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 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
There are no adverse effects of Oxyura jamaicensis on humans.
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
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:
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 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 )
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
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.
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
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
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)
