The beautiful red, decurved bill of the Abyssinian Scimitarbill helps it seize insects hiding in the fissures of tree trunks and limbs in East Africa.
By Rex Graham
They also probe the openings of ant galls, which are hollow structures a few centimeters in diameter on Acadia trees that house a variety of invertebrates.
Birdwatchers are inexplicably drawn to strongly decurved bills, probably because of their artful symmetry. Other than parrots and birds of prey, few other birds have taken this curved evolutionary path.
Why? A straight bill is a generalist tool, but a curved one is specialized. With one, a bird enters an ecological niche where hard-to-find food becomes findable. A curved bill seems to permit “a foraging method involving gentle probing along precise, but complex routes,” British scientists wrote in the journal Bird Study.
Curving ‘search arc’
In Long-billed Curlews, the scientists said the curvature favors a “greater search arc for detection of prey beneath the surface of mudflats in winter, or easier capture of insects amongst long vegetation on the breeding grounds.”
With its curved bill, the Abyssinian Scimitarbill is an arboreal version of a woodpecker and a Long-billed Curlew. It finds insects hiding in the complex crevices of tree trunks. Instead of using brute force to chip away bark like a woodpecker, Scimitarbills probe under it, like a curlew probing for crabs hiding under rocks.
Other curved-bill birds
- Red-billed Scythebill
- Mountain Velvetbreast
- Northern Bald Ibis
- Southern Ground-hornbill
- Scimitar-billed Woodcreeper
- Black-billed Sicklebill
- Sickle-billed Vanga
This bird is an outlier in the woodcreeper subfamily. The Red-billed Scythebill uses its curved, sharply tipped saber to pick insects and other invertebrates from crevices in trees from Panama to southern Brazil. It probes holes in bamboo and fallen logs, clumps of moss and bromeliads. “Most prey taken from holes in bamboo poles made by, among others, various woodpeckers, Amazon bamboo rat or Peruvian Recurvebill,” says the Handbook of the Birds of the World.