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
Arenaria interpres
Ruddy Turnstone
(Linnaeus, 1758)
Detailed Texts Multi-lang
A medium-sized, stocky shorebird with a uniquely robust, wedge-shaped bill slightly upturned at the tip, and short, bright orange legs. In breeding plumage, it shows a striking 'harlequin' pattern, characterized by a boldly calico-mottled back of rich chestnut-rufous and black, a clean white belly, and a complex black-and-white mask across the head and breast. In non-breeding winter plumage, the bird becomes much duller, displaying dark greyish-brown upperparts and a dark breast band. In flight, it reveals an intricate, multi-banded pattern of white and dark stripes across its back, wings, and tail.
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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).Charadriiformes
FamilyRank below Order. Groups closely related genera (e.g., Felidae = cats, Canidae = dogs).Scolopacidae
GenusRank just above Species. The first word in the two-part binomial scientific name.Arenaria
Taxonomic AuthorityThe scientist who first formally described and published this species, followed by the year of publication.(Linnaeus, 1758)
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.
Decreasing
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.
Carnivore
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
Breeds on the rocky, gravelly coastlines and open stony moss-tundra of the high Arctic regions. Outside of the breeding season, it has a global coastal distribution, strictly favoring rocky shorelines, wave-washed reefs, pebble beaches, rock jetties, and coral flats, entirely bypassing fine sandy mudflats unless heavily strewn with kelp or shells.BehaviourDaily activity patterns, movement, territory use, foraging style, and seasonal behavioral changes. Multi-lang
A highly migratory, strictly coastal, diurnal bird. Foraging involves a highly active, aggressive routine of routing through beach debris, flipping stones, and routing kelp beds. While highly aggressive and strictly territorial on their arctic nesting territories, they are gregarious and feed in tightly packed, noisy flocks during the winter months, often sharing rocky roosts with Purple Sandpipers or Surfbirds.Social ActivitySocial structure: whether the species is solitary, paired, or colonial; hierarchy and communication. Multi-lang
Demonstrates complex social variations; highly unsocial, aggressively pugnacious, and territorial when establishing tundra nesting boundaries. In sharp contrast, they become immensely gregarious outside of breeding, flying and roosting in tightly integrated flocks, and establishing clear social linear hierarchies based on plumage brightness during competitive group feeding.Feeding GuildWhat the species eats, how it forages or hunts, and its role as a consumer in the food web. Multi-lang
Carnivore (shoreline invertivore and opportunistic egg predator specialized in stone-flipping and debris routing).Trophic Chain DetailsSpecific interactions in local food webs: prey species, predators, competitors, and scavengers. Multi-lang
Acts as an specialized secondary and tertiary consumer in intertidal shoreline zones. Its extensive, generalist diet includes beach fleas, amphipods, barnacles, small crabs, marine worms, snails, and the eggs of horseshoe crabs, alongside occasional carrion or birds' eggs. They are apex predators within their micro-niche but fall prey to peregrine falcons, jaegers, and foxes.Reproductive BehaviourMating strategies, courtship displays, nesting or spawning behavior, and parental care. Multi-lang
Monogamous, often displaying high site-fidelity, returning to the exact same territory year after year. The nest is a simple, shallow scrape on open rocky ground or in short vegetation, lined carefully with leaves, moss, and grass. The female lays a consistent clutch of 4 olive-green, darkly mottled eggs. Both parents actively share incubation duties for 21 to 24 days. The precocial chicks are born fully downy and leave the nest within a few hours, foraging independently under parental protection. The female usually migrates south early, leaving the male to guide the chicks to fledging.Physical Measures
Length (cm)
21.0 - 26.0 cm
Weight (Grams)
84 g - 190 g
Offspring per cycleTypical number of young (live births, eggs, or seeds) produced by one adult in a single reproductive event or breeding season.3 - 4
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.
2 - 3 Years
Gestation / IncubationDuration from fertilization to birth (mammals) or to hatching (egg-laying species).
21 - 24
Lifespan EstimatedExpected duration of life from birth to natural death under wild conditions.
Males9 - 20 Years
Females9 - 20 Years
Sexual DimorphismPhysical differences in size, coloration, or morphology between males and females of this species.
Males Multi-lang
Distinct breeding color differences. Breeding males exhibit sharply defined, pure black-and-white facial masks with virtually no dark streaking on the crown, and the chestnut-rufous on the wings and scapulars is vibrantly bright and extensive.
Females Multi-lang
Breeding females share the overall harlequin pattern but are noticeably duller; the black facial markings are often blurred or mixed with greyish-brown streaks, the white areas are less pure, and the chestnut color is muted and interspersed with dark brown.
Evolutionary AdaptationsInherited traits and behaviors that improve the species' survival and reproduction in its specific environment. Multi-lang
Equipped with an exceptionally sturdy, wedge-shaped bill and hyper-developed neck muscles that allow it to lift, flip, or bulldoze objects like rocks, stones, and heavy kelp clumps that match or exceed its own body weight.
Features thick, textured scales on the lower legs and robust, blunt claws that provide highly secure traction, preventing slippage on wet, slime-covered coastal rocks and slippery intertidal reefs.
Main ThreatsDocumented pressures reducing the population: habitat loss, hunting, disease, climate change, and invasive species. Multi-lang
Threatened by widespread coastal development and pollution (such as oil spills) that severely damage intertidal food supplies. Climate change posing an existential threat to high-arctic breeding tundra due to shrub encroachment and melting permafrost.
Interesting FactsSurprising or notable facts that highlight what makes this species unique or ecologically important. Multi-lang
True to their name, these birds have been observed working in perfect, coordinated pairs or small groups to flip over large rocks or heavy debris that a single shorebird could not move alone.
They are exceptional long-distance marathon fliers; individuals tracked with geolocators have completed non-stop ocean flights of up to 7,600 kilometers over the Pacific during their annual migrations.