Ruddy Ducks, often seen with their stiff tails pointing almost straight up, are most notable for their courtship displays. Since seasonal pair bonds form on the breeding grounds, males perform these striking displays on their territories to attract a female. Most pairs are at least socially monogamous. These ducks obtain most of their preferred food, the larvae of midges, by diving. (Brua 2002).
DISTRIBUTION. During the 1987-1992 field work seasons of the TBBA project, observers found 12 confirmed, 30 probable and 20 possible breeding sites for Ruddy Ducks. Most of these sites were on the High Plains and along the central and south coasts in the Coastal Prairies and Coastal Sand Plain regions. A few sites were also found along the lower Rio Grande River in the South Texas Brush Country (see the region map in Lockwood and Freeman ). Other confirmed breeding sites were in El Paso County in the western Trans-Pecos and on the western Edwards Plateau. In Oklahoma atlasers found one confirmed and two probable sites widely scattered across that state (Versaw 2004)l
Elsewhere North American Breeding Bird Survey (BBS) volunteers found the highest relative abundances in North Dakota (as high as 10-30 Ruddy Ducks per 40 km [25 mi] route). Other areas with relative abundances >1 were in British Columbia, Alberta, Saskatchewan, Manitoba, Minnesota, South Dakota, western Nebraska, northwest Montana, northwest Washington and the Klamath Basin of southern Oregon and northern California. Scattered breeding season presence was also found as far south as the Mexican border (Sauer et al. 2008). From there these ducks breed south through central Mexico (Howell and Webb 1995), north to northwest Canada and on the Greater Antilles. Ruddy Ducks winter .in most of the 48 contiguous United States and Mexico as well as northern Central America and the Caribbean (Stiles and Skutch 1989, Brua 2002).
SEASONAL OCCURRENCE Ruddy Ducks are common migrants and winter residents throughout Texas, arriving as early as August 8, with most present from October to April. Based on sightings of ducklings from June 4 to August 19, the breeding season lasts from at least May to August (Oberholser 1974, Lockwood and Freeman 2004). In Arizona breeding evidence was found from early April to late September (Wise-Gervais 2005).
BREEDING HABITAT. In Texas Ruddy Ducks breed in freshwater ponds lined with emergent vegetation (Oberholser 1974). In Colorado atlasers found about 35% of these ducks on wetlands with emergent or floating plants and the rest on open lakes or ponds, not surprising since 80% of confirmed evidence was of courting adults or ducklings out of the nest (Versaw 1998). In Arizona almost all breeding evidence came from wetlands fringed with emergent plants (Wise-Gervais 2005). Most Ruddy Duck nests are found in tall emergent vegetation,18-20 cm (7-8 in) above water. The female weaves live and dead pieces of surrounding plants into a basket. The average outside diameter is 31 cm (12 in), inside diameter 18 cm (7 in) and cup depth 8 cm (3 in; see photos in Harrison ).
In this basket the female usually lays 8 (range 5-15) rough, granular, white to creamy white eggs which become nest stained. The eggs, laid one per day, are incubated by the female for about 23-24 days (range 20-26). The male usually departs to molt during this period. The precocial ducklings find food for themselves and can dive for food In water 1.5 m (5 ft) deep within 24 hours after hatching. Most females abandon their brood when the ducklings are about 3 weeks old, well before the young birds can fly, about 6-7 weeks after hatching. Pairs in North America normally raise one brood per year (Harrison 1979, Brua 2002).
STATUS. In summer these ducks are uncommon (locally common in El Paso County) in Texas. Breeding records have been few (Oberholser 1974, Lockwood and Freeman 2004). BBS data show only 2 summer areas: along the Rio Grande River from El Paso to the Big Bend with a relative abundance of <1 Ruddy per 40 km (25 mu) route. The second area was near the south coast between Nueces and Cameron counties, with a relative abundance of 1-3 Ruddy Ducks per route. BBS observers did not find Ruddies on the High Plains, suggesting irregular breeding there. Data from 229 routes in North America for 1980-2007 suggest the population size has been stable during this period (Sauer et al. 2008). This stability and the size of the wintering population in Texas are hopeful signs for the future of Ruddy Ducks in this state.
Text by Robert C. Tweit (2008)
American Ornithologists’ Union. 1998. Checklist of North American birds, 7th ed. Am, Ornithol. Union, Washington, DC.
Brua, . B. 2002. Ruddy Duck (Oxyura jamaicensis), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from: http://bna.birds.cornell.edu/bna/species/696
Harrison, H. H. 1979. A field guide to western birds’ nests. Houghton Mifflin, Boston, MA.
Howell, S. N. G. and S. Webb. 1995. A guide to the birds of Mexico and northern Central America. Oxford University Press, New York.
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. University of Texas Press, Austin.
Sauer, J. R., J. E. Hines, and J. Fallon. 2008. The North American breeding bird survey, results and analysis 1966-2007. Version 5.15.2008. USGS Patuxent Wildlife Research Center, Laurel MD < http://www.mbr-pwrc.usgs.gov/bbs>
Stiles F. G. and A. F. Skutch. 1989. A guide to the birds of Costa Rica. Cornell University Press, Ithaca, NY.
Versaw, A. E. 1998. Ruddy Duck (Oxyura jamaicensis). In Colorado breeding bird atlas, pp. 102-103 (H. E. Kingery, ed.), Colorado Bird Atlas Partnership, Denver.
Versaw, A. E. 2004. Ruddy Duck (Oxyura jamaicensis). In Oklahoma breeding bird atlas, pp. 82-83 (D. L. Reinking, ed.). University of Oklahoma Press, Norman.
Wise-Gervais, C. 2005. Ruddy Duck (Oxyura jamaicensis). In Arizona breeding bird atlas. pp. 72-73 (T. E. Corman and C. Wise-Gervais, eds.), University of New Mexico Press, Albuquerque.