RING-NECKED DUCK

Aythya collaris


Ring-necked Ducks are the shallowest divers of all North American diving ducks, preferring water as shallow as 2 m (7 ft) deep. At this depth these ducks can forage within emergent and submerged or floating plants on stems, roots and seeds of aquatic vegetation and invertebrates. These omnivorous feeders are also seen occasionally "tipped-up" like dabbling ducks, foraging in very shallow water. Ring-necked Ducks are most common in the breeding season in subarctic North America, although at relatively low densities in river deltas, taiga, boreal forests, aspen parklands and to a lesser extent, prairie regions. These ducks arrive with pairs already formed, either in winter or during spring migration (Hohman and Eberhardt 1998).

DISTRIBUTION. During the 1987-1992 field work seasons of the TBBA project, atlasers found 2 probable breeding sites for Ring-necked Ducks in latilong-quad 32095-F8 in east Texas and a possible site (31104-H6) in the Trans-Pecos (see the region map in Lockwood and Freeman [2004]). North American Breeding Bird Survey (BBS) observers did not record this duck in Texas (Sauer et al. 2008). In Arizona and Oklahoma, atlasers did not find breeding evidence for these ducks (Reinking 2004, Corman and Wise-Gervais 2005).


BBS observers did find Ring-necked Ducks in western Canada and across southern regions of that country east to Newfoundland and northern New England. These observers also reported Ring-necks from northern Wisconsin and Minnesota, extending west to the Pacific Coast and south to extreme northern California and southern Utah and Colorado (Sauer et al. 2008). Outside the BBS range these ducks also breed in northwest Canada. Most Ring-necks winter inland in shallow waters through the southern and western United States and Mexico. Some also winter along coasts of these countries and on islands of the northern Caribbean (Howell and Webb 1995, Hohman and Eberhardt 1998).

SEASONAL OCCURRENCE. Ring-necked Ducks are uncommon to locally common migrants and winter residents in Texas, arriving as early as September 3. Most of the population is present from mid-October to mid-April. Ring-necks are rare in the western half of the state in summer with no nesting confirmed (Oberholser 1974, Lockwood and Freeman 2004). In Colorado the presence of fledged young from June 13 to August 23 suggests a breeding season starting at least as early as April (Versaw 1998).



BREEDING HABITAT. In Colorado, the closest state to Texas where breeding habitats have been quantified, atlasers found most fledged Ring-necked Ducks on lakes edged with rooted vegetation at elevations from about 2100-3000 m (7000-10,000 ft).  These ducks, in contrast to other North American diving ducks, are usually found on water less than 2 m (7 ft) deep with submerged vegetation. Hens place their nests on hummocks, sedge meadows and waterside grasslands, rarely overwater in emergent vegetation. The nests are generally within 14 m (45 ft) of permanent water. Nests in sedge meadows offer the best protection from predation by raccoons, a major threat to nests of these ducks (Versaw 1998).

A weak platform of vegetation is built from plant materials around the nest site before egg-laying starts. After the 3rd or 4th egg is laid, one per day, a bowl is built around the eggs. The completed clutch is usually 8-9 (range 5-14) smooth, olive-gray to olive-brown eggs, indistinguishable  from those of Lesser Scaup (A. affinis). The hen incubates the eggs (her mate leaves after the clutch is complete) for 25-29 days. The precocial ducklings leave the nest the day after hatching to follow their mother to water where they feed mostly on the surface for the first week, being brooded by the hen while resting. As the young develop they dive more frequently. Parental protection ends when the female abandons the young as much as 3 weeks before the ducklings are able to fly, 7-8 weeks after hatching. Only one brood is reared per season (Harrison 1979, Hohman and Eberhardt. 1998).


STATUS. As Ring-necked Ducks are rare in Texas in summer, the lack of confirmed nestings is not surprising. Since some Ring-neck pairs form on the wintering grounds or at migration stopovers, courtship behavior can cause problems for atlasers. (Hohman and Eberhardt 1998, Lockwood and Freeman 2004). Despite the danger to these ducks of ingestion of lead shot or overharvesting (Hohman and Eberhardt 1998), North American BBS data for 1980-2007 strongly indicate a reassuring +3.3% annual population trend (Sauer et al. 2008). This North American trend suggests Ring-necked Ducks will continue to be winter residents in Texas.

Text by Robert C. Tweit (2008)

Literature cited.
Corman, T. E. and C. Wise-Gervais, eds. 2005. Arizona breeding bird atlas. University of New Mexico Press, Albuquerque.

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

Hohman, W.  L. and R. T. Eberhardt. 1998. Ring-necked Duck (Aythya collaris), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from: http://bna.birds.cornell.edu/bna/species/329

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.

Reinking, D. L., ed. 2004. Oklahoma breeding bird atlas. University of Oklahoma Press, Norman.

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>

Versaw A. E. 1998. Ring-necked Duck (Aythya collaris). In Colorado breeding bird atlas, pp. 92-93 (H. E. Kingery, ed.), Colorado Bird Atlas Partnership, Denver.