Ring-necked ducks are mainly a migratory species. During the breeding season, it can be found as far north as southern and central Alaska. Other populated portions of North America include the central Canadian regions as well as Minnesota, Maine, and some smaller portions of the northern United States. A few areas, including parts of Washington, Idaho, and other central western states of the United States are home to ring-necked ducks year-round. The species nests most often in the northern regions of Alberta, Saskatchewan, Minnesota, Wisconsin, Michigan, the central regions of Manitoba, and the southern regions of Ontario and Quebec.

These ducks prefer to spend their winters in the southern regions of New England and the Great Plains in the United States, the southern regions of British Columbia in Canada, and areas farther south including Mexico, Costa Rica, Jamaica, and Puerto Rico. During the winter, small numbers have been found in Venezuela and Trinidad. Small numbers have also been recorded in Panama, Bermuda, the Bahamas, Cuba, and the Dominican Republic.

This species is a vagrant in the north African countries of Algeria and Morocco, Japan, and the European nations of Austria, Belgium, Denmark, Faroe Islands, Finland, France, Germany, Iceland, Ireland, the Netherlands, Norway, Poland, Portugal, Spain, Sweden, Switzerland, and the United Kingdom.

Biogeographic Regions: nearctic (Native ); neotropical (Native )

occurs (regularly, as a native taxon) in multiple nations

Canada

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

United States

Origin: Native

Regularity: Regularly occurring

Currently: Present

Confidence: Confident

Type of Residency: Year-round

Global Range: (>2,500,000 square km (greater than 1,000,000 square miles)) BREEDS: southeastern and east-central Alaska, central British Columbia eastward through northern Saskatchewan to Newfoundland, south to northeastern California, southeastern Arizona, southern Colorado, Iowa, Illinois, Pennsylvania (formerly), northern New York, Massachusetts. WINTERS: southeastern Alaska, southwestern U.S., southern Illinois, and Massachusetts south through Mexico to Panama, Grenada, West Indies; rarely Hawaii. (AOU 1983). In the U.S., the highest winter densities occur in eastern New Mexico (Bitter Lake refuge), the Mississippi River in Mississippi, Lake Isom and Reelfoot refuges (Missouri-Tennessee), the Florida panhandle (St. Marks refuge), eastern Texas panhandle, and southern San Joaquin Valley in California (Root 1988).

Ring-necked ducks are small to medium in size. Males are slightly larger than females. Total length of males falls between 40 and 46 cm, and between 39 and 43 cm for females. The mass of males falls between 542 and 910 g and in females is usually between 490 and 894 g. Seasonal body mass fluctuations are common and cause overlaps between the sexes. Ring-necked ducks have a wingspan of 63.5 cm.

Defining characteristics of adult males include a black head, neck, breast, and upper portions, with a whitish gray belly and flanks. On the folded wing is a distinct white wedge on the shoulder that extends upwards. Adult females are grayish brown, with the darkest coloration on top of the head. They are pale on the front of their heads, chins, and throats. Eyes are bordered by a white ring, and females appear overall duller than males. The species is similar in profile to other diving ducks, but with a tail that is somewhat longer and a head that contains a short crest, which gives it its distinct peaked or angular appearance. Immature Aythya collaris appear similar to the adults, but are more dull in coloration.

In the winter, adults and ducklings experience changes in physical appearance. The body mass of both increases, but adults show a more drastic change from their original mass.

Range mass: 490 to 910 g.

Range length: 39 to 46 cm.

Average wingspan: 63.5 cm.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry

Sexual Dimorphism: male larger; sexes colored or patterned differently; male more colorful

Length: 43 cm

Weight: 730 grams

• Terrestrial
• Freshwater

The habitat of Aythya collaris varies seasonally. During the breeding and post-breeding season the species prefers freshwater wetlands, usually fens, bogs, and marshes, all of which are quite shallow. The pH of these wetlands is usually near neutral because the aquatic invertebrates these ducks, especially females during the breeding season, consume do not fair well under highly acidic conditions. Areas commonly inhabited have a high level of organic material within. There is usually abundant vegetation, both floating and submerged, with open water zones found throughout as well.

During the winter, the species utilizes a huge array of wetlands, but is rarely found in areas with high salinity levels or depths >1.5 meters. Floodplains of rivers, fresh and brackish parts of estuaries, and shallow inland lakes and marshes are common habitats. These shallow areas are also rich with moist soil vegetation. Aythya collaris has also been found in flooded agricultural lands, aquaculture ponds, and managed freshwater impoundments.

When nesting, ring-necked ducks prefer to live in smaller, shallower wetlands. Because these areas are relatively more abundant than the large open waters preferred by several other duck species, Aythya collaris often has a relatively higher rate of nesting success compared to those species.

Habitat Regions: temperate ; tropical ; terrestrial ; freshwater

Terrestrial Biomes: savanna or grassland

Aquatic Biomes: lakes and ponds; rivers and streams; coastal ; brackish water

Wetlands: marsh ; bog

Other Habitat Features: agricultural ; riparian ; estuarine

Comments: Marshes, lakes, rivers, swamps, especially in wooded areas. Winters primarily on freshwater and brackish situations of larger lakes, rivers, and estuaries (AOU 1983); prefers deep open water (Stiles and Skutch 1989). Sleeps by day near emergent vegetation by lakeshores (Madge and Burn 1988). Birds close to the coast may spend their nights out at sea but come in at dawn to feed in fresh water (Root 1988). In Minnesota, ducklings spent most of time in open water, used islands of decayed vegetation for resting (Wilson Bull. 104:472-484). Nests at margins of small ponds, sloughs, bogs, and marshes.

Non-Migrant: No. All populations of this species make significant seasonal migrations.

Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).

Locally Migrant: Yes. At least some populations of this species make annual migrations of over 200 km.

Migrates northward in March-April, southward usually mid-September to late November (Terres 1980). Arrives in Costa Rica in late October or November, departs January-March, depending on water levels.

In winter, shallow bodies of water such as flood plains and the margins of lakes and bogs are filled and plants requiring moist soils or that float on the water's surface abound. Spring migrants locate food in these flooded areas. Members of this species eat mainly plant seeds and tubers from the moist soil and feed on aquatic invertebrates as well. Occasionally they prey on insects. Nesting adults and offspring forage on aquatic plant species like pondweed, coontail, cow lily, and water milfoil. Fall migrants obtain food from shallow lakes and rivers that have wild rice, American wild celery, or arrowheads.

Aythya collaris feeds mainly by shallow diving, but also collecting items on or near the surface of the water. Its preference for obtaining food from shallow waters, even though it can dive, can be attributed to the high level of biomass closer to the surface. This species is more of an opportunistic and generalized feeder than others in the same genus. The species usually consumes food during dives, but some food is brought back to the surface to be processed, such as removing food from the shell of gastropods and removing protective layers from insects.

Prey ranges in size from less than 0.1 mm to 5 cm. Invertebrate consumption is the greatest in young, and composes 98% of the total diet. Females tend to eat more invertebrates than usual during the breeding season, a time when more dietary protein is necessary. The males sometimes exhibit slight increases in invertebrate consumption, but the change is not as significant as in females. Some common prey of ring-necked ducks includes aquatic earthworms, snails, clams, dragonflies, and caddis flies.

Animal Foods: insects; mollusks; terrestrial worms; aquatic or marine worms; aquatic crustaceans

Plant Foods: leaves; roots and tubers; seeds, grains, and nuts

Primary Diet: herbivore (Folivore )

Comments: Plant material important: tubers, leaves, rootstocks, and seeds of aquatic plants (pondweeds, algae, sedges, grasses, smartweeds, etc.). Also eats aquatic invertebrates, espec. in summer. Downy young: insects, snails, sponges, etc.; also seeds and other plant material.

Aythya collaris serves as a host to parasites Clostridium botulinum and Pasteurella multocida, which cause avian botulism and avian cholera, respectively. The parasites are most prevalent in California, but have been found to cause botulism and cholera throughout the Pacific, central, and Mississippi waterways. Bacterial diseases which cause mortality in these ducks include coccidiosis, aspergillosis, and avian tuberculosis. Ring-necked ducks can be infected by a wide array of parasites.

Ring-necked ducks are both herbivores and predators on aquatic invertebrates and have a significant impact on those populations where they forage. Eggs, young, and adult ring-necked ducks are a source of food for many predators.

Commensal/Parasitic Species:

• Avian botulism (Clostridium botulinum)
• Avian cholera (Pasteurella multocida)

In Maine, examples of predators on adult Aythya collaris include red fox, raccoons, Northern harriers, great horned owls, American mink, bald eagles, peregrine falcons, and common snapping turtles. There are also many organisms which prey on the eggs of ring-necked ducks, major predators include American mink, crows, ravens, raccoons, fox, muskrat, skunks, and domestic dogs. Ducklings may fall prey to large, predatory fish such as pike and bass.

In order to prevent predation at the nest, some females will defecate on eggs to cover their enticing scent. Some ducks fake injury when disturbed. When broods are attacked from below the water, the mother uses her wings and feet to attack while the ducklings scatter away. Adults and young use their diving ability to try and escape aerial predation.

Known Predators:

• Red fox (Vulpes vulpes)
• Raccoons (Procyon lotor)
• Northern harriers (Circus cyaneus)
• Great horned owls (Bubo virginianus)
• American mink (Neovison vison)
• Bald eagles (Haliaeetus leucocephalus)
• Peregrine falcons (Falco peregrinus)
• Common snapping turtles (Chelydra serpentina)
• Muskrats (Ondatra zibethicus)
• Skunk (Mephitis mephitis)
• Domestic dogs (Canis familiaris)
• Pike (Esox lucius)
• Bass (Micropterus)
• Crows (Corvus brachyrhynchos)
• Ravens (Corvus corax)

Usually widely dispersed in winter, but concentrations of several thousand not uncommon (Terres 1980). Usually in flocks (Stiles and Skutch 1989). In Maine, daily survival rate of duckling was reduced in low-pH wetlands (Mcauley and Longcore, 1988, J. Wildl. Manage. 52:169-176).

Aythya collaris is a vocal animal, but these vocalizations have not been studied in depth. The male "kink-neck" call is emitted during the courtship displays of neck stretching and head throwing. During courtship displays or when curious, the female makes a soft purring growl. When alarmed or during flight in the nesting season, the female may make a high pitched growl. Alarm calls given to a brood by the mother are short and soft 'cut-cut-cut' noises.

Ring-necked ducks rely heavily on visual communication during courtship displays. Males attract mates through various displays including neck stretching, head throwing, and nod swimming. Females respond to these displays using head bobbing. Successfully paired mates perform post-copulatory swimming, where the male and female swim side by side with heads held high. Like all birds, ring-necked ducks perceive their environments through visual, auditory, tactile and chemical stimuli.

Communication Channels: visual ; acoustic

Other Communication Modes: duets

Comments: Most active early morning and evening (Madge and Burn 1988).

Using estimates from band recoveries, it has been shown that the annual survival rates of male ring-necked ducks is greater than that of the females, 63-69% versus 48-58% respectively. A possible hypothesis for this is that females alone practice parental behavior are therefore put in dangerous positions when having to defend their young, as well as themselves, from predators. The oldest banded ring-necked duck was recovered twenty years after banding, and given an age estimate of just over 20 years.

Range lifespan

Status: wild: 20.3 (high) years.

Average lifespan

Status: wild: 245 months.

Aythya collaris is a primarily monogamous species that forms pair bonds. This occurs during spring migration, from March until April.

Reproductive behaviors are similar to that of other species of diving birds and include mutual displays. An example of this includes a neck stretch, in which the head is raised to full neck extension with the bill pointed forward and slightly elevated. This behavior can occur both in or out of the water. Drinking or bill-dipping, in which the bill is lowered into the water without raising the head, and post-copulatory swimming, where the male and female swim side by side with heads held high, are two other examples of mutual mating displays.

Male only displays include a head throw (the head is brought back until the throat is part vertical), nod swimming (a rapid swim while the head nods back and forth with the crest fully extended) and preening behind the wing (the preening of the scapular region with the wing partially extended).

Extra-pair copulations are very uncommon but have been seen in northwestern Minnesota during a drought year. This happened at a time when the body masses of returning birds, food availability, and breeding participation of the females were much lower than they had been in previous years.

Mating System: monogamous

The breeding season of ring-necked ducks occurs between the months of May and early August, with peak activity from mid-May until mid-July. Pair bonds are formed during spring migration and remain until late June or early July.

In selecting a site for nesting, pairs swim along the open waters of wetlands. The females swim into flooded vegetation looking for suitable sites, while the male keeps lookout nearby. They search for a dry or semidry site situated near water, often with clumps of vegetation. The female constructs the nest. After 3 to 4 days of nest building, the nest resembles a bowl, and by day 6 the nest is strong with a clear shape to it. Occasionally nest construction doesn't begin until the 3rd or 4th egg is laid. Nests are lined with bent grasses and downy feathers.

Female ring-necked ducks lay between 6 and 14 eggs per season, with an average between 8 and 10. The eggs are ovular in shape and range in color from olive-gray to olive-brown, possessing a smooth surface texture. Incubation starts after the clutch is completed, and the beginning of incubation is the first day the female remains at the nest overnight. Incubation generally lasts 26 or 27 days. The precocial chicks hatch weighing between 28 and 31 g. Chicks are covered in downy feathers and are capable of following parents and feeding themselves soon after hatching. Young fledge after 49 to 56 days and reach independence 21 to 56 days after fledging. Reproductive maturity is achieved quite quickly in both sexes, with both breeding in their first year, although young ducks may shy away from breeding some years due to lower availability of nesting areas.

Breeding interval: Ring-necked ducks produce one brood per season, but may produce another clutch if initial nest is destroyed.

Breeding season: Ring-necked ducks breed from May to early August (peak activity from mid-May until mid-July).

Range eggs per season: 6 to 14.

Average eggs per season: 8 to 10.

Range time to hatching: 25 to 29 days.

Average time to hatching: 26 to 27 days.

Range birth mass: 28.4 to 31.0 g.

Range fledging age: 49 to 56 days.

Range time to independence: 21 to 56 days.

Average age at sexual or reproductive maturity (female): 1 years.

Average age at sexual or reproductive maturity (male): 1 years.

Key Reproductive Features: seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); fertilization

Average eggs per season: 9.

Parental care of offspring is exhibited by females only, but males aid indirectly in the production of offspring by attending to the nutritional needs of their mates while they are in the laying stage of reproduction. The young emerge from the egg without their mother's aid, after which she crushes the shells and proceeds to bury them, carrying them away from the nest, or ingesting them. Aythya collaris young gain the ability to dive about 48 hours post hatching, but count on surface foods mostly for the first week of life, and do not count on their mothers to feed them.

The mother generally remains with the young until fledging, but sometimes leaves earlier if the young have begun to develop the contour feathers necessary for flight. Maternal care is mostly protective. After the mother leaves, broods have been shown to spend more time feeding and less time resting, probably due to the loss of the mother's vigilant eye.

Parental Investment: precocial ; female parental care ; pre-fertilization (Provisioning, Protecting: Male, Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Protecting: Female); pre-independence (Protecting: Female)

Clutch size is 6-14 (usually 8-10). Incubation, by female, lasts 25-29 days (Terres 1980). Young are tended by female, can fly about 49 days after hatching.

This species has an extremely large range and is not declining or fluctuating in population size. Ring-necked duck habitats are currently healthy and abundant. The species is considered by the IUCN Red List to be of least concern. However, lead poisoning is common in some areas due to the ingestion of lead pellets used by hunters. In 1991 the United States called for a mandatory switch to non-toxic shot made of steel or bismuth and tin. A study done in 1996 of the Mississippi waterways found that 12.7% of 749 ring-necked ducks surveyed contained the non-toxic pellets, and of those 55% ingested both non-toxic and lead forms at some point. Also, there is a huge threat to ducklings, as they spend the majority of their time foraging, that may ingest lead as well as nontoxic pellets. Lead levels continue to be a problem years after the switch. Also, these ducks are hunted in other countries that still permit the use of lead shot.

The acidification of habitats can kill off the invertebrates Ayatha collaris relies on heavily during the breeding season. The potential adverse effects of this have not been studied in depth.

US Migratory Bird Act: protected

US Federal List: no special status

CITES: no special status

State of Michigan List: no special status

IUCN Red List of Threatened Species: least concern

Canada

Rounded National Status Rank: N5N,N5B : N5N: Secure - Nonbreeding, N5B: Secure - Breeding

United States

Rounded National Status Rank: N5B,N5N : N5B: Secure - Breeding, N5N: Secure - Nonbreeding

Rounded Global Status Rank: G5 - Secure

There is no direct negative effect on humans but because of the lead some ducks swallow due to human hunting (before the switch to nontoxic pellets) the possibility for biomagnification exists. That is, if this species ingests lead shot, and is then eaten by another organism such as a bass or pike, the next higher predator to consume the bass or pike is going to get a larger dosage of lead in their system. This higher organism could be an eagle or falcon, but could very well be a human being.

Ring-necked ducks are economically important in the hunting and game industry. They are widely hunted across Canada and the United States.