Ruddy ducks are omnivorous. Their diet consists primarily of aquatic invertebrates and vegetation. Their spatulate bill is used to sieve food material from mud taken in during diving. Primary plant material consumed includes angiosperm seeds and other green plants. Aquatic invertebrates constitute a fraction of the diet, depending on seasonal abundance, including mostly Crustacea and Chironomidae larvae and pupae.
Animal Foods: insects; mollusks; aquatic or marine worms; aquatic crustaceans
Plant Foods: leaves; seeds, grains, and nuts
Primary Diet: omnivore
Ruddy ducks have the ability to sink below the surface of the water. This adaptation allows them to elude predators. During breeding season they construct nests using surrounding vegetation. This provides shelter and camouflage to protect their eggs from known nest predators. Females may sometimes perform a display to distract predators away from nests. Females and nestlings are cryptically colored.
Eggs and nestlings are taken by predators such as racoons (Procyon lotor), mink (Neovison vison), American crows (Corvus brachyrhynchos), black-crowned night herons (Nycticorax nycticorax), ring-billed gulls (Larus delawarensis), and California gulls (Larus californicus). Adults are preyed on by red-tailed hawks (Buteo jamaicensis), great horned owls (Bubo virginianus), red foxes (Vulpes vulpes), mink (Neovison vison), and possibly Swainson's hawks (Buteo swainsoni). Ruddy ducks are also legally hunted in North America and Europe.
Known Predators:
Anti-predator Adaptations: cryptic
The morphology of ruddy ducks varies between sexes as well as seasonally. During the summer male ruddy ducks have rich chestnut necks and bodies. The crown, nape, and tail, which are held erect or horizontal to the water, are dark brown. Males have pure white faces, whereas females have a dark line across the face. Females and juveniles have barred bodies that lack any chesnut coloring. During the winter, male ruddy ducks resemble females. Their pure white face remains the primary distinguishing characteristic. Ruddy ducks have large, spatulate, pale blue bills. Males tend to be larger than females in weight and wingspan. Males are 142 to 154 mm from wing tip to wing tip and weigh from 540 to 795 g. Females are 135 to 149 mm from wing tip to wing tip and weigh 310 to 650 g. Body length is from 35 to 43 cm.
Male ruddy ducks have two molts. The prenuptial molt occurs in the summer months and reveals a plumage that is similar to that of females. The postnuptial molt occurs from August to October and reveals their winter plumage of bright chestnut. During this time the bill becomes bright blue as well.
Range mass: 310 to 795 g.
Range length: 35 to 43 cm.
Range wingspan: 135 to 154 mm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: male larger; sexes colored or patterned differently
The maximum lifespan of ruddy ducks in the wild is 13 years. However, in Great Britain, where the species is considered invasive, individuals rarely reach that age. According to the Global Invasive Species Database, those ducks banded and tracked in the wild rarely survive past 2 years. Those birds kept in captivity have an average lifespan of 2.4 years.
Range lifespan
Status: wild: 13 (high) years.
Average lifespan
Status: captivity: 2.4 years.
Average lifespan
Status: wild: 163 months.
Ruddy ducks inhabit permanent freshwater marshes, lakes, and ponds during their breeding season. These pools contain a considerable amount of vegetation in which these ducks hide their nests. During the winter ruddy ducks prefer shallow marshes and coastal bays.
Habitat Regions: temperate ; saltwater or marine ; freshwater
Aquatic Biomes: lakes and ponds; coastal ; brackish water
Wetlands: marsh
Other Habitat Features: estuarine
Ruddy ducks are native to North and South America. These stiff-tailed ducks nest in western and central Canada and much of the western United States as far east as the Great Lakes region and south to central Texas, throughout Baja California, and to the transvolcanic belt in Mexico. Wintering range extends throughout most of southern North America, from California through the Great Lakes region and the Atlantic coast south of southern Maine to as far south as western Guatemala and El Salvador. Ruddy ducks were introduced to England in 1960 in Gloucestershire. From there these ducks have colonized Ireland and Belgium. Ruddy ducks introduced in Europe are migratory birds from the eastern United States and Mexico. Two subspecies including Oxyura jamaicensis ferruginea and Oxura jamaicensis andina can be found in the West Indies, Columbia, and throughout the Andes Mountains.
Biogeographic Regions: nearctic (Native ); palearctic (Introduced ); neotropical (Native )
In the ecosystems in which they live, ruddy ducks act as predators on soft-bodied invertebrates such as chironomid midge larvae and crustaceans. They also eat aquatic vegetation. Ruddy ducks are preyed on by many organisms, including raccoons, mink, American crows, red-tailed hawks, and great horned owls. Ruddy ducks are used as a host by parasites that reside in their intestinal tracts such as Polymorphus obtusus and Corynosoma constrictum. They also act as hosts to tapeworms such as Hymenolepis cyrtoides and Diorchis excentrica.
Since their introduction to Europe in the 1960s, ruddy ducks have also impacted ecosystems by threatening native white-headed ducks (Oxyura leucocephala). Their continuing spread throughout Europe threatens white-headed ducks through hybridization and competition for nesting sites and food. For this reason ruddy ducks are considered invasive and are hunted.
Commensal/Parasitic Species:
In the past, ruddy ducks were hunted for the quality of their meat. There continues to be regulated sport hunting in the United States and Europe.
Positive Impacts: food
There are no adverse effects of Oxyura jamaicensis on humans.
Ruddy duck populations are considered stable throughout their range, and are considered a species of "Least Concern" on the IUCN list.
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
Ruddy ducks usually don't make many calls or other sounds. During courtship, males perform an elaborate display accompanied by a call in order to attract a mate. The voice is as follows: chuck-chuck-chuck-chuck-chur-r-r; and ip-ip-ip-ip-u-cluck; and tick, tick, tick, tickety, quo-ack; as well as chica, chica, chica, chica, quak.
Communication Channels: visual ; acoustic
Perception Channels: visual ; tactile ; acoustic ; chemical
Ruddy ducks breed seasonally, migrating to breeding grounds in late winter. According to Gooders and Boyer (1986), they form pairs in late winter. However, it is unclear whether males are monogamous or polygamous. Following arrival at the breeding grounds, males perform a striking courtship display. To attract a female the male swims around her, his tail tilted forward and neck outstretched. He then slaps his chestnut-colored chest with his bright blue bill while making his courtship call. The male also uses his tail to stand and scoot across the surface of the water. When the female is satisfied with this performance, she stretches her neck with her bill open.
Mating System: monogamous ; polygynous
Ruddy ducks breed seasonally in spring and summer months, from May to August. Following arrival at the breeding grounds, females construct nests and platforms on which males and females can rest. The nest is typically constructed just above water level and among the previous year's vegetation. Females also use these materials to form a dome over the nest to protect it from being seen by predators.
Approximately 4 weeks after arriving at the breeding grounds, females are ready to nest. Siegfried (1976a) suggests that a female's readiness to lay eggs is sometimes poorly coordinated with the availability of suitable nesting sites. This may result in egg-dropping on the ground or in other birds' nests. This is observed frequently in Oxyura jamaicensis and is known as parasitic laying. Females lay 6 to 10 white eggs which are large, relative to the size of the bird. The incubation period lasts 23 to 26 days. Young are precocial, they are brooded in the nest for their first day after hatching, after which the parents lead them from the nest. At this point young ruddy ducks are capable of diving well and of aggressive behavior towards other birds. Parents abandon their brood 20 to 30 days following hatching. These young ducks do not reach the fledgling stage, however, until 50 to 55 days after hatching.
Breeding interval: Ruddy ducks breed once yearly.
Breeding season: Breeding is from May to August.
Range eggs per season: 6 to 10.
Range time to hatching: 23 to 26 days.
Range fledging age: 50 to 55 days.
Range time to independence: 20 to 30 days.
Average age at sexual or reproductive maturity (female): 1 years.
Average age at sexual or reproductive maturity (male): 1 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; oviparous
Average eggs per season: 8.
Female ruddy ducks invest heavily in young. This is evident in the care the female takes in constructing and covering the nest, the nutritional resources invested in each egg, and the time taken in incubation. Incubation lasts 23 to 26 days and is carried out solely by the female. From the time of hatching to 2 to 4 weeks of age the female is very attentive to the brood. She remains close during feeding and also exhibits aggressive behavior when ducks of other ages approach. Females also reduce the amount of time they spend diving while the young brood dives so as to watch over and protect them.
Male ruddy ducks show little or no parental investment. Males often abandon females during the incubation period. Males that remain with females through the incubation and hatchling period show no protective behavior toward their ducklings when they are harassed by other avian species.
Parental Investment: precocial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female)
A small (15-16 inches), oddly-shaped duck, the male Ruddy Duck in summer is most easily identified by its chestnut-brown body, black cap, white cheeks, and blue bill. In winter, the male loses much of its color, becoming gray-brown above and mottled gray below with a gray bill while retaining its solid white cheeks. Females are similar to winter males, but have gray-brown cheeks. This species is one of several “stiff-tailed” ducks, all of which have short, stiff tails which are often held erect. The Ruddy Duck breeds widely in the western United States, southwestern Canada, and western Mexico. Smaller numbers breed further east in the Great Lakes region and along the St. Lawrence River. In winter, this species vacates northern portions of its range, and may be found at lower elevations across the U.S. and most of Mexico. Other non-migratory populations occur in Central America and in the West Indies, and an introduced population breeds in Britain. Ruddy Ducks breed in a variety of freshwater wetlands, primarily those surrounded by grassland or prairie. In the winter, this species may be found in freshwater wetlands as well as in brackish bays and estuaries. Ruddy Ducks primarily eat small invertebrates, including insects and crustaceans. One of many species of ducks which dive while foraging for food, Ruddy Ducks may be observed submerging themselves to feed on invertebrates in the water or on the bottom. Although Ruddy Ducks are quite agile while in the water, this species is among the least terrestrial ducks in its range, being almost entirely incapable of walking on land. Ruddy Ducks are primarily active during the day.
A small (15-16 inches), oddly-shaped duck, the male Ruddy Duck in summer is most easily identified by its chestnut-brown body, black cap, white cheeks, and blue bill. In winter, the male loses much of its color, becoming gray-brown above and mottled gray below with a gray bill while retaining its solid white cheeks. Females are similar to winter males, but have gray-brown cheeks. This species is one of several “stiff-tailed” ducks, all of which have short, stiff tails which are often held erect. The Ruddy Duck breeds widely in the western United States, southwestern Canada, and western Mexico. Smaller numbers breed further east in the Great Lakes region and along the St. Lawrence River. In winter, this species vacates northern portions of its range, and may be found at lower elevations across the U.S. and most of Mexico. Other non-migratory populations occur in Central America and in the West Indies, and an introduced population breeds in Britain. Ruddy Ducks breed in a variety of freshwater wetlands, primarily those surrounded by grassland or prairie. In the winter, this species may be found in freshwater wetlands as well as in brackish bays and estuaries. Ruddy Ducks primarily eat small invertebrates, including insects and crustaceans. One of many species of ducks which dive while foraging for food, Ruddy Ducks may be observed submerging themselves to feed on invertebrates in the water or on the bottom. Although Ruddy Ducks are quite agile while in the water, this species is among the least terrestrial ducks in its range, being almost entirely incapable of walking on land. Ruddy Ducks are primarily active during the day.
The ruddy duck (Oxyura jamaicensis) is a duck from North America and one of the stiff-tailed ducks. The genus name is derived from Ancient Greek oxus, "sharp", and oura, "tail", and jamaicensis is "from Jamaica".
The ruddy duck was formally described in 1789 by the German naturalist Johann Friedrich Gmelin in his revised and expanded edition of Carl Linnaeus's Systema Naturae. He placed it with the other ducks, geese and swans in the genus Anas and coined the binomial name Anas jamaicensis.[2] Gmelin based his description on the "Jamaica shoveler" that had been described in 1785 by the English ornithologist John Latham from a specimen that he had received from Jamaica.[3] The ruddy duck is now placed with five other species in the genus Oxyura that was introduced in 1828 by the French naturalist Charles Lucien Bonaparte.[4][5] The genus name is derived from Ancient Greek oxus, meaning "sharp", and oura meaning "tail". The specific epithet jamaicensis means "from Jamaica".[6] The Andean duck was formerly considered to be conspecific with the ruddy duck but with the two species split, the ruddy duck is monotypic: no subspecies are recognised.[5]
These are small, compact ducks with stout, scoop-shaped bills, and long, stiff tails they often hold cocked upward. They have slightly peaked heads and fairly short, thick necks. Male ruddy ducks have blackish caps that contrast with bright white cheeks. In summer, they have rich chestnut bodies with bright blue bills. In winter, they are dull gray-brown above and paler below with dull gray bills. Females and first-year males are brownish, somewhat like winter males but with a blurry stripe across the pale cheek patch. In flight, ruddy ducks show solidly dark tops of the wings.[7]
Their breeding habitat is marshy lakes and ponds. They nest in dense marsh vegetation near water. The female builds the nest out of grass, locating it in tall vegetation to hide it from predators. A typical brood contains 5 to 15 ducklings.[10] Pairs form each year.
They are migratory and winter in coastal bays and unfrozen lakes and ponds.
These birds dive and swim underwater. They mainly eat seeds and roots of aquatic plants, aquatic insects and crustaceans.
Ruddy ducks were imported into the UK in 1948 by conservationist Sir Peter Scott.[11] As a result of escapes from wildfowl collections in the late 1950s, they became established in Great Britain, from where they spread into Europe. By the year 2000, the population had increased to around 6,000 individuals. This duck's aggressive courting behavior and willingness to interbreed with the endangered native white-headed duck (Oxyura leucocephala), of southern Europe, caused concern amongst Spanish conservationists. Due to this, a controversial scheme to extirpate the ruddy duck as a British breeding species started; there have also been culling attempts in other European countries.[12]
By March 2012 a culling program in the UK, supported by the RSPB, had killed 6,500, at a cost of £5m (£769 per bird).[13] In 2003 the BBC had reported the cost of killing each bird at £915.[12] In 2012 Lee Evans, founder of the British Birding Association, claimed "The cull cannot succeed now. There are hundreds of ruddy ducks on the continent which will not be killed so the birds will continue to breed. There's never been any proof, anyway, that the British population has ever interbred with the Spanish ducks".[13] By early 2014, the cull had reduced the British population to about 20–100, down from a peak of about 5,500 in 2000.[14] According to Animal Aid, in the UK the cost of hunting down the last few ruddy ducks was £3,000 per bird. They advised "If you see one, don’t tell anyone. Even bird groups will tell the authorities and those birds may be killed".[15]
In Europe, the Ruddy duck is included since 2016 in the list of Invasive Alien Species of Union concern (the Union list).[16] This implies that this species cannot be imported, bred, transported, commercialized, or intentionally released into the environment in the whole of the European Union.[17]
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Oxyura jamaicensis - MHNT The ruddy duck (Oxyura jamaicensis) is a duck from North America and one of the stiff-tailed ducks. The genus name is derived from Ancient Greek oxus, "sharp", and oura, "tail", and jamaicensis is "from Jamaica".
