Groove-billed Ani
The Groove-billed Ani is a distinctive, all-black bird found in open and semi-open habitats from southern Texas through Central America to northern South America, characterized by its large, curved bill with conspicuous grooves, long tail, and unusual communal breeding behavior where multiple pairs cooperate to build a single nest and raise their young together.
Crotophaga sulcirostris
Scientific Name
Cuculidae (Cuckoos)
Family
Cuculiformes
Order
Range and Habitat of Groove-billed Ani
Geographic Range
The Groove-billed Ani ranges from southern Texas through Mexico, Central America including all countries to Panama, and into northern South America including Colombia, Venezuela, Guyana, Suriname, Ecuador, and northwestern Peru.
Migratory Patterns
The species is largely sedentary in Costa Rica with no true migration. Some local movements occur following food availability and breeding opportunities. Northern populations in the United States and northern Mexico are partially migratory.
Preferred Habitat
The Groove-billed Ani inhabits open and semi-open areas including pastures with scattered trees and bushes, agricultural lands and crop fields, forest edges and clearings, gardens and urban parks, roadsides with scrubby vegetation, and wetland edges with appropriate perches. It strongly avoids dense forest interior and requires open areas for foraging.
Altitude Range
In Costa Rica, the species occurs from sea level to 2,400 m elevation, though most common below 1,500 m. Occasionally recorded up to 2,600 m in appropriate habitat.
Costa Rica Habitat
In Costa Rica, the species is widespread in appropriate habitat throughout both slopes. It occurs from the lowlands to middle elevations in all provinces but is most common in agricultural areas. Absent only from dense forest and highest elevations. Particularly abundant in Guanacaste Province, the Central Valley, Caribbean lowlands, and Pacific coastal areas. Common around San José suburbs and agricultural zones.
Conservation Status
Least Concern
Conservation Status
Population Status
Costa Rican populations have likely increased with deforestation creating more suitable habitat. Density can reach 20-30 individuals per km² in optimal agricultural areas.
The species faces few significant threats due to its adaptability.
Conservation efforts
The Groove-billed Ani requires no specific conservation measures. It is protected under general wildlife laws in Costa Rica.
Primary Threats
The species faces few significant threats due to its adaptability.
Groove-billed Ani Identification
How to Identify the Species
Rarity Level:
CommonBest Viewing Times:
Early Morning (Dawn - 8 AM), Afternoon (2 PM - 5 PM)
Size
30-35 cm in total length. Males weigh 70-90 g while females weigh 65-85 g.
Plumage
Adults are entirely glossy black with an iridescent sheen showing bronze, purple, and green tones in good light. The feathers have a loose, shaggy texture giving the bird a somewhat disheveled appearance. The wings show minimal iridescence compared to the body. The long, graduated tail appears loosely constructed and is often held at odd angles.
Distinctive Features
The most distinctive feature is the laterally compressed bill measuring 25-30 mm, which is remarkably high and narrow with prominent grooves along the upper mandible (usually 3-4 grooves, visible only at close range). The bill lacks the smooth, high arch of the Smooth-billed Ani. The bird has a distinctive hunched posture and weak-looking, floppy flight.
Sexual Dimorphism
Sexual dimorphism is minimal. Males average slightly larger than females, but there are no reliable plumage differences. Bill size may be marginally larger in males.
Diet and Feeding Behavior
Primary Diet
- The Groove-billed Ani feeds primarily on large insects including grasshoppers, crickets, caterpillars, beetles, and cicadas. It also consumes ticks and other parasites picked from cattle, spiders, small lizards and frogs, snails, seeds and fruits (particularly during dry season), and occasionally eggs and nestlings of small birds.
Foraging Techniques
- This ani typically forages on the ground in small flocks, walking and running through grass. It follows cattle and other large mammals to catch disturbed insects and remove ticks.
Feeding Times
- Active throughout the day with peaks in early morning (6:00-9:00) and late afternoon (15:00-18:00). Groups often forage during the hot midday when insects are active.
Behavior Patterns
Groove-billed Ani
Social Structure
These are highly social birds, living in groups of 4-12 individuals, occasionally up to 20. Groups consist of multiple breeding pairs plus helpers. All members participate in territory defense, nesting, and chick rearing. Complex social hierarchies exist within groups. Young birds may remain with groups for extended periods. Temporary feeding aggregations form at productive sites.
Song and Vocalization
The primary call is a liquid, ascending “TEE-ho” or “kwee-u” with the first note higher. Groups produce constant soft chattering and clicking sounds while foraging. Alarm calls include harsh “kek-kek-kek” notes. Bill clicking is used in close-range communication.
Courtship and Mating Ritual
Courtship involves mutual preening and allofeeding between pair members. Males present nest material and food to females. Groups perform communal displays with synchronized calling and posturing.
Territoriality
Groups defend territories of 2-10 hectares depending on habitat quality. All members participate in boundary patrols and defense.
Birdwatching Tips
Best Locations for Spotting Groove-billed Ani
Common viewing areas include pastures throughout Guanacaste Province, agricultural areas in the Central Valley, roadsides anywhere in appropriate habitat, La Ensenada Wildlife Refuge, edges of Palo Verde National Park, suburban parks in San José, Caribbean lowland farms, and rice fields in various regions. Almost any open area with scattered bushes may host groups.
Best Time of the Year
Observable year-round with highest activity during breeding season (May-September). Early morning and late afternoon offer best viewing of active groups.
Common Behavior
Look for black birds with floppy flight crossing roads or pastures. Watch for groups walking through short grass near cattle. Listen for liquid “TEE-ho” calls from bushes. Check fence lines and isolated trees where groups perch. Often allows close approach while foraging. Groups are conspicuous and noisy. The weak, labored flight is distinctive.
Recommended Gear
Basic equipment includes binoculars (8×42) for observing group behavior, a camera with moderate telephoto for group interactions, and a vehicle for roadside observation opportunities. This is generally an easy species to observe and photograph.
Breeding and Nesting Behavior
Breeding Season
Basic equipment includes binoculars (8x42) for observing group behavior, a camera with moderate telephoto for group interactions, and a vehicle for roadside observation opportunities. This is generally an easy species to observe and photograph.
Nesting Sites
The nest is a communal structure built and used by multiple pairs within the group. It consists of a bulky platform of twigs measuring 25-30 cm across and 15-20 cm deep. The nest is typically placed 2-8 meters high in trees or tall bushes, often in isolated trees in pastures.
Clutch Size
Each female lays 3-5 blue-green eggs, but communal nests may contain 10-20 eggs total from multiple females.
Incubation Period
13-14 days
Parental Care
This species shows complex cooperative breeding. All group members incubate eggs and feed nestlings. Eggs at the bottom of layered clutches may be buried and fail to hatch. Feeding visits occur every 10-20 minutes by various group members. Young fledge at 10-11 days but are weak fliers initially.
Did You Know?
Interesting Behaviors
Groups synchronize their activities, often sunbathing together with wings spread. Groups have been observed “anting” – rubbing ants on their feathers for parasite control.
Cultural Significance
The name “garrapatero” refers to their tick-eating habits appreciated by farmers. Various indigenous names mimic their calls. The communal lifestyle has made them subjects of behavioral studies. Their presence is often seen as beneficial in agricultural areas.
Surprising Traits
Individual birds can recognize all group members and maintain specific relationships. Groups make collective decisions about foraging locations and nest sites.
How do I identify this bird?
Look for an all-black bird with shaggy plumage, long tail, and distinctive high, narrow bill. The grooves on the bill are visible only at close range. The weak, floppy flight and liquid “TEE-ho” call are diagnostic. Usually seen in small groups walking through pastures.
Where is the best place to see it in Costa Rica?
Almost any agricultural area or pasture, particularly in Guanacaste Province and the Central Valley. They’re common along roadsides and often seen near cattle. La Ensenada Wildlife Refuge and edges of Palo Verde National Park offer reliable viewing.
Is it endangered?
No, the Groove-billed Ani is listed as Least Concern with stable or increasing populations. It has actually benefited from deforestation and agriculture, becoming more common in human-modified landscapes. No conservation concerns exist for this adaptable species.