Icterus spurius

Orchard Oriole is a small, short-tailed oriole, weighing only 16-25 gm (0.6-0.9 oz). Instead of the usual orange or yellow and black plumage of other North American orioles, Orchard Oriole is a combination of black and chestnut.

All of the population in the United States and Canada is part of the nominate subspecies. Studies of genetic material indicate Orchard and Hooded (I. cucullatus) orioles are closely related (Freeman and Ink 1995).

During the breeding season, Orchard Orioles eat and feed their young almost exclusively insects, but on their wintering grounds in south Mexico, Central America and northern South America they consume fruit and drink nectar (Scharf and Kren. 1996).

DISTRIBUTION.During the 1987-1992 field work for the TBBA project, researchers found Orchard Orioles breeding widely across Texas, although abundance varies greatly. Breeding Bird Survey (BBS) data indicate Orchard Oriole is most abundant along the Louisiana border and in the Edwards Plateau region of the state, where breeding records on the TBBA map are thickest. Breeding densities are lowest in the Panhandle and west of the 103rd meridian (Sauer et al. 2004).

Elsewhere in North America Orchard Oriole is a widespread, common breeder in the eastern United States. Highest relative abundances are found in the southeastern states and the northern Great Plain. (Sauer et al. 2004),.

In Mexico, breeding occurs on the central plateau and in a narrow strip along the Gulf Coast in Veracruz. Orchard Orioles winter from west and south Mexico through Central America to Colombia and Venezuela (Scharf and Kren. 1996).

SEASONAL OCCURRENCE. Spring migrants appear in Texas from early April (extreme March 5) to late May and Orchard Orioles move south from early July to mid-September (extreme November 6). There are occasional winter records within the state (Oberholser 1974). The earliest egg date for Texas is May 19, and eggs are normally found until late July. Only one brood is raised per year, but another clutch may be laid if a clutch is lost due to late cold weather (Scharf and Kren. 1996). TBBA field observers found confirmed breeding evidence on dates ranging from April 1 to July 26.

BREEDING HABITAT. In Texas Orchard Orioles are found in rural and suburban areas and most frequently nest in mesquite trees, although they also use a variety of other small, scattered trees. The species often nests near the nest of an Eastern (Tyrannus tyrannus) or Western (T. verticalis) kingbird, perhaps benefiting from these species vigorous defense of their nests against potential predators or brood parasites. In preferred habitat Orchard Oriole nests may be close together and the species has been described as “semi-colonial” or “non-territorial” (Scharf and Kren. 1996).

The nest is a small, partially pensile basket, often in an upright fork and attached at the rim and sometimes sides. The nest is usually 3-6 m (10-20 ft.) above ground and is made of fresh or dried grasses or Spanish moss, sometimes only grass, and is lined with fine vegetable fiber or animal hair. The female oriole builds the nest, concealed among leaves, in 3-6 days. The usual clutch size is 5 with a range of 3-7 eggs (Oberholser 1974, Harrison 1979). The female incubates the eggs for 12-14 days; the young birds spend 2 weeks in the nest before fledging. They spend another week in dense cover near the nest before moving away in a family group (Scharf and Kren. 1996).

STATUS. Lockwood and Freeman (2004) describe this species as uncommon to locally common in the eastern two-thirds of Texas and locally uncommon to rare in the rest of the state. The highest density of Orchard Oriole in the state is apparently in extreme east Texas (Jasper County). It is among the highest abundances in the United States. On a BBS route there, the average number of Orchard Orioles reported over 6 years was 33 per 40 km (25 mi) route. From the Louisiana border, breeding densities decrease to 2-3 birds per route at the 95th meridian. In the Edwards Plateau region, north of Del Rio and the Amistad Reservoir, densities are as high as 4-10 orioles per route. Densities across the rest of the state are lower (Price et al. 1995 , Sauer et al 2004)

Orchard Oriole in Texas has declined greatly in recent decades (Lockwood and Freeman 2004), BBS data quantify this, indicating a statistically significant 5.4% average annual decline for the period 1966-2003 (Sauer et al. 2004). Oberholser (1974) reported nesting has been infrequent in the lower Rio Grande valley since the 1960’s and TBBA data (see map) concur with this conclusion as well as with Oberholser’s (1974) map. Orchard Orioles are heavily parasitized by cowbirds in many areas (Scharf and Kren. 1996). The Hooded Oriole account contains further discussion of species declines in the lower Rio Grande valley.

As Lockwood and Freeman (2004) and BBS data indicate, the status of Orchard Oriole as a breeding bird in Texas is close to precarious, except along the Louisiana border. The BBS trend for this species in Texas suggests the present summer population in this state is only about 10% of the 1966 population.

While Orchard Oriole may almost disappear from the breeding avifauna of Texas in the near future, it will probably remain as a migrant . Lockwood and Freeman (2004) list it as an uncommon to common migrant in much of the state and the BBS trend for the United States and Canada is a relatively small -0.8% change per year for the 1966-2003 period.  Text by Robert C. Tweit (2005)

Literature cited: 
Freeman, S. and R. M. Ink. 1995. A phylogenetic study of the blackbirds based on mitochondrial DNA restriction sites. Sys. Biol. 44: 409-420.

Harrison, H. H. 1979. A field guide to western birds’ nests. Houghton Mifflin, Boston, MA

Lockwood, M. W. and B. Freeman. 2004. The TOS handbook of Texas birds. Texas A&M University Press, College Station.

Oberholser, H. C. 1974. The bird life of Texas, Vol. 2. Univ. of Texas Press, Austin.

Price, J., S. Droege, and A. Price. 1995. The summer atlas of North American birds. Academic Press, New York.

Sauer, J. R., J. E. Hines, and J. Fallon. 2004. The North American Breeding Bird Survey, results and analysis 1966-2003. USGS Patuxent Wildlife Research Center, laurel MD (Web site, http://www.mbr-pwrc.usgs.gov/bbs).

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 Birds of North America, Inc., Philadelphia, PA