Nature Of Migration In The Species
A highly mobile species, especially in Northern Hemisphere. Northernmost populations undertake regular north-south migrations; Texas and Louisiana nesters are mainly resident. All populations show some postbreeding wandering. Well adapted to find new nesting areas when regular sites dry in droughts or are drained by humans. Most recoveries of birds banded as nestlings in Utah (205 of 222) have been in Mexico during nonbreeding season: 55 in Michoacan, 45 in Jalisco, 28 in Nayarit, 24 each in Guanajuato and Sinaloa, and 29 in 9 other states. Only 1 of 16 recoveries from Texas bandings has been in Mexico. Most recoveries from Oregon (5 of 7), Idaho (15 of 17), and Nevada (13 of 16) have been in winter in Mexico. Two of 4 recoveries of Colorado bandings have been from Mexico. Some east to west movement is suggested by 2 recoveries of Utah birds in California and 1 recovery of a Nevada bird in California.
Considered resident in south of range, though irregular local movements occur on a large scale throughout;birds ranged as chicks in Santa Fe north-central Argentina, were recovered in Rio Grande do Sul of southeast Brazil.Stragglers to Patagonia and Tierra del Fuego and at 4300m in the Andes of Bolivia.
Timing And Routes Of Migration
Most birds arrive at Utah and Idaho breeding areas in April and leave September-October; a few stragglers linger in Utah as late as Dececember. Begin migrating from Malheur National Wildlife Refuge [NWR], Oregon, in early August, and most have left by late September. Oregon birds return as early as 9 April, but average spring arrival date is 3 May. Colorado River Valley appears to be an important migration route between Great Basin nesting areas and Mexican wintering grounds.
Most South American populations do not migrate, although juvenile birds in South America do disperse after nesting. Stragglers reported as high as 4,300 m elevation in mountains of Bolivia and as far south as Straits of Magellan.
In North America adults and subadults wander far from breeding areas during late summer. Reports from Minnesota (formerly nested there), Arkansas, Tennessee (Waldron 1990), Illinois , Florida, Delaware, British Columbia, Baja California, and Hawaii. Sabo (1992) also summarizes records in Manitoba, Wisconsin, Ohio, Michigan, New York, New Jersey, Virginia, and Massachusetts.
Dark ibises reported for West Indies are probably Glossy Ibis (Bond 1993), but some White-faced Ibises may occur there as they wander to sw. Campeche and perhaps the e. Yucatan Peninsula.
Seeks out isolated reservoirs and irrigated fields as feeding and resting sites.
Thanks to Ryder, Ronald A. and David E. Manry. 1994. White-faced Ibis (Plegadis chihi), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/130