AT A GLANCE
- Common Name: Oriental Dollarbird
- Scientific Name: Eurystomus orientalis
- Category: Birds
- Subcategory: Rollers
- Range: Eastern and southern Asia to Australasia, breeding from eastern Russia, China, and Japan south through India, Southeast Asia, to northern and eastern Australia
- Habitat Type: Open deciduous and evergreen woodlands, riverine forests, forest edges, clearings, mangrove swamps, and agricultural savanna with tall dead snag trees
- IUCN Red List Status: Least Concern
- Lifespan: 7 to 10 years
- Diet: Carnivorous/Insectivorous (flying insects including large beetles, cicadas, mantises, flying termites, moths, alongside small lizards)
- Average Size/Weight: Length 27 to 32 cm; wingspan 50 to 56 cm; weight 115 to 170 g
- Key Defining Feature: Stocky, dark greenish-blue roller with a heavy, broad crimson-orange bill and distinctive circular, coin-like pale silvery-blue patches on its wings that flash brightly in flight
Overview
The Oriental Dollarbird (Eurystomus orientalis), also known simply as the Dollarbird, is a charismatic, athletic aerial predator in the roller family Coraciidae. Widely distributed across the Asia-Pacific region, it earned its common name from early European naturalists who observed a striking pair of round, silver-dollar-sized translucent blue circles shining on the undersides of its wings when airborne. An extraordinary aerial acrobat, it spends hours perched motionless high on bare tree snags before launching into sweeping, tumbling loops to snatch large flying beetles mid-air.
Biology and Physical Characteristics
Eurystomus orientalis is a heavily built bird with a large head, short neck, and very wide, hooked bill brightly colored coral-red to fiery scarlet with a dark tip. Its plumage appears dark dusky brownish-black or charcoal-grey from a distance, but in bright sunlight it glimmers with rich iridescent tones of dark sea-green, turquoise, and purplish-blue, accented by a glowing cobalt-blue throat patch with delicate white streaks. The wings are long and broad, each bearing an unmistakable, round, pale translucent sky-blue patch on the outer flight feathers. Its short, sturdy legs are matching coral-orange.
Behavior and Ecology
Dollarbirds are quintessential sit-and-wait aerial hunters. They command prominent, exposed vantage points atop towering dead tree snags or telegraph poles. Upon spotting a flying insect up to 100 meters away, the bird launches into a breathtaking, powerful pursuit, executing rolling dives, loops, and somersaults to engulf the prey in its cavernous, wide-gaped beak. Highly vocal, particularly around dusk, they announce their territories with harsh, grating, cackling ‘kak-kak-kak’ calls. Breeding pairs nest in natural hollows of high dead trees, often aggressively evicting parrots and owls from prime tree cavities.
Conservation and Human Impact
The Oriental Dollarbird is evaluated as Least Concern by the IUCN Red List. It maintains an immense global breeding range and large, stable overall populations. However, migratory populations in temperate East Asia (such as Japan and South Korea) and Australia face localized pressures from the removal of mature dead trees and hollow-bearing forest snags essential for nesting.
Interesting Factoid
The Dollarbird gets its quirky name from the gleaming, perfectly circular silvery-blue patches on the underside of each wing, which look exactly like shining silver dollar coins when it flies overhead.