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
Amazilia tzacatl
Rufous-tailed Hummingbird
(De la Llave, 1833)
Detailed Texts Multi-lang
The Rufous-tailed Hummingbird (Amazilia tzacatl) is a medium-sized, robustly built hummingbird famous for its bright coloration and dominant attitude. Its throat, chest, and back are covered in intense, dazzling emerald green feathers with a metallic sheen. Its diagnostic feature, instantly visible, is its tail and upper tail coverts of a vibrant rufous color (coppery chestnut or brick red). The belly is a pale grayish or light brown tone. It possesses a medium-length, straight, and markedly bicolored bill: the upper mandible is jet black, while the lower is a striking coral red or fleshy pink with a dark tip. Its legs are tiny and black.
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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).Apodiformes
FamilyRank below Order. Groups closely related genera (e.g., Felidae = cats, Canidae = dogs).Trochilidae
GenusRank just above Species. The first word in the two-part binomial scientific name.Amazilia
Taxonomic AuthorityThe scientist who first formally described and published this species, followed by the year of publication.(De la Llave, 1833)
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.
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.
Herbivore
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
It is a master of adaptability. It avoids closed, dark rainforests, thriving in open, sunlit areas altered by humans. It is exceedingly common at forest edges, clearings, scrublands, coffee plantations, pastures with scattered trees, and, most especially, in urban gardens, parks, and town squares. In Costa Rica, it is probably the most abundant hummingbird in the lowlands and mid-elevations of both slopes (Caribbean and Pacific), reaching up to 1,800 meters in the Central Valley.BehaviourDaily activity patterns, movement, territory use, foraging style, and seasonal behavioral changes. Multi-lang
They are diurnal birds with very conspicuous habits. They are constantly heard in gardens emitting a sharp, angry chirp, similar to two stones rubbing together quickly ('tzi-tzi-tzi!'), especially when chasing an intruder mid-flight. They sedentarily defend a nectar-rich flower patch, perching on the highest exposed branch of their territory like sentinels. In hovering flight, their agility is unparalleled; they can fly backward or remain suspended in the air thanks to their wings rotating in a figure '8'.Social ActivitySocial structure: whether the species is solitary, paired, or colonial; hierarchy and communication. Multi-lang
Highly antisocial and aggressively territorial, except in the brief moment of mating. They never travel in flocks. Males do not interact with females beyond copulation and will violently chase their own kind out of the garden.Feeding GuildWhat the species eats, how it forages or hunts, and its role as a consumer in the food web. Multi-lang
Nectarivore / Stationary territorial forager.Trophic Chain DetailsSpecific interactions in local food webs: prey species, predators, competitors, and scavengers. Multi-lang
Omnivore (Primarily Nectarivore and Insectivore). It depends heavily on the nectar of red and tubular flowers (such as Stachytarpheta, Heliconias, and Hamelia) for quick energy. However, to obtain necessary proteins to survive, it hunts small gnats in mid-air and steals small spiders from their webs. Despite their aggressiveness, they can be preyed upon by small arboreal snakes (vine snakes), cats, and occasionally, large spiders or praying mantises that ambush them on flowers.Reproductive BehaviourMating strategies, courtship displays, nesting or spawning behavior, and parental care. Multi-lang
The female assumes full responsibility for raising the young. She builds a tiny, very compact cup-shaped nest using soft plant fibers (like balsa or dandelion), tightly bound and shingled on the outside with lichens and dry leaves glued with spider webs (for camouflage). The nest is placed on low horizontal branches (1 to 4 m high). She invariably lays 2 tiny white eggs. Incubation lasts about 15-16 days. The chicks are completely altricial, and the mother feeds them by inserting her bill into their throats to regurgitate nectar and insect mash. The young fledge at 18-22 days.Physical Measures
Length (cm)
9.0 - 11.0 cm
Weight (Grams)
4.5 g - 5.5 g
Offspring per cycleTypical number of young (live births, eggs, or seeds) produced by one adult in a single reproductive event or breeding season.2 - 2
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.
10 - 12 Months
Gestation / IncubationDuration from fertilization to birth (mammals) or to hatching (egg-laying species).
15 - 16
Lifespan EstimatedExpected duration of life from birth to natural death under wild conditions.
Males3 - 5 Years
Females3 - 5 Years
Evolutionary AdaptationsInherited traits and behaviors that improve the species' survival and reproduction in its specific environment. Multi-lang
Aggressive Territorial Flight: Unlike hermits that travel large routes, this hummingbird claims a flower patch as exclusive property. Its pectoral musculature is hyper-developed to perform violent aerial maneuvers, ramming like a projectile into any intruder (other hummingbirds, large butterflies, and even hawks) that dares to drink from 'its' flowers.
Torpor Metabolism (Mini-Hibernation): Because its heart beats over 1,000 times a minute while flying, it consumes immense amounts of energy. To avoid starving during cold early mornings or prolonged rains, it enters a state of 'torpor', drastically lowering its body temperature and heart rate to conserve calories until the sun comes out again.
Main ThreatsDocumented pressures reducing the population: habitat loss, hunting, disease, climate change, and invasive species. Multi-lang
Window Collisions: In their urban environment, while chasing other hummingbirds or flower reflections at extreme speeds, they often die upon hitting glass windows that reflect the garden at high speed.
Domestic Predators (Cats): When visiting low flowers in residential gardens, they over-rely on their speed, becoming frequent prey for stalking domestic cats.
Interesting FactsSurprising or notable facts that highlight what makes this species unique or ecologically important. Multi-lang
Elastic Nests: The nest is a true feat of engineering. The female builds it by intertwining plant down (like balsa or cotton) tightly bound with stolen spider webs. These spider webs make the nest elastic, stretching gradually as the chicks grow to prevent them from falling out.
Relentless Warriors: They have a reputation for being extremely aggressive and bad-tempered. Rufous-tailed hummingbirds have been documented chasing and attacking not only birds of their size but also oropendolas, toucans, and even hawks that get too close to their floral territory.