Orchard Oriole Icterus spurius Scientific name definitions

A widely distributed breeder east of the Rocky Mountains, the Orchard Oriole is associated with open woodlands, orchards, shrublands, shade trees in agricultural and suburban areas, wooded riparian areas, lakeshores, and marshes, and forest edges. It often nests in shade trees, seeming to thrive in habitats with low human density, including farms and parklands. It consumes mostly arthropods, gleaned from foliage, but also eats small ripe fruits and nectar when available. This species is only loosely territorial and is a solitary breeder in most habitats, though it is often described as “semi-colonial” in areas of prime habitat. Areas of dense nesting often have multiple nests per tree that can be seen when trees are leafless.

The Orchard Oriole overwinters in shrubby second-growth, open woodland, forest edge, clearings with scattered trees, and cultivated areas from central Mexico to Panama and, more rarely, northwestern South America. It leaves its overwintering grounds in March and April, sometimes returning south as early as mid-July. It nests relatively late in the northern part of its range where it raises only a single brood, presumably to accommodate the migratory schedule. The short time period spent on the breeding grounds has made it difficult to assign museum specimens to breeding localities and many presumed breeding specimens may actually be passage migrants. Double-brooding has been documented in Maryland and may occur more often than currently known in southern breeding areas.

This species exhibits delayed plumage maturation in males, with adults (Definitive Basic Plumage) having distinctive black and chestnut plumage, and first-year males (Formative Plumage) having yellow and greenish plumage and a black throat. Adult females (Definitive Basic) and juveniles of both sexes (Juvenile Plumage), are similar to first-year males but lack the black throat. Sexual dichromatism allows easy separation of two age-classes of males from females during all seasons, which makes this an excellent species for modeling demographic dynamics.

Breeding biology has been studied in Nebraska (1 Clawson, S. D. (1980). Comparative ecology of the Northern Oriole (Icterus galbula) and the Orchard Oriole (Icterus spurius) in Western Nebraska. M.S. thesis, University of Nebraska, Lincoln, NE, USA. Close , 2 Scharf, W. C., and G. W. Shugart (2021). Seasonal population structure of Orchard Orioles (Icterus spurius) captured in Nebraska (1992–2006). North American Bird Bander 46:13–18. Close ), Illinois (3 Enstrom, D. A. (1992). Breeding season communication hypotheses for delayed plumage maturation in passerines: tests in the orchard oriole, Icterus spurius. Animal Behaviour 43:463–472. Close , 4 Enstrom, D. A. (1993). Female choice for age-specific plumage in the Orchard Oriole: implications for delayed plumage maturation. Animal Behaviour 45:435–442. Close ), Manitoba (5 Sealy, S. G. (1980). Breeding biology of Orchard Orioles in a new population in Manitoba. Canadian Field-Naturalist 94:154–158. Close ), Arkansas (6 Thomas, R. H. (1946). An Orchard Oriole colony in Arkansas. Bird-Banding 17:161–167. Close ), the Mississippi Delta (7 Dennis, J. V. (1948). Observations on the Orchard Oriole in the lower Mississippi Delta. Bird-Banding 19:12–21. Close ), Maryland (8 Ligi, S., and K. Omland (2007). Contrasting breeding strategies of two sympatric orioles: first documentation of double brooding by Orchard Orioles. Journal of Field Ornithology 78(3):298–302. Close ), Florida (9 Stevenson, H. M. (1979). Southward extension of Orchard Oriole breeding range in Florida. Florida Field Naturalist 7:10–11. Close ), and Sinaloa, Mexico (10 Rohwer, S., and C. S. Wood (2013). Abundant early-summer breeding in Sinaloa does not suggest post-migration breeding in three potential double breeders. Wilson Journal of Ornithology 125:243–250. Close ). The adaptive significance of delayed plumage maturation in males has been the focus of several studies (3 Enstrom, D. A. (1992). Breeding season communication hypotheses for delayed plumage maturation in passerines: tests in the orchard oriole, Icterus spurius. Animal Behaviour 43:463–472. Close , 4 Enstrom, D. A. (1993). Female choice for age-specific plumage in the Orchard Oriole: implications for delayed plumage maturation. Animal Behaviour 45:435–442. Close , 11 Rohwer, S. (1978). Passerine subadult plumages and the deceptive acquisition of resources: a test of critical assumption. Condor 80:173–189. Close , 12 Rohwer, S., S. D. Fretwell, and D. M. Niles (1980). Delayed maturation in passerine plumages and the deceptive acquisition of resources. American Naturalist 115:404–437. Close ). Other research has examined spring and summer food habits and diet (13 Scharf, W. C., and J. Kren (1997). Summer diet of Orchard Orioles in southwestern Nebraska. Southwestern Naturalist 42(2):127–131. Close , 14 Wunderle, J. M. (1980). Nectar robbing by Orchard Orioles. Chat 44:107–108. Close ), and feeding and dominance hierarchies in Neotropical overwintering habitats (15 Enstrom, D. A. (1992). Delayed plumage maturation in the Orchard Oriole (Icterus spurius): tests of winter adaptation hypotheses. Behavioral Ecology and Sociobiology 30(1):35–42. Close , 16 Morton, E. S. (1979). Effective pollination of Erythrina fusca by the Orchard Oriole (Icterus spurius): coevolved behavioral manipulation. Annals of the Missouri Botanical Garden 66(3):482–489. Close ).