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
Nycticorax nycticorax
Black-crowned Night-Heron
(Linnaeus, 1758)
Detailed Texts Multi-lang
A stocky, short-necked, medium-sized heron. Adults display a striking contrast between a jet-black crown and mantle (back) and pale grey wings, flanks, and tail. The underparts are a clean white to soft cream. They have an intensely red iris, a stout, pointed black bill, and short yellow-green legs that become pinkish during breeding. A defining feature during courtship is the presence of 2 to 3 long, narrow white plumes extending from the nape down to the back.
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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).Pelecaniformes
FamilyRank below Order. Groups closely related genera (e.g., Felidae = cats, Canidae = dogs).Ardeidae
GenusRank just above Species. The first word in the two-part binomial scientific name.Nycticorax
Taxonomic AuthorityThe scientist who first formally described and published this species, followed by the year of publication.(Linnaeus, 1758)
Record Completeness
95%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
Remarkably cosmopolitan, utilizing a vast range of freshwater, brackish, and saltwater environments. It heavily frequents riverbanks, freshwater swamps, interior marshes, lake margins, rice fields, and reservoirs, as well as coastal estuaries, lagoons, and mangrove borders. It requires dense shoreline vegetation, such as reeds, rushes, or low trees, to roost securely during daytime hours.BehaviourDaily activity patterns, movement, territory use, foraging style, and seasonal behavioral changes. Multi-lang
Primarily active from dusk until dawn, spending the daylight hours concealed in communal roosts within dense lakeside trees. They stand motionless at the water's edge, neck hunched tightly into the shoulders, waiting hours for prey to approach. They communicate with a harsh, barking call that sounds like a flat 'quok', often heard overhead at night.Social ActivitySocial structure: whether the species is solitary, paired, or colonial; hierarchy and communication. Multi-lang
Highly social and colonial when nesting and roosting, but strictly solitary when foraging. They form massive, noisy breeding colonies (heronries) that can consist of hundreds or thousands of pairs, frequently nesting alongside other heron and ibis species, leading to loud vocal squabbles over optimal twig material.Feeding GuildWhat the species eats, how it forages or hunts, and its role as a consumer in the food web. Multi-lang
Carnivore (piscivore/generalist wetland predator with a broad trophic spectrum focusing on aquatic vertebrates and larger invertebrates).Trophic Chain DetailsSpecific interactions in local food webs: prey species, predators, competitors, and scavengers. Multi-lang
Operates as a high-level opportunistic predator. Its generalist diet includes small fish, frogs, tadpoles, salamanders, aquatic insects, spiders, crayfish, snakes, small rodents, and even the eggs and nestlings of other waterbirds. Eggs and nestlings are heavily preyed upon by raccoons, crows, and raptors.Reproductive BehaviourMating strategies, courtship displays, nesting or spawning behavior, and parental care. Multi-lang
Monogamous for the season. The courtship display involves the male performing a 'stretch' dance, bowing forward while shaking his head and raising his white nape plumes. They build a platform nest of sticks and reeds in trees, bushes, or dense reedbeds. The female lays 3 to 5 pale greenish-blue eggs. Both sexes share incubation for 21 to 26 days. Regurgitated food is provided by both parents until chicks fledge at about 6 to 7 weeks.Physical Measures
Length (cm)
58.0 - 65.0 cm
Weight (Grams)
725 g - 1.01 kg
Offspring per cycleTypical number of young (live births, eggs, or seeds) produced by one adult in a single reproductive event or breeding season.3 - 5
Sexual DimorphismObservable physical differences between males and females of the same species (e.g., size, coloration, features).No
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 - 26
Lifespan EstimatedExpected duration of life from birth to natural death under wild conditions.
Males10 - 15 Years
Females10 - 15 Years
Evolutionary AdaptationsInherited traits and behaviors that improve the species' survival and reproduction in its specific environment. Multi-lang
Equipped with specialized night vision driven by a high density of rod cells within the retina, allowing effective spatial navigation and precise target tracking in near-total darkness.
Possesses a strong, straight, dagger-like bill that is highly versatile compared to other night-herons, capable of both piercing slippery fish and crushing heavy insects or small rodents.
Main ThreatsDocumented pressures reducing the population: habitat loss, hunting, disease, climate change, and invasive species. Multi-lang
Mainly threatened by the drainage and reclamation of wetlands for agricultural expansion, heavy bioaccumulation of environmental toxins (mercury and organochlorine pesticides) through its high trophic position, and systematic removal of nesting trees.
Interesting FactsSurprising or notable facts that highlight what makes this species unique or ecologically important. Multi-lang
It is one of the few bird species documented using tool-like lures to fish. Individuals have been observed deliberately dropping twigs, feathers, or insects onto the water's surface to attract curious fish within striking distance.
Young Black-crowned Night-Herons look fundamentally different from adults, covered in brown, heavily streaked and spotted plumage. When threatened in the nest, chicks defend themselves by aggressively vomiting their semi-digested stomach contents onto intruders.