Orchard oriole

The orchard oriole (Icterus spurius) is the smallest species of icterid. The subspecies of the Caribbean coast of Mexico, I. s. fuertesi, is sometimes considered a separate species, the ochre oriole or Fuertes's oriole.

The orchard oriole is a small bird with a length of 5.9-7.1 inches, a weight of 0.6-1.0 ounces, and a wingspan of 9.8 inches. Adult males have chestnut or ochre underparts, while adult females and juveniles have olive-green upper parts and yellowish breasts and bellies. They inhabit semi-open areas with deciduous trees in eastern North America, southern Tamaulipas, and Veracruz. Their winter range extends from central Sinaloa and southern Veracruz to northern Colombia and northwestern Venezuela.

Orchard orioles prefer living near lakes and streams, nesting in tightly woven pouches attached to horizontal tree branches. They are nocturnal migrants and feed on insects, spiders, fruit, nectar, and seeds depending on the season. During flight, they usually swoop close to the ground and fly at or below treetop level. Courtship displays include bowing, seesawing, and begging. The species name "spurius" refers to their original misidentification as female Baltimore orioles, and they are sometimes mistaken for New World warblers.

Description
Measurements:


 * Length: 5.9-7.1 in (15-18 cm)
 * Weight: 0.6-1.0 oz (16-28 g)
 * Wingspan: 9.8 in (25 cm)

The bill is pointed and black with some blue-gray at the base of the lower mandible. The adult male of the nominate subspecies has chestnut on the underparts, shoulder, and rump, with the rest of the plumage black. In the subspecies I. s. fuertesi, the chestnut is replaced with ochre. The adult female and the juvenile of both subspecies have olive-green on the upper parts and yellowish on the breast and belly. All adults have pointed bills and white wing bars. (Orchard orioles are considered to be adults after their second year.) One-year-old males are yellow-greenish with black lores and bib.

Habitat and range
The breeding habitat is semi-open areas with deciduous trees. I. s. spurius breeds in spring across eastern North America from near the Canada–United States border south to central Mexico. A 2009 study also found breeding in the thorn forest of Baja California Sur and the coast of Sinaloa during the summer "monsoon"; this region had previously been thought to be only a migratory stopover. I. s. fuertesi breeds from southern Tamaulipas to Veracruz. There is a record of a specimen of fuertesi from Cameron County, Texas. These birds prefer living in shaded trees within parks along lakes and streams. The nest is a tightly woven pouch attached to a fork on a horizontal branch. Their nests tend to sit close together.

The nominate subspecies' winter range extends from the coastal lowlands of central Sinaloa and southern Veracruz south to northern Colombia and northwestern Venezuela (Scharf and Kren 1996). The ochre subspecies has been observed in winter on the Pacific slope of Mexico.

Nominate orchard orioles depart from their winter habitats in March and April and arrive in their breeding habitats from late April to late May. Usually, they leave their breeding territories in late July and early August and arrive on their winter territories in mid August. These birds are nocturnal migrants.

Diet
While in breeding season, they eat insects and spiders. When the season changes, their diet also includes ripe fruit, which quickly passes through their digestive tract. During the winter, their diet consists of fruit, nectar, insects and seeds.

Behavior
When in flight, orchard orioles generally swoop close to the ground and fly at or below treetop level.

During courtship, females display themselves in three ways. The first is by bowing their head and torso toward the male. Seesawing, the second courtship display, involves repetitively alternating lowering and raising the head and tail. The third display is begging, which is fast-paced fluttering of wings halfway extended, followed by a high whistle.

Etymology
The specific name spurius refers to the original misidentification of the male as a female Baltimore oriole. These birds are sometimes mistakenly identified as New World warblers.

Book

 * Scharf, W. C., and J. Kren. 1996. Orchard Oriole (Icterus spurius). In The Birds of North America, No. 255 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists’ Union, Washington, D.C.

Thesis

 * Enstrom DA. Ph.D. (1990). Investigations of delayed plumage maturation in the orchard oriole. University of Illinois at Urbana-Champaign, United States, Illinois.
 * Witt JW. Ph.D. (2005). Shrub and grassland birds at Occoquan Bay National Wildlife Refuge in northern Virginia and the influence burning and mowing has had upon their distribution and abundance. George Mason University, United States, Virginia.

Articles

 * Baker JM, Lopez-Medrano E, Navarro-Siguenza AG, Rojas-Soto OR & Omland KE. (2003). Recent speciation in the Orchard Oriole group: Divergence of Icterus spurius spurius and Icterus spurius fuertesi. Auk. vol 120, no 3. p. 848-859.
 * Beaton G. (1994). Late Orchard Oriole found in Clayton County. Oriole. vol 59, no 1. p. 25-26.
 * Binford LC. (1971). Roadrunner Captures Orchard Oriole in California. California Birds. vol 2, no 4.
 * Bjorklund CF. (1990). Bromhead Saskatchewan Canada Rare Bird Records. Blue Jay. vol 48, no 4. p. 212-217.
 * DePaul L & Kopitzke D. (1998). Incentives for savanna protection on private lands: Past, present, and future. Transactions of the Wisconsin Academy of Sciences Arts & Letters. vol 86, no 0. p. 47-56.
 * Elliott PF. (1978). Cowbird Parasitism in the Kansas USA Tall Grass Prairie. Auk. vol 95, no 1. p. 161-167.
 * Enstrom DA. (1992). Breeding Season Communication Hypotheses for Delayed Plumage Maturation in Passerines Tests in the Orchard Oriole Icterus-Spurius. Animal Behaviour. vol 43, no 3. p. 463-472.
 * Enstrom DA. (1992). Delayed Plumage Maturation in the Orchard Oriole Icterus-Spurius Tests of Winter Adaptation Hypotheses. Behavioral Ecology & Sociobiology. vol 30, no 1. p. 35-42.
 * Enstrom DA. (1993). Female choice for age-specific plumage in the orchard oriole: Implications for delayed plumage maturation. Animal Behaviour. vol 45, no 3. p. 435-442.
 * Garvin MC, Szell CC & Moore FR. (2006). Blood parasites of Nearctic-Neotropical migrant passerine birds during spring trans-gulf migration: Impact on host body condition. Journal of Parasitology. vol 92, no 5. p. 990-996.
 * Goertz JW. (1977). Additional Records of Brown-Headed Cowbird Nest Parasitism in Louisiana. Auk. vol 94, no 2. p. 386-389.
 * Hill RA. (1976). Host Parasite Relationships of the Brown-Headed Cowbird in a Prairie Habitat of West Central Kansas USA. Wilson Bulletin. vol 88, no 4. p. 555-565.
 * Hilton GM, Atkinson PW, Gray GAL, Arendt WJ & Gibbons DW. (2003). Rapid decline of the volcanically threatened Montserrat oriole. Biol Conserv. vol 111, no 1. p. 79-89.
 * Hofmann CM, Cronin TW & Omland KE. (2006). Using spectral data to reconstruct evolutionary changes in coloration: Carotenoid color evolution in new world orioles. Evolution. vol 60, no 8. p. 1680-1691.
 * Hopkins MJ. (1968). A Disputed Nest Site Tyrannus-Tyrannus Icterus-Spurius Behavior. Oriole. vol 33, no 3. p. 37-38.
 * Leck C. (1974). Further Observations of Nectar Feeding by Orioles. Auk. vol 91, no 1. p. 162-163.
 * Lee JH, Hassan H, Hill G, Cupp EW, Higazi TB, Mitchell CJ, Godsey MS, Jr. & Unnasch TR. (2002). Identification of mosquito avian-derived blood meals by polymerase chain reaction-heteroduplex analysis. American Journal of Tropical Medicine & Hygiene. vol 66, no 5. p. 599-604.
 * Lloyd-Evans TL & Atwood JL. (2004). 32 years of changes in passerine numbers during spring and fall migrations in coastal Massachusetts. Wilson Bulletin. vol 116, no 1. p. 1-16.
 * Lohrer FE. (1977). Orchard Oriole Holding Food with the Feet. Florida Field Naturalist. vol 5, no 2.
 * Luterbach B. (1999). Orchard Orioles increase within Tyvan area, Saskatchewan. Blue Jay. vol 57, no 3. p. 150-151.
 * Mills ED & Rogers DTJ. (1990). Nearctic Passerine Fall Migration in Central Belize. Wilson Bulletin. vol 102, no 1. p. 146-150.
 * Morton ES. (1979). EFFECTIVE POLLINATION OF ERYTHRINA-FUSCA BY THE ORCHARD ORIOLE (ICTERUS-SPURIUS) - CO-EVOLVED BEHAVIORAL MANIPULATION. Ann Mo Bot Gard. vol 66, no 3. p. 482-489.
 * Parkes KC. (1990). Additional Record of Birds from the Distrito Federal Mexico Including a Possible Hybrid Spizella. Condor. vol 92, no 4. p. 1080-1081.
 * Quintana-Barrios L, Ruiz-Campos G, Unitt P & Erickson RA. (2006). Update on the birds of Isla Guadalupe, Baja California. Western Birds. vol 37, no 1. p. 23-36.
 * Schaefer VH. (1976). Geographic Variation in the Placement and Structure of Oriole Nests. Condor. vol 78, no 4. p. 443-448.
 * Scharf WC & Kren J. (1997). Summer diet of orchard orioles in southwestern Nebraska. Southwestern Naturalist. vol 42, no 2. p. 127-131.
 * Sealy SG. (1980). Breeding Biology of Orchard Orioles Icterus-Spurius in a New Population in Manitoba Canada. Canadian Field Naturalist. vol 94, no 2. p. 154-158.
 * Sealy SG & Underwood TJ. (2004). Accepters and rejecters of cowbird parasitism in the New World orioles (Icterus spp.). Ornitologia Neotropical. vol 15, no 3. p. 331-347.
 * Short LL. (1974). Nesting of Southern Sonoran Birds During the Summer Rainy Season. Condor. vol 76, no 1. p. 21-32.
 * Stevenson HM. (1979). Southward Extension of Orchard Oriole Icterus-Spurius Breeding Range in Florida USA. Florida Field Naturalist. vol 7, no 1. p. 10-11.
 * Twedt DJ & Somershoe SG. (2003). Breeding birds on reforested bottomlands in forested and agricultural landscapes. Ecological Society of America Annual Meeting Abstracts. vol 88, no 339.
 * Van Dyke F, Van Kley SE, Page CE & Van Beek JG. (2004). Restoration efforts for plant and bird communities in tallgrass prairies using prescribed burning and mowing. Restoration Ecology. vol 12, no 4. p. 575-585.
 * VanderWerf EA & Freed LA. (2003). Elepaio subadult plumages reduce aggression through graded status-signaling, not mimicry. Journal of Field Ornithology. vol 74, no 4. p. 406-415.
 * Whitehead MA, Schweitzer SH & Post W. (2002). Cowbird/host interactions in a southeastern old-field: A recent contact area?. Journal of Field Ornithology. vol 73, no 4. p. 379-386.
 * Wormington A & Lamond W. (1987). Orchard Oriole New to Northern Ontario Canada. Ontario Birds. vol 5, no 1. p. 32-34. -->