Sungrebe or American Finfoot
The Sungrebe is a unique, duck-like waterbird found in freshwater streams, rivers, and ponds from southern Mexico to Argentina, notable for its striped head pattern, lobed feet adapted for swimming, and remarkably secretive behavior as it swims low in the water along vegetated shorelines, with males possessing specialized pouches to carry their chicks.
Heliornis fulica
Scientific Name
Heliornithidae (Finfoots)
Family
Gruiformes
Order
H. f. fulica
Subspecies. From southern Mexico through Central and South America, including Costa Rica.
Range and Habitat of Sungrebe or American Finfoot
Geographic Range
The Sungrebe ranges from southern Mexico (Veracruz, Oaxaca) through Central America including Guatemala, Belize, Honduras, Nicaragua, Costa Rica, Panama, and throughout tropical South America to Paraguay and northeastern Argentina.
Migratory Patterns
The Sungrebe is non-migratory but may show local movements in response to water levels. During dry season, birds may concentrate in permanent water bodies. Some dispersal occurs during wet season when temporary wetlands fill.
Preferred Habitat
The Sungrebe requires specific aquatic habitats including slow-moving rivers and streams with overhanging vegetation, oxbow lakes and lagoons with vegetated margins, forested swamps and flooded forests, mangrove channels with dense canopy cover, and quiet backwaters with abundant aquatic vegetation. The species strictly avoids open water without cover and fast-flowing rivers.
Altitude Range
This is strictly a lowland species. In Costa Rica, it occurs from sea level to 600 m elevation, rarely up to 800 m, with most records below 300 m.
Costa Rica Habitat
In Costa Rica, the species occurs in suitable habitat on both slopes but is nowhere common. Key locations include Tortuguero National Park canals and lagoons, Caño Negro Wildlife Refuge, Río Frío region, Sarapiquí River and tributaries, Río San Carlos drainage, Térraba-Sierpe wetlands, scattered locations in Guanacaste wetlands, and various slow-moving rivers and oxbow lakes throughout the lowlands.
Conservation Status
Least Concern
Conservation Status
Population Status
Costa Rican populations are small and fragmented, likely totaling fewer than 1,000 individuals. Population density is low even in optimal habitat, typically less than 1 bird per kilometer of waterway.
Major threats include deforestation along waterways removing essential overhead cover, water pollution from agricultural runoff and pesticides, dam construction altering water flow patterns, motorboat traffic causing disturbance and wake damage, hunting despite legal protection, and mangrove destruction reducing coastal habitat.
Conservation efforts
The Sungrebe is protected under Costa Rican wildlife laws though enforcement is limited. Key wetland areas like Tortuguero and Caño Negro provide protected habitat.
Primary Threats
Major threats include deforestation along waterways removing essential overhead cover, water pollution from agricultural runoff and pesticides, dam construction altering water flow patterns, motorboat traffic causing disturbance and wake damage, hunting despite legal protection, and mangrove destruction reducing coastal habitat.
Sungrebe or American Finfoot Identification
How to Identify the Species
Rarity Level:
RareBest Viewing Times:
Early Morning (Dawn - 8 AM), Afternoon (2 PM - 5 PM)
Size
The Sungrebe measures 26-30 cm in total length, with a notably elongated, slender profile. Males weigh 120-140 g while females weigh 110-130 g. The wingspan ranges from 38-42 cm.
Plumage
Adults display striking plumage patterns with olive-brown upperparts featuring fine darker vermiculations. The crown and hindneck are black with a distinctive white stripe running from behind the eye down the neck sides. The wings show white patches visible in flight.
Distinctive Features
The species has a straight, pointed bill measuring 28-32 mm, colored olive to yellowish with a darker culmen. The legs and feet are distinctively banded yellow and black, with broadly lobed toes adapted for swimming.
Sexual Dimorphism
Males show more extensive black on the crown and more distinct white neck stripes. During breeding season, males develop brighter yellow on the bill and feet. Females are slightly smaller with browner overall coloration.
Diet and Feeding Behavior
Primary Diet
- The Sungrebe feeds on diverse aquatic prey including aquatic insects such as water beetles, dragonfly larvae, and water bugs. It also consumes small fish up to 8 cm in length, crustaceans including freshwater shrimp and small crabs, amphibians such as tadpoles and small frogs, mollusks including aquatic snails, and spiders found on water surface or overhanging vegetation.
Foraging Techniques
- This species employs various specialized foraging methods. It swims along vegetated margins, picking prey from the water surface and dives from the surface, propelling itself underwater with lobed feet.
Feeding Times
- The Sungrebe is most active during early morning from 5:30-8:00 and late afternoon from 16:00-18:00. It remains active during overcast days but becomes secretive during bright midday hours. Some feeding activity occurs nocturnally during full moon periods.
Behavior Patterns
Sungrebe or American Finfoot
Social Structure
Sungrebes are typically solitary except during breeding season when pairs form. They maintain individual feeding territories along waterways. Family groups may remain together for several weeks after breeding.
Song and Vocalization
The Sungrebe has a limited vocal repertoire. The primary call is a soft, descending “kew-kew-kew” or “whinny” lasting 2-3 seconds. It produces a single sharp “kek” or “pip” as an alarm call and soft purring or trilling sounds during courtship.
Courtship and Mating Ritual
Courtship involves synchronized swimming displays by pairs. Males perform head-bobbing displays while swimming in circles around females. Mutual preening occurs, particularly around the head and neck. Pairs engage in ritualized diving displays. Males present aquatic prey to females as courtship feeding.
Territoriality
Individuals defend linear territories along waterways, typically 200-500 meters of suitable habitat.
Birdwatching Tips
Best Locations for Spotting Sungrebe or American Finfoot
Prime locations include
- Tortuguero National Park canals (especially quieter side channels)
- Caño Negro Wildlife Refuge during wet season
- Río Frío boat trips
- Sarapiquí River quieter sections
- Las Baulas Marine Park estuary
- Palo Verde National Park wetlands
- Boat trips in Térraba-Sierpe mangroves
Best Time of the Year
Can be observed year-round, but slightly easier to detect during breeding season (May-August) when more vocal. Early wet season offers optimal water levels.
Common Behavior
This is one of Costa Rica’s most challenging water birds to observe. Look for a low-swimming bird with only head and neck visible. Check overhanging vegetation along quiet waterways.
Recommended Gear
Essential equipment includes 10×42 binoculars for distant viewing along waterways, a spotting scope useful for scanning from shore, a kayak or arrangement for quiet boat access, and a camera with long telephoto lens as birds rarely allow close approach.
Breeding and Nesting Behavior
Breeding Season
Breeding appears to occur year-round in Costa Rica with peaks during the early wet season from May to August when water levels are optimal and prey is abundant.
Nesting Sites
The nest is a flimsy platform of twigs and aquatic vegetation measuring 15-20 cm across. It is placed 0.5-3 meters above water on branches overhanging water, often concealed by overhanging foliage. Construction is minimal, sometimes just a few twigs on a horizontal branch. Both sexes participate in nest building over 2-3 days.
Clutch Size
Females lay 2-4 eggs, typically 3. Eggs are cream-colored to pale buff with reddish-brown spots.
Incubation Period
Incubation lasts approximately 10-11 days, remarkably short for the bird's size.
Parental Care
Both parents share incubation duties. Males uniquely carry young chicks in special pouches under their wings while swimming, a rare behavior among birds. Chicks can swim immediately after hatching but are carried by the male for the first week. Both parents feed young for 3-4 weeks until independence.
Did You Know?
Interesting Behaviors
The male’s ability to carry young in “wing pockets” is unique among American birds. Chicks can remain hidden under the male’s wings even while he swims and dives.
When threatened, Sungrebes sometimes pretend to be injured to distract predators from nests.Cultural Significance
The name “Pato Cantil” refers to the bird’s snake-like swimming appearance. Indigenous peoples along the Caribbean coast considered the bird a sign of good fishing. The species’ secretive nature has made it a symbol of mystery in local folklore.
Surprising Traits
The Sungrebe’s feet are not fully webbed but have broad lobes like coots, yet they are excellent swimmers and divers. The species can run across water surface for short distances when taking flight.
How do I identify this bird?
Look for a slender, low-swimming water bird with a long neck, pointed bill, and distinctive black and white striped head pattern. The bird sits very low in water with body mostly submerged. The lobed yellow and black feet are diagnostic when visible. No other Costa Rican water bird has this combination of features.
Where is the best place to see it in Costa Rica?
Tortuguero National Park canals offer the best chances, particularly quiet side channels with overhanging vegetation. Caño Negro Wildlife Refuge during wet season is also productive. Any slow-moving waterway with dense overhead cover in the lowlands could host this species. Patience and quiet observation are essential.
Is it endangered?
Listed as Least Concern globally, but populations are declining and fragmented in Costa Rica. The species’ specific habitat requirements make it vulnerable to waterway modifications. It’s one of the more challenging Costa Rican birds to find despite its wide distribution.