AnimaliaHighest rank in taxonomy. Groups all life into domains: Animalia, Plantae, Fungi, etc.IUCN LCInternational Union for Conservation of Nature — the world authority on species extinction risk, using standardized criteria. — Least Concern — widespread and abundant; not at immediate risk of extinction.In ProgressCurrent stage of this record in the editorial review workflow. Recent Sighting
Aythya collaris
Ring-necked Duck
(Donovan, 1809)
Detailed Texts Multi-lang
A medium-sized diving duck with a distinctive angular or peaked head profile. Breeding males have a shiny black head, breast, and back, pale grey flanks, and a conspicuous white vertical wedge on the shoulder. Females are soft greyish-brown with a pale face, a white eye-ring, and a pale stripe extending behind the eye. Both sexes feature a prominent white band near the tip of a slate-grey bill.
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Anonymous Curator
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Under Review
Last modified by
Julia Trouin
TaxonomyBiological classification ranks placing this species within the tree of life, from Kingdom down to Genus.
PhylumRank below Kingdom. Groups organisms sharing a fundamental body plan (e.g., Chordata = vertebrates and some invertebrates).Chordata
ClassRank below Phylum. Subdivides by structural traits (e.g., Mammalia, Aves, Reptilia, Insecta).Aves
OrderRank below Class. Groups related families sharing common ancestry (e.g., Carnivora, Primates).Anseriformes
FamilyRank below Order. Groups closely related genera (e.g., Felidae = cats, Canidae = dogs).Anatidae
GenusRank just above Species. The first word in the two-part binomial scientific name.Aythya
Taxonomic AuthorityThe scientist who first formally described and published this species, followed by the year of publication.(Donovan, 1809)
Record Completeness
96%Coming soon
Ecology & StatusHow this species lives: habitat preferences, diet, behavior, population status, and role in its ecosystem.
OriginWhether the species is native (evolved here), endemic (found only here), or introduced by human activity.
Native
Population TrendDirection of change in population size over time: increasing, stable, decreasing, or unknown.
Increasing
Breeding SeasonTime of year when this species typically reproduces or flowers.
Year Round
Trophic RolePosition in the food chain: producer, herbivore, carnivore, omnivore, decomposer, or parasite.
Omnivore
Recent SightingsWhether this species has been observed in the wild in Costa Rica within recent years.
Yes
Habitat SummaryOverview of the specific ecosystems and environments where this species is found in Costa Rica. Multi-lang
Inhabits shallow freshwater wetlands, including wooded ponds, bogs, marshes, beaver ponds, and slow-moving rivers. Unlike other diving ducks that favor wide, deep open waters, this species prefers smaller bodies of water with abundant emergent or floating vegetation.BehaviourDaily activity patterns, movement, territory use, foraging style, and seasonal behavioral changes. Multi-lang
An agile diving duck that is highly migratory, breeding in northern wetlands and wintering in warmer southern areas. While they can dive deeply to feed, they often forage in shallower waters than other divers, sometimes even tipping up like dabbling ducks. Flight is rapid, with shallow, continuous wingbeats. Breeding vocalizations from males include a low hiss, while females produce a harsh growling 'scaup' call.Social ActivitySocial structure: whether the species is solitary, paired, or colonial; hierarchy and communication. Multi-lang
Highly social during the non-breeding season and winter migration, frequently congregating in large flocks numbering hundreds or even thousands of individuals on staging lakes. During the nesting phase, large aggregations disband as pairs seek strict territorial isolation.Feeding GuildWhat the species eats, how it forages or hunts, and its role as a consumer in the food web. Multi-lang
Aquatic diving omnivore.Trophic Chain DetailsSpecific interactions in local food webs: prey species, predators, competitors, and scavengers. Multi-lang
Feeds on a balanced, omnivorous diet that shifts seasonally. During the breeding season, they target aquatic invertebrates such as dragonflies, caddisfly larvae, midges, snails, and earthworms to satisfy high protein needs. In winter, they consume seeds, tubers, and leaves of submerged vegetation like pondweeds and wild rice. Predators include bald eagles, large owls, foxes, and raccoons.Reproductive BehaviourMating strategies, courtship displays, nesting or spawning behavior, and parental care. Multi-lang
Forms seasonal monogamous pairs during spring migration. The female selects a well-concealed site in dense emergent vegetation over shallow water, building a shallow platform cup nest made of grasses and sedges, lined with down. She lays 6 to 14 olive-buffered eggs and is the sole incubator, while the male abandons the territory shortly after incubation begins.Physical Measures
Length (cm)
39.0 - 46.0 cm
Weight (Grams)
500 g - 910 g
Offspring per cycleTypical number of young (live births, eggs, or seeds) produced by one adult in a single reproductive event or breeding season.6 - 14
Sexual DimorphismObservable physical differences between males and females of the same species (e.g., size, coloration, features).Yes
Lifespan
Sexual MaturityAge at which the individual becomes capable of reproducing for the first time.
10 - 12 Months
Gestation / IncubationDuration from fertilization to birth (mammals) or to hatching (egg-laying species).
25 - 29
Lifespan EstimatedExpected duration of life from birth to natural death under wild conditions.
Males5 - 14 Years
Females5 - 14 Years
Sexual DimorphismPhysical differences in size, coloration, or morphology between males and females of this species.
Males Multi-lang
The breeding male features a glossy black head with a subtle purple or green iridescent sheen, a solid black breast and back, and pale grey flanks. A clean, white vertical band stands out distinctly on the forward flank. The bill is dark slate-grey bordered by a white line at the base and a prominent white ring near the tip, and the eyes are intense golden-yellow.
Females Multi-lang
The female is uniform brownish-grey, designed for nesting camouflage. She has a distinctive pale grey face with a thin, sharp white eye-ring and a narrow post-ocular pale stripe. Her bill is duller slate-grey with a less intense white band near the tip, and her eyes vary from dark brown to a soft, pale brownish-yellow.
Evolutionary AdaptationsInherited traits and behaviors that improve the species' survival and reproduction in its specific environment. Multi-lang
Strong, specialized legs positioned slightly more centrally than in other typical diving ducks, allowing for easier and more efficient vertical takeoffs directly from the water surface without a long running start.
A broad, flattened bill equipped with fine internal lamellae acting as a high-precision sieve to filter aquatic seeds and macroinvertebrates from muddy lake bottoms.
Main ThreatsDocumented pressures reducing the population: habitat loss, hunting, disease, climate change, and invasive species. Multi-lang
Ingestion of spent lead shot from historical hunting activities on lakebeds, causing severe lead poisoning (saturnism) that impairs neurological and digestive systems.
Interesting FactsSurprising or notable facts that highlight what makes this species unique or ecologically important. Multi-lang
The common name 'Ring-necked' is notoriously misleading in the field; it references a faint, dark cinnamon collar on the male's black neck that is virtually invisible unless examining a specimen in hand under perfect lighting.