Eurylaimidae: The Vibrant Broadbills of Asia and Africa
The Eurylaimidae are a family of suboscine passerine birds—a group of perching birds with a simpler vocal organ than typical songbirds—found across a wide range from the eastern Himalayas to Indonesia and the Philippines. Known for their striking colors and unique silhouettes, these birds are specialized inhabitants of the tropical canopy.
While the family once included the sapayoa of the Neotropics, the asities of Madagascar, and the Calyptomenidae of Africa and Asia, modern taxonomic revisions have separated these groups into their own distinct families, leaving the Eurylaimidae as a more focused group of Old World suboscines.
Key Facts
- Distribution: Eastern Himalayas, Indonesia, and the Philippines.
- Physical Traits: Broad heads, large eyes, and flat, hooked beaks.
- Size: Typically range from 13 to 28 centimeters in length.
- Diet: Primarily insectivorous and carnivorous, though some species are frugivores.
- Nesting: Purse-shaped nests camouflaged with lichen and spider webs.
- Classification: Part of the infraorder Eurylaimides.
Physical Characteristics
Many species within the Eurylaimidae family are brightly colored, a trait that might seem counterintuitive for survival. However, they reside in the dense canopies of wet forests, where the dappled light and thick foliage allow them to remain hidden despite their vivid plumage.
Physically, they are characterized by broad heads, large eyes, and a distinctively flat, broad, and hooked beak. Juvenile birds generally resemble adults but possess duller colors, and in some species, they have shorter wings and tails.
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Behavior and Ecology
Diet and Hunting
Most broadbills are insectivorous and carnivorous. Their diet consists of insects, spiders, centipedes, and millipedes, as well as small vertebrates like lizards and tree frogs. They employ two primary hunting techniques: sallying from a perch to snatch prey mid-flight and gleaning prey directly from leaves and branches while flying.
While most prefer protein, some species incorporate fruit into their diet. Notably, the green broadbills of the genus Calyptomena and Grauer's broadbill are primarily frugivores (fruit-eaters), though they still consume some insects.
Social Life and Nesting
These birds are generally gregarious, often moving in flocks of approximately 20 individuals. Their nesting habits are particularly ingenious; they construct purse-shaped nests attached to suspended vines. To avoid predation, they leave a tail of fibers hanging below the nest and cover the exterior with spider webs and lichen, making the structure look like random forest debris.
Typically, a clutch consists of two to three eggs.
Taxonomy and Systematics
The family was first introduced in 1831 by French naturalist René Lesson. Anatomically, they are distinguished by a simple syrinx (the vocal organ of birds) with only one pair of muscles, 15 neck vertebrae, and front toes that are partially fused at the base.
Recent DNA sequence-based studies, including a 2019 study by Carl Oliveros and colleagues, have further clarified the phylogenetic relationships between Eurylaimidae and other families within the Eurylaimides infraorder.
Species Classification
The family currently comprises ten species distributed across seven genera. Some of these genera are monotypic, meaning they contain only one living species.
| Genus | Living Species |
|---|---|
| Cymbirhynchus | Black-and-red broadbill (C. macrorhynchos) |
| Psarisomus | Long-tailed broadbill (P. dalhousiae) |
| Serilophus | Silver-breasted broadbill (S. lunatus), Grey-lored broadbill (S. rubropygius) |
| Eurylaimus | Banded broadbill (E. javanicus), Black-and-yellow broadbill (E. ochromalus) |
| Sarcophanops | Wattled broadbill (S. steerii), Visayan broadbill (S. samarensis) |
| Corydon | Dusky broadbill (C. sumatranus) |
| Pseudocalyptomena | Grauer's broadbill (P. graueri) |
Frequently Asked Questions
What do broadbills eat?
Most are insectivorous and carnivorous, eating insects, spiders, centipedes, millipedes, lizards, and tree frogs. However, Grauer's broadbill and the green broadbills are primarily frugivores.
How do broadbills camouflage their nests?
They build purse-shaped nests and cover them with lichen and spider webs, while leaving a tail of fibers hanging below to make the nest look like random debris caught in the trees.
Where are Eurylaimidae birds found?
They are native to the regions stretching from the eastern Himalayas through to Indonesia and the Philippines.
What makes the Eurylaimidae physically distinct?
They are known for their broad heads, large eyes, and flat, hooked beaks, as well as a specific anatomical structure featuring 15 neck vertebrae and a simple syrinx.