AnimaliaIUCN LCIn Progress Recent Sighting
Crotophaga sulcirostris
Groove-billed Ani
Swainson, 1827
Detailed Texts Multi-lang
The Groove-billed Ani (Crotophaga sulcirostris) is a medium-sized bird related to cuckoos, with an unmistakably lanky and unkempt appearance. Its entire plumage is a dull black that, under direct sunlight, can show faint purple or greenish iridescent flashes. Its most extreme anatomical feature is its bill: it is massive, very high, laterally compressed, and features distinctive longitudinal grooves or striations carved into the upper mandible. It possesses a disproportionately long, drooping tail that seems loosely attached to its body, and short, rounded wings. Its perching posture is often hunched, giving it a languid or clumsy appearance.
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Taxonomy
PhylumChordata
ClassAves
OrderCuculiformes
FamilyCuculidae
GenusCrotophaga
Taxonomic AuthoritySwainson, 1827
Ecology & Status
Origin
Native
Population Trend
Stable
Breeding Season
Wet Season
Trophic Role
Insectivore
Recent Sightings
Yes
Habitat Summary Multi-lang
It is a bird of open spaces that has benefited greatly from deforestation and agriculture. It avoids dense forests and prefers savannas, cattle pastures, agricultural fields, thorny scrublands, roadsides, and suburban areas. It requires some isolated shrubs or trees for nesting and roosting. In Costa Rica, it is a highly common and noisy bird in the dry lowlands of Guanacaste and the Central Valley, tolerating very warm climates.Behaviour Multi-lang
Highly gregarious, diurnal birds, living in cohesive flocks of 5 to 15 individuals. Their flight appears inefficient, alternating rapid wingbeats with unsteady glides where their long tail seems to unbalance them. They spend the day walking on the ground in search of insects and communicate constantly with harsh, whining whistles that sound like a drawn-out 'teee-hooo!'. At dusk, the entire flock huddles tightly together in dense branches to sleep.Social Activity Multi-lang
Extremely social year-round. They maintain close-knit family groups that forage, roost, allopreen, and nest together. The group cooperatively defends its territory against other flocks of anis.Feeding Guild Multi-lang
Insectivore / Ground and commensal forager.Trophic Chain Details Multi-lang
Opportunistic omnivore with a strong insectivorous preference. Its diet is based on grasshoppers, beetles, bugs, and spiders, but they also catch small lizards and eat berries or seeds if insects are scarce. Adults can be prey for falcons and savanna hawks. Their communal nests are frequently attacked by snakes, white-faced capuchins, and opossums.Reproductive Behaviour Multi-lang
They have a cooperative breeding reproductive system. A flock (1 to 4 monogamous pairs) builds a single, bulky open-cup nest of thorny sticks and twigs, lined with green leaves, in the fork of a tree. Multiple females lay their white eggs in this same nest, resulting in clutches that can exceed 15 eggs. All group members (males, females, and young from previous broods) take turns incubating the eggs for 13-15 days and cooperate intensely to feed and defend the altricial chicks. The chicks leave the nest very quickly, in just 10 days, climbing through the surrounding branches.Physical Measures
Length (cm)
30.0 - 34.0 cm
Weight (Grams)
70 g - 90 g
Offspring per cycle3 - 15
Sexual DimorphismNo
Lifespan
Sexual Maturity
12 - 24 Months
Gestation / Incubation
13 - 15
Lifespan Estimated
Males4 - 8 Years
Females4 - 8 Years
Evolutionary Adaptations Multi-lang
Megafauna Following (Commensal Foraging): Instead of actively searching for insects in the grass, anis have evolved to closely follow large herbivores (cows, horses). They walk alongside them or perch on their backs to swiftly catch grasshoppers and insects flushed out by the livestock as they walk.
Thermoregulatory Posture (Sunbathing): Their feathers easily absorb moisture, so early in the morning they adopt a peculiar posture: they perch on exposed branches with their backs to the sun and spread their wings completely. This helps them dry off the dew and raise their body temperature after the night.
Main Threats Multi-lang
Pesticides and Agrochemicals: By foraging intensively in cattle pastures and agricultural fields, they are highly susceptible to secondary poisoning from consuming insects sprayed with chemical pesticides.
Road Kills: Their flight is notoriously weak, low, and erratic. They often cross roads flying just inches above the asphalt or chase insects in the ditches, resulting in frequent fatal collisions with vehicles.
Interesting Facts Multi-lang
The Tick-eater Myth: Despite their common Spanish name (Garrapatero / Tick-eater) and frequently being seen perched on cows, they rarely eat ticks. Their main interest in livestock is not their parasites, but rather using the giant animal as a 'beater' to flush out grasshoppers in the grass.
The Egg Wars: Their communal nesting system is brutal. Multiple females lay their eggs in the same giant nest. However, before incubation begins, the dominant females (usually the last to lay) toss the eggs laid by subordinate females out of the nest to ensure the success of their own offspring.