Crescent-chested warbler

Crescent-chested warbler
Singing male crescent-chested warbler on a tree branch.
Conservation status
Least Concern  (IUCN 3.1) [1]
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Passeriformes
Family:	Parulidae
Genus:	Oreothlypis
Species:	O. superciliosa
Binomial name
Oreothlypis superciliosa (Hartlaub, 1844)
Range of the crescent-chested warbler
Synonyms
Parula superciliosa

The crescent-chested warbler (Oreothlypis superciliosa) is a small, New World warbler that is found throughout North and Central America from Texas to Nicaragua. ^[2] This bird is similar to other warblers, however, certain features set them apart. This warbler is noticeable different than most warblers due to its brightly colored plumage and distinct features such as a white supercilium and orange crescent on its breast. ^[3] Crescent-chested warblers create their nests near the ground and eggs are incubated by the female. ^[2] Furthermore, there are differences in the plumage of these warblers depending on their age and sex such as down in young birds and more present crescents on male birds. ^[3] These birds are foragers and eat insects. ^[4] They are also migratory birds and normally survive in flocks. ^[3] Lastly, the crescent-chested warbler has a number of predators including rodents and other avian predators. ^[4]

Description

Plumage and color

The crescent-chested warbler is noticeably different than most North American warblers. It is superficially similar to both the northern parula (Parula americana) and the tropical parula (P. pitiayumi) with yellow underparts, a gray head, and a greenish back. ^[3] The bird's feathers do not have many patterns but are brightly colored. The head of the warbler as well as the ear coverts and the crown are a gray color that contains a blueish hint to it. The loral area, located between the bottom of the beak and the eyes, is a darker gray than the head and ear coverts of the bird. This bird also presents a distinct white supercilium above its eyes that connects with the loral area. There is variety on the shape of the supercilium depending on the individual, but only at its ending point. The gray of the ear coverts becomes more of a muted gray as it travels down the side of the neck. This gray travels towards the front of the bird's body and connects with a bright yellow throat, breast, and underside. Sometimes, these warblers will display a reddish smudge on their breast, commonly found on those inhabiting lowland Sonora. The underside of the bird can span from a pale to a bright white with some patches of light gray. The upper back towards the rump of the bird is a strong olive green while the tail of the bird is a medium gray or white. Sometimes, the crescent-chested warblers exhibit pale markings near the bend of wings, a similar characteristic to the orange-crowned warbler. ^[3]

The crescent-chested warbler's beak has a lower bottom when compared to other species of warblers and it ends in a sharp, thin point. The upper mandible of the warbler is black and the bottom mandible has a dark tip but is mostly pale. It has muted orange feet and legs as well as dark eyes. Adult males have a discrete chestnut crescent on the breast, which is less prominent and sometimes lacking in females and young birds. ^[3]

Other characteristics

Similar to the orange-crowned warbler and Nashville warbler (Vermivora ruficapuilla) in shape and size, the crescent-chested warbler is a small to medium sized bird with a small head and short tail. The crescent-chested warbler tends to be smaller than the orange-crowned warbler and have a rounder breast and longer beak. ^[3] Similar to the orange-crowned warbler's quiet ship and the calls of the bridled titmouse, the crescent-chested warbler produces a softer sound but more profound and richer. ^[3]

Behaviors

Breeding

Crescent-chested warblers make their nests atop grassy tussocks or sheltered by a hill or bank near the ground. Usually they will have one or two broods a year. The female is believed to build the nest without help from the male, gathering moss, grass, conifer needles, and fine materials to line the nest. She will then lay approximately three plain white eggs. Incubation is estimated to last 12 – 14 days by the female. The chicks are altricial and are also brooded by the female, and fed by both sexes. The young stay in the nest for an estimated 8–10 days. ^[2] During this time, the female will exhibitions of distraction displays, acting as if she is injured, in order to lure off predators. ^[5]

Age and sex differences

There are a few differences between male and female crescent-chested warblers that signify its age and sex. For example, males tend to have more developed "crescents" on their chests when compared to females. Plumage on these birds can also signify their age. Juvenal plumage on the crescent-chested warblers consist of brown upper wings, and pale wing markings. ^[3] Newly hatched chicks have dark brownish-gray down. ^[5]

Diet

The crescent-chested warbler often forages through trees including oak (Quercus), Arizona Sycamore (Platanus wrightii), juniper (juniperus),, and Arizona Walnut (Juglans major), They forage in trees near rivers as well as hillsides for insects. ^[2]

Location

The crescent-chested warbler is common throughout montane ranges, from northern Mexico to northern Nicaragua, and is occasionally vagrant to Texas and Southeast Arizona. ^[2] The crescent-chested warblers that inhabit Northeastern Mexico are located near the border of Texas and found in Nuevo León in a mountain range called the Sierra Picachos. They have also been found very far north in Sonora east of the region of Tezopaco. These birds normally inhabit areas at high elevations from about 4,000 to 11,000 feet. ^[3] However, they are sometimes also found at lower elevations. ^[2]

Migratory patterns

Depending on where the crescent-chested warbler is located, it can be a migratory bird. During the winter, warblers located in North America migrate in flocks to Mexico. Large numbers of these birds have been found within single flocks throughout the non-breeding season in areas such as the broad leaf forest in Rancho Liebre Barranca, Sinaloa which could be evidence for migration in these flocks. ^[3]

Survival

Predators

Warblers have a number of predators, normally consisting of smaller mammals and other avian predators like rodents. Mice, weasels, martens, buzzards, and owls have all been known to eat young warblers as well as their eggs. ^[6] Habitat destruction due to human activity is a threat to these bird species. ^[2]

References

1. BirdLife International (2020). "Oreothlypis superciliosa". IUCN Red List of Threatened Species . 2020 e.T22721645A137343705. doi: 10.2305/IUCN.UK.2020-3.RLTS.T22721645A137343705.en . Retrieved 20 September 2024.
2. Soberanes-González, Carlos A.; Rodríguez-Flores, Claudia I.; Arizmendi, Marîa del Coro; Schulenberg, Thomas S. (2020). "Crescent-chested Warbler (Oreothlypis superciliosa), version 1.0". Birds of the World. doi:10.2173/bow.crcwar.01. ISSN   2771-3105.
3. Heathcote, Daniel (March 1, 1985). "Crescent-chested Warbler in Arizona". Digital Commons. Retrieved September 21, 2025.
4. Szymkowiak, Jakub (29 January 2015). "Avoiding predators in a fluctuating environment: responses of the wood warbler to pulsed resources" (PDF). International Society for Behavioral Ecology. Retrieved 7 October 2025.
5. Mayfield, Harold F. (July 1, 1968). "Nests of the Red Warbler and Crescent-chested Warbler in Oaxaca, Mexico". Digital Commons at the University of South Florida. Retrieved October 4, 2025.
6. Szymkowiak, Jakub (29 January 2015). "Avoiding predators in a fluctuating environment: responses of the wood warbler to pulsed resources" (PDF). International Society for Behavioral Ecology. Retrieved 7 October 2025.

Further reading

• Skutch, Alexander F. (1954). "Hartlaub warbler" (PDF). Life Histories of Central American Birds. Pacific Coast Avifauna, Number 31. Berkeley, California: Cooper Ornithological Society. pp. 377–382.