The setting sun cast an idyllic glow over the Kadra backwaters of the river Kali. “They will come,” said CR Naik, “I know”. His companions were my friends Sachin and Bhuvan who were visiting the Kali Tiger Reserve, in north Karnataka. They vividly recounted to me how they were unconvinced at first — after all one doesn’t see Malabar pied hornbills on a wish. Then it began. First there was one bird, followed by ten. The hornbill numbers swelled, filling the evening air with their raucous cacophony, feeding in a grove of poison nut (Strychnos nux-vomica) trees and then flying across to roost on a little island in the river. Sachin, Bhuvan and Naik counted 120 Malabar pied hornbills.
CR Naik works as a forester in the Karnataka Forest Department. He is passionate about all wildlife, and hornbills hold a special place in his heart. Naik has monitored nests of Malabar pied hornbills for many years and takes immense pride in “guarding” them until the chicks fledge. He understands their needs and habits and likes to introduce people to the lives of these birds.
Hornbills are fascinating and funky birds. There are 54 hornbill species found on Earth today. With their large beaks and characteristic headgear — a boxy chamber called a casque — each could be a winning entry in a costume party. The Malabar pied hornbill (Anthracoceros coronatus) is endemic to the Indian subcontinent and found as three disjunct populations in the Western Ghats, Central Indian forests, and Sri Lanka. There have also been some recent reports of it breeding in the Satpuras.
The Malabar pied hornbill has dapper black-and-white plumage: jet-black neck and neat white underparts make it seem like they are dressed for a tuxedo party. Their black wings have white tips that form a halo when in flight. White margins flank the long black tail. Malabar pied hornbills can be 65-90 cm long and weigh about a kilogram. They call in loud raucous cackles (that sound like kleng-keng or kak-kak) interspersed with squeals.
Most hornbills show what biologists call sexual dimorphism — the male and the female differ in size and looks. Dimorphism in the Malabar pied hornbill is not stark, but females tend to be slightly smaller than males. Their faces and casques differ a bit. Females have their eyes fringed by bare skin that looks white to pale bluish; the male lacks this pale skin patch. Both sexes have a white patch on the side of the neck. The large cream-yellow beak carries atop it an over-sized casque that earns this group of birds their moniker “hornbills”.
In the Malabar pied hornbill, the casque ends in a single point (compared with the great hornbill that has a squarish end). As with other large hornbills, the casque of the Malabar pied hornbill looks like an awkwardly placed clunky crown. I love watching these birds swivel their casqued heads when trying to get a good look at you, one eye at a time, beyond the big beak. The casque might look heavy, but it is hollow and made of keratin (same as human fingernails). It supposedly acts as a resonating chamber to amplify sounds when the birds call.
Malabar pied hornbills prefer moist but slightly open forests. They usually move around in small groups of up to 10 birds. Sometimes though, many tens of them gather at large fruiting trees or roosts, like the little island in the Kali backwaters. In some places like Dandeli Wildlife Sanctuary, flocks of 100 or more are regularly seen in areas with plenty of fruit trees. Although Malabar pied hornbills will usually stay up in the canopy, they occasionally come down to the ground for a dust-bath. It is surmised that this beauty regimen helps disinfect the spaces between the feathers and keeps parasites at bay.
Hornbills have fascinating breeding habitats. Like many other hornbills, the Malabar pied hornbill makes its nest in the natural cavities of old trees, about 4-15 m above ground, and favours large trees such as Tetrameles nudiflora and Terminalia bellerica. Both parents tend to the young. Sometime in March-April, the female seals herself into the nest cavity. She blocks the entrance with poop, mulch and pulp and for almost a month incubates a clutch of two to four eggs. The male, during this time, ferries food to its house arrested mate. The female comes out of the nest cavity when the oldest chick is about 3-4 weeks old and then helps the male feed the chicks. The chicks stay inside the cavity for a few more weeks until they become ready to fledge.
The fruit-dominated diet of the Malabar pied hornbill probably means that it plays a role in dispersing (or spreading) the seeds of many tree species. Studies from Northeast India and Southeast Asia indicate that hornbills farm the forest, maintaining the diversity of tree species that they feed upon. We may expect the Malabar pied hornbill to play a similar role where it is found, but we do not know as yet.
As with so many other creatures on Earth today, the Malabar pied hornbill has to contend with humans to survive. Some of its troubles are common to large-bodied animals everywhere. Space, for instance. These birds largely eat fruits, which tends to be a patchy resource in a forest. Trees bear fruit only during select parts of the year, which differs among species, and not all trees of a species will fruit. So, a group of Malabar pied hornbills need a large patch of forest that contains enough fruit trees to sustain them through the year. The breeding habits of the Malabar pied hornbill also has it depend on old trees, preferably large ones, with natural cavities. Old trees exist mostly in old-growth forests, being rare even there.
Agriculture, plantations, roads, mines, and other human land-use have not only reduced the forest available to these birds, but also fragmented remaining forests into smaller parcels that may be insufficient to support the needs of hornbills. Forest fragments often have large old trees dying out, making nest trees scarce. Fruit tree species favoured by hornbills can decline in disturbed, fragmented forests, creating a shortage of food resources. Logging operations can render even large forest patches unsuitable for hornbills. Hunting remains a threat to these birds. The Malabar pied hornbill has been ranked “near threatened” by the IUCN and experts think that Malabar pied hornbill numbers may be declining.
Hornbills, including the Malabar pied hornbill, are among the most charismatic and splendid birds, but much remains to be known about their ecology. Perhaps because these big birds can be elusive and relatively rare, they are hard to study. There are few programmes in India dedicated to a long-term understanding of hornbill ecology, but hopefully this will change soon with many young wildlife biologists devoting themselves to the study of these amazing birds. Meanwhile, unsung heroes like CR Naik will keep guard over hornbills and their habitats.