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It was a serendipitous visit to the Galápagos Islands that helped Charles Darwin solidify his theory of evolution — an idea he had long been developing through the study of fossils and natural history. What captivated him most during his voyage aboard the HMS Beagle in the 1830s were the beaks of the 14 species of finches he encountered on different islands. He observed distinct variations in beak size and shape among them, which he proposed were adaptations to different food sources shaped by island-specific ecological pressures. This, combined with his broad understanding of natural history — including botany, zoology, geology, and entomology — helped him craft what I believe is not just a theory but a fact: evolution. An equally brilliant naturalist, Alfred Russel Wallace, working in Southeast Asia, reached a similar conclusion. The rest, as they say, is history.
Ever since I saw the slender-billed scimitar-babbler (Pomatorhinus superciliaris) during a visit to Arunachal Pradesh in May 2025 with ace bird guide Abidur Rahman, I have been intrigued by its remarkably long, slender, downward-curved beak. It seems almost ill-suited for its habitat of dense, tropical and subtropical rainforests with thick undergrowth. The slender-billed scimitar-babbler is found from western Nepal to Arunachal Pradesh, from 1,300 m to 3,500 m (sometimes as low as 600 m) in thick forest, deep valleys and gorges, often in old bamboo growth. They are generally found in small flocks or in pairs during the breeding season.
Among the 15 scimitar-babbler species in the world, ten are found in India, and all have downcurved bills. A scimitar is a curved sword, which is what gives the group the name. The long-billed scimitar-babbler’s (Pomatorhinus ochraceiceps) stout, red bill is around 31-37 mm long but not as dramatically elongated as the slender-billed species, whose bill ranges between 43-57 mm, roughly a quarter of the bird’s body length. It reminds me of the hoopoe, another bird with a similarly long, curved bill used for probing the wet ground for insects and grubs. Does the slender-billed scimitar-babbler use its bill in the same way, probing moss-covered branches or damp forest floor for hidden prey? In the Handbook of the Birds of India and Pakistan, Salim Ali and S. Dillon Ripley describe its diet as beetles, ants, other insects and larvae, along with berries and nectar. They note: “Hunts on the ground progressing by long rat-like hops, or in undergrowth, commonly mounting up into leafless Salmalia and other flowering trees for nectar”.
To better understand the bird’s feeding adaptations, I consulted ornithologists and birders familiar with Northeast India. Wildlife biologist and photographer Kallol Mukherjee told me, “I’ve seen them on the ground only twice, both times near cattle-grazing areas. Interestingly, they were foraging alongside white-collared blackbirds.”
Cover photo: The slender-billed scimitar-babbler is easily recognised by its long, down-curved bill —shaped like a scimitar, the curved sword it’s named after. Photo: Kallol Mukherjee
Despite being such a remarkable bird, little is known about its ecology, behaviour, or the evolutionary reason behind its exaggerated bill. Does it feed on a specific flower with a curved corolla? This question arises from examples like the sword-billed hummingbird (Ensifera ensifera) of the Andean tropics in South America — the only bird species with a bill longer than its body (excluding the tail). It co-evolved with long-tubed flowers such as Passiflora mixta, relying on them for nectar while serving as their pollinator. Because of its highly specialised beak, it is among the few birds capable of accessing these flowers with long corollas.
Could a similar ecological relationship exist between the slender-billed scimitar-babbler and a curved-flower species in its Indian habitat? I posed this question to Dr Navendu Page, author of Trees of Arunachal Pradesh: A Field Guide. His response was insightful: “Judging by the foraging behaviour of this and other scimitar-babblers, I believe these birds are primarily insectivorous but opportunistically feed on nectar. Unlike hummingbirds, which face strong evolutionary pressures to adapt to specific flower structures, scimitar-babblers likely do not rely on nectar enough to drive such extreme bill adaptations. Still, a long bill may serve dual functions — effective insect foraging and occasional nectar feeding — without being a disadvantage.”
He continued: “Since the species mainly inhabits temperate forests above 1,500 metres, it may frequently feed on Rhododendron species, which are common in Arunachal Pradesh and serve as significant nectar sources. However, most rhododendron flowers are large, open, and tubular — forms not uniquely suited to the slender-billed’s bill. It’s also possible that the bird pierces flowers at the base to “rob” nectar without pollinating them — a strategy where its curved bill could be quite helpful. There are many potential floral candidates, but our knowledge of plant-bird interactions and even the region’s flora remains limited.”
His comments raised more questions than answers, but that is the essence of scientific inquiry. A comprehensive study of the slender-billed scimitar-babbler’s behaviour, ecology, and morphological adaptations would be both fascinating and valuable. I am reminded of a 1932 paper by Dr Salim Ali in the Journal of the Bombay Natural History Society, titled Flower-birds and Bird-flowers in India. Alongside his renowned Baya papers, this work laid the foundation for the study of avian natural history in India. In it, Ali documented bird visits to flowers — not just for nectar but also for the insects that flowers attract. He also indirectly hinted at the bill adaptations of different species, depending upon the flower species that they feed upon.
Wouldn’t it be rewarding if a bright student, with sound knowledge of both botany and ornithology, undertook a study on the ornithophily (bird-flower interactions) of scimitar-babblers and the functional relevance of their bill shape? Perhaps I am reading too much into the bird’s slender, curved, pointed bill, but curiosity is the first step toward discovery. At the very least, I urge you to read Salim Ali’s paper. It may whet your appetite for inquiry.
Like most birds of the forests, the slender-billed scimitar-babbler faces many problems, most noteworthy among them habitat destruction. Large-scale cutting of forests is thankfully banned in India, but traditional jhum cultivation (cutting and burning tracts for cultivation) is still practised; we saw this all along our travels in Arunachal Pradesh. Hunting of birds is also still an issue, with the government and NGOs trying to stop it. In many areas, local communities have come forward to stop hunting and have developed community reserves, which need scaling up.
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