Ibycter americanus (Boddaert, 1783)

Scientific Name and Common Name

Ibycter americanus (Boddaert, 1783), commonly called the red-throated caracara, shows size differences between sexes: males average 20.1 inches (51 cm) in total length, while females average 22.1 inches (56 cm).

Size Comparison to Related Species

Compared to the black caracara, this species is larger, and its plumage is mostly black, with white belly, tail feathers, and undertail feathers.

Plumage and Bare Skin

Both sexes have bare skin on the face and throat, with a small number of scattered black feathers on the throat; the exposed bare skin is red.

Male and female red-throated caracaras are otherwise similar in appearance.

Male Body Measurements

Detailed body measurements for males are: 35.55 cm wing length, 24.96 cm tail length, 2.5 cm bill length, and 5.41 cm tarsus length.

Female Body Measurements

For females, the measurements are: 35.93 cm wing length, 25.31 cm tail length, 2.58 cm bill length, and 5.62 cm tarsus length.

Geographic Range

This species lives in humid lowland forests across Brazil, Bolivia, Colombia, Costa Rica, El Salvador, Ecuador, French Guiana, Guatemala, Guyana, Honduras, Mexico, Nicaragua, Panama, Peru, and Venezuela.

Flight Characteristics

The red-throated caracara has slow flight, which is well suited for moving through the forest understory where vegetation is relatively sparse.

This sparse vegetation gives the bird better visibility to spot both food and predators.

Known Predators

Known predators of the red-throated caracara include the ornate hawk-eagle and the black-and-white hawk-eagle.

Foraging Habitat

Red-throated caracaras hunt in both the canopy and understory of lowland jungle, and forage mainly for insect nests.

Hunting Behavior Basics

Most hunt silently, but they will occasionally make soft caws, and sometimes hunt in groups.

Group Hunting Dynamics

When hunting in groups, one or two individuals scout for predators in the canopy, while the rest of the flock hunts in the understory.

Social Structure

This species is highly territorial, and social groups contain between four and eight individuals.

Diet Composition

Its diet is made up mostly of wasp and bee larvae, though it also eats mature insects, and forages for fruits and berries across the humid subtropical, tropical lowland, and mountainous parts of its range in Central and South America.

Critical Habitat Requirements

Forest biodiversity and old-growth forest are critical for this bird's specialized diet, because wasps and bees typically build their nests in hollows or on the branches of mature trees found in undisturbed old-growth forest.

Population Threats

Deforestation and intensive agricultural practices have severely harmed red-throated caracara populations, which likely explains why the species is rarely seen today.

Population Decline and Conservation Status

After the 1950s, the species' population and range declined rapidly in Costa Rica, Honduras, Panama, Ecuador, and French Guiana, leading to it being placed on the World Wildlife endangered list.

Historical Research Gap

Before 2013, very little was known about the red-throated caracara's feeding behavior.

2013 Feeding Behavior Study

That changed after a team of Canadian biologists from Simon Fraser University conducted months of research on the birds using camera surveillance at the Nouragues Field Station in French Guiana.

Nest Attack Strategy

The recorded scientific footage showed the birds use a rapid "fly-by" aerial diving attack strategy to knock wasp and bee nests down to the forest floor, while skillfully avoiding most stings.

Coordinated Group Hunting Tactics

The birds act with coordinated group precision, repeatedly diving then pulling upward, to drive off and confuse swarms of defending wasps around the hive.

Wasp Response to Predation

Researchers observed that neotropical defender wasps eventually abandon their damaged hives and retreat, alongside smaller worker wasps, to build a new nest at a different location.

Evolution of Predation Trait

Biologist Sean McCann observed that these intelligent birds have this highly specialized predation trait that evolved in response to wasps' typical behavior to cut losses and rebuild elsewhere.

Prey Population Impact Uncertainty

The impact of this predation on prey population numbers has not been determined.

Food Limitation Uncertainty

Additionally, it remains unclear how much the availability of the red-throated caracara's primary food source, wasp larvae, limits the species' ability to survive, since its complex predation strategy is closely linked to the behavior of neotropical wasps.

Sting Resistance Uncertainty

Whether the birds have any chemical resistance to wasp stings is also unknown.

Azteca Ant Chemical Trace

Chemical traces found on the birds' feet are similar to chemicals secreted by Azteca ants, which the birds likely encounter while moving along tree branches and visiting shared nest sites both species use.