Hooded Orioles are spring and summer residents of south Texas and the Rio Grande River valley upstream to Big Bend National Park. The male with his orange head is perhaps the most spectacular of the 8 oriole species in Texas. This race, cucullatus, slightly smaller, with an orange to orange-yellow head in males, breeds from Texas south along the east Mexican coastal plain to Belize. Another race, nelsoni, larger, with a paler, yellow to orange-yellow head in males, breeds from California and northwest Mexico, including the Baja Peninsula, east to southern New Mexico and perhaps extreme west Texas (Pyle 1997, Pleasants and Albano. 2001). The boundary between these two groups needs further clarification; Oberholser (1974) placed birds from Big Bend National Park in the nelsoni group. The TBBA map shows observations from the Rio Grande delta up river through Big Bend suggesting that the dividing line is further west. Since the El Paso observation was not a confirmed one, the nelsoni group may no longer breed regularly in Texas.
Male Hooded Orioles do not acquire full adult plumage until their second fall. No data are available on whether any second-year males attract mates and breed (Pyle 1997, Pleasants and Albano. 2001).
Recent molecular genetic studies indicate Hooded and Orchard (I. spurius) orioles are closely related even though their plumages contrast sharply (Omland et al. 1999).
DISTRIBUTION. In Texas during the 1987-1992 TBBA field work volunteers found Hooded Orioles breeding most densely in the lower Rio Grande valley as far up stream as Laredo, and along the Gulf Coast as far north as Corpus Christi. Breeding was also found in the South Texas Brush Country, Edwards Plateau and Big Bend National Park areas.
SEASONAL OCCURRENCE. Most Hooded Orioles arrive in mid-March and probably leave by mid- or late September. Eggs have been collected between April 3 and August 9 (Oberholser 1974, Pleasants and Albano. 2001). May and June probably represent the peak of the breeding season as TBBA atlasers found confirmed breeding evidence May 27 and June 2.
BREEDING HABITAT. In Texas the elevational breeding range of Hooded Oriole extends from sea level to 900 m (3000 ft;; Oberholser 1974). While this species in Texas was originally most common in the thick riparian vegetation of the Rio Grande valley, the species have adapted to planted vegetation, especially palms. Outside towns these orioles often place nests in Texas ebony, mesquite, cottonwood, willow, ash, elm, and pecan trees or yuccas. Nests of Hooded Orioles are often suspended from the underside of palm fronds or attached to pecan leaves. The nests are woven of fresh or dry grasses and palm or yucca fibers. The eggcup is lined with finer grasses and other soft vegetable material. Clutch size is usually 4-5 eggs, range 3-5. Only the female incubates the eggs. Because nests are difficult to inspect, the incubation period is unknown and the young birds apparently leave the nest about two weeks after hatching (Oberholser 1974, Pleasants and Albano. 2001).
STATUS. The species suffered a drastic decline in the lower Rio Grande valley in the last half of the twentieth century. Early ornithologists found Hooded Oriole abundant in the valley in the late nineteenth century and its population apparently remained high through the first half of the twentieth century (e. g. 400 breeding pairs in Santa Ana National Wildlife Refuge). Then a rapid population decline began in the refuge, and by 1971 no breeding pairs were present (Pleasants and Albano 2001), although at least one male frequented a refuge feeder in April 1971 (RCT pers. obs.). Recently a few pairs have returned to the refuge. In 1996-1997 surveys of riparian areas in Hidalgo County did not find Hooded Orioles (Rupert and Brush 2006).
Oberholser (1974) suggests a hard freeze in the Rio Grande delta in January-February 1951 may have initiated the decline by killing citrus groves. Many farmers switched to raising cotton, vastly increasing the use of pesticides and herbicides, including DDT. Cattle feedlots were established to utilize cotton byproducts and the feedlots provided ideal winter habitat for cowbirds.
Further west along the Rio Grande River, Oberholser’s (1974) map shows spring and summer observations along the river between Big Bend National Park and El Paso. TBBA atlasers did not find breeding evidence between these two points or at an area on the west edge of the Panhandle, suggesting breeding in Texas west of Big Bend is rare at best.
Lockwood and Freeman (2004) classify Hooded Oriole as an uncommon and local summer resident in areas of Texas near the Rio Grande.
Breeding Bird Survey (BBS) observers found an average of one or less Hooded Orioles per 40 km (25 mi) route in all areas where TBBA volunteers found breeding evidence except Laguna Atascosa where the BBS workers reported 2-3 orioles per route. In comparison in an area of southeast Arizona with much less habitat alteration than the lower Rio Grande River valley has undergone, BBS workers found 4-10 Hooded Orioles per route (Sauer et al. 2004).
The BBS method does not include a large enough sample of Hooded Orioles to allow calculation of a statistically significant trend, either nationally or for Texas (Sauer et al. 2004).
While the decline of this beautiful bird in Texas can not be quantified, its continued presence as a part of the Texas avifauna seems precarious. Text by Robert C. Tweit (2007)
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. University of Texas Press, Austin.
Omland, K. E., S. M. Lanyon, and S. J. Fritz. 1999. A. molecular phylogeny of the New World orioles (Icterus): the importance of dense taxon sampling. Mol. Phylogenetics Evol. 12: 224-239.
Pleasants, B. Y., and D. J. Albano. 2001. Hooded Oriole (Icterus cucullatus). In The birds of North America, No. 568 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.
Pyle, P. 1997. Identification guide to North American Birds, Part I, slate Creek Press, Bolinas, CA.
Rupert, C. and T. Brush. 2006. Habitat use of breeding birds in riparian forest of the lower Rio Grande valley of Texas. Bull. Texas Ornith. Soc. 39: 48-58.
Sauer, J. R., J. E. Hines, and J. Fallon. 2004. The North American Breeding Bird Survey, results and analysis 1966-2003. Version 2004.1. USGS Patuxent Wildlife Research Center, Laurel MD (Web site, http://www.mbr-pwrc.usgs.gov/bbs).