as Northern Shrikes (Lanius excubitor) and northern saw‐whet owls (Aegolius acadicus).

Looking at their collection of data, they found that earlier male migrants grew their tail feathers faster, and that the earlier male and female migrating birds also had higher carotenoid-based pigmentation in their crown feathers, and therefor must be in better nutritional condition. They theorised that if crown coloration plays a role in competition and mate choice, then more colourful males may be able to secure better breeding territories or attract high‐quality females earlier in the season, which could advance their breeding and thus enable earlier fall migration, ultimately leading to their increased fitness among the population.

Thanks for reading!

References

All About Birds. https://www.allaboutbirds.org/guide/Golden-crowned_Kinglet/overview

Audubon. https://www.audubon.org/field-guide/bird/golden-crowned-kinglet

Celia K. S. Chui, McGraw, K. J., & Doucet, S. M. (2011). Carotenoid-based plumage coloration in Golden-crowned Kinglets “regulus satrapa”: Pigment characterization and relationships with migratory timing and condition. Journal of Avian Biology, 42(4), 309-322.

Cornell Lab of Ornithology. https://birdsna.org/Species-Account/bna/species/gockin/introduction

Cusa, M., Jackson, D. A., & Mesure, M. (2015). Window collisions by migratory bird species: Urban geographical patterns and habitat associations. Urban Ecosystems, 18(4), 1427-1446. doi:10.1007/s11252-015-0459-3

The Gall Lab. (2017). https://pages.vassar.edu/sensoryecology/birds-with-friends-the-golden-crowned-kinglet/

Vancouver Avian Research Center. http://www.birdvancouver.com/b_golden-crowned_kinglet.html

Wikipedia. https://en.wikipedia.org/wiki/Golden-crowned_kinglet

Photos (by order of appearance):

Jacob MckGinnis. https://www.allaboutbirds.org/guide/Golden-crowned_Kinglet/media-browser/67476631

Ian Davies. https://birdsna.org/Species-Account/bna/species/gockin/introduction

The Gall Lab. https://pages.vassar.edu/sensoryecology/birds-with-friends-the-golden-crowned-kinglet/

Gates Dupont. https://www.allaboutbirds.org/guide/Golden-crowned_Kinglet/id

Range Map. https://identify.whatbird.com/img/4/56224/image.aspx

Deadfall. Mark Thiessen. National Geographic. Retrieved from D2L slides

Weaver, R.J., Santos, E.S.A., Tucker, A.M. et al. Carotenoid metabolism strengthens the link between feather coloration and individual quality. Nat Commun 9, 73 (2018) doi:10.1038/s41467-017-02649-z

The Gall Lab. https://oyiabrown.files.wordpress.com/2015/01/golden_crowned-kinglet-2.jpg