Grace´s warbler (
Setophaga graciae) is a small New World warbler that specializes in pine woods.
Taxonomy: Grace´s warbler was discovered by Elliott Coues in the Rocky Mountains in 1864. He requested that the new species be named after his 18-year-old sister, Grace Darling Coues, and his request was honored when Spencer Fullerton Baird described the species scientifically in 1865.
Grace´s warbler is a small bird, 11–13 cm long. It is mostly gray on top, with broken black streaks across the back and flanks and two white bars on the wings. The throat and breast are a vibrant yellow, and the rest of the underparts are white. It has a yellow half-eye ring under the eye and a long yellow "eyebrow" stripe that starts at the base of the beak and runs above the eye, fading to white after it passes the eye.
Distribution and habitat: Grace´s warblers breed from the south-western United States to Nicaragua and winter in their breeding range from north-eastern Sinaloa and north-western Durango south. They are almost always found in pine forests, even in migration, though at the northern end of their range (in southern Nevada and Utah and southwestern Colorado) they occur in spruce-fir forest. They prefer open, "parklike" woods, and in some areas such as northern Arizona they prefer an understory of Gambel´s oak. In the United States and northern Mexico they typically occur at altitudes of 1800 to); farther south they may occur as low as 250 m. They are common in some localities, and in areas of the Mosquitia of Nicaragua where the only tree is the Caribbean pine, Grace´s warblers may be the only bird seen.
Grace´s Warbler is represented by four subspecies, including the nominate.
Setophaga graciae (S. F. Baird, 1865). Southern Nevada, southern Utah, southwestern Colorado, northern New Mexico, and western Texas south through eastern Sonora and western Chihuahua.
Setophaga graciae yaegeri (A. R. Phillips & Webster, 1961). West-central Mexico from southern Sinaloa, Durango, and Zacatecas south to Jalisco and Colima.
Setophaga graciae remota (Griscom, 1935). Pacific coast from Michoacan through Guerrero, Oaxaca, and Chiapas into Guatemala, El Salvador, Honduras, and northern Nicaragua.
Setophaga graciae decora (Ridgway, 1873). Belize.
Breeding: The nesting habits of Grace´s warblers are largely unknown, as nests are very rarely found. The nest is a compact cup of plant fibers, the inside lined with hair and feathers, placed high above ground on a tree branch, usually pine. The female lays 3 to 5 white or cream-colored eggs, speckled with brown, and ringed at the larger end.
Feeding: Like the vast majority of warblers, Grace´s warbler eats only insects and spiders, as far as is known from limited studies. It forages mostly high in pine trees (86% of its foraging time in a study in Arizona was in pines, but it foraged in oaks more in Mexico where olive warblers also occur). It catches its food from the bases of needle clusters and the upper bark of branches no thicker than its body. It will often hover to inspect pine cones for insect larvae. In Arizona it seldom flies to catch insects, but in Nicaragua it often does.
Books: - Stacier, C. A, and M. J. Guzy. 2002. Grace´s Warbler (Dendroica graciae). In The Birds of North America, No. 677 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.
Thesis: - Burgoyne PC. Ph.D. (1980). BIRD POPULATION CHANGES AND MANIPULATION OF A PONDEROSA PINE FOREST ON THE KAIBAB PLATEAU, ARIZONA. Brigham Young University, United States, Utah.
- Greene FP. Ph.D. (1989). Food resources, interspecific aggression, and community organization in a guild of insectivorous birds. Princeton University, United States, New Jersey.
Articles: - Chris K, Courtney JC & Patricia BJ. (2006). Distribution and Relative Abundance of Forest Birds in Relation to Burn Severity in Southeastern Arizona. Journal of Wildlife Management. vol 70, no 4. p. 1005.
- Craig AM. (1970). 2 California Records of Graces Warbler. California Birds. vol 1, no 2. pp. 77–78.
- Halbach U. (1976). Population Models and Syn Ecological Models in Ornithology. Journal fuer Ornithologie. vol 117, no 3. pp. 279–296.
- Johnson NK & Garrett KL. (1974). Interior Bird Species Expand Breeding Ranges into Southern California. Western Birds. vol 5, no 2. pp. 45–56.
- Maurer BA. (1983). Overlap and Competition in Avian Guilds. American Naturalist. vol 121, no 6. pp. 903–907.
- Rusterholz KA. (1981). Competition and the Structure of an Avian Foraging Guild. American Naturalist. vol 118, no 2. pp. 173–190.
- Staicer CA. (1989). Characteristics Use and Significance of Two Singing Behaviors in Grace´s Warbler Dendroica-Graciae. Auk. vol 106, no 1. pp. 49–63.
- Staicer CA & Guzy MJ. (2002). Grace´s Warbler: Dendroica graciae. Birds of North America. vol 677, pp. 1–19.
- Zinkl JG, Mack PD, Mount ME & Shea PJ. (1984). Brain Cholin Esterase Activity and Brain and Liver Residues in Wild Birds of a Forest Sprayed with Acephate. Environmental Toxicology & Chemistry. vol 3, no 1. pp. 79–88.
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