Hornbills are spectacular birds with long beaks, brightly coloured skin around the eyes and flashy loose pouch at the neck that help carry fruits. They get their name from the horn like structure on the top of their beak—the casque. Their distribution is globally limited to Sub-Saharan Africa, Indian-Subcontinent, Philippines, Indonesia and the Solomon Islands. In India, they are found in the Western Ghats and the north-eastern states.
Hornbills are distinctive in their food habits. They are one of the biggest frugivores (fruit eating birds) of the Asian rainforest as 40-70 per cent of their diet consists of large ficus fruits, figs, drupes and berries, usually red or black in colour. They are also picky eaters as they prefer juicy and sweet fruits of sizes larger than 10 mm in diameter. The availability of these fruit trees thus defines their behaviour, physiology and abundance in a given habitat. They also feed on small insects, lizards, frogs and snakes during their breeding season.
Owing to their diet, hornbills have a great ecological significance as they play a very important role in dispersal of seeds and subsequently regeneration of forests. Hornbills are considered an ‘umbrella’ or ‘keystone’ species as they are mainly found in undisturbed natural forests. As they swallow the fruits, the seeds are not ingested along with the flesh, but are regurgitated back while tiny fruit seeds are passed out with their droppings. They travel great distances in search of fruits leading to dispersal of seeds over wide areas, playing a critical role in maintaining the structure of a ecological community. They are thus known as the farmers of the forests (Naish, 2015); their presence signifying a healthy forest.
The hornbills are a slow breeding species with the female laying two eggs each breeding season, and usually one chick surviving. Small hornbills such as Brown hornbills can however fledge up to four chicks at a time. The female goes into nesting for two to three months when it is time to lay eggs while the male becomes the bread winner until the chick is hatched and grown. They use the hollows of trees for nesting, and the female seals up the nest with her droppings. This unique adaptation helps avoid predation. The breeding cycle of a hornbill ranges from 90-130 days depending on the species type (Hornbill Watch, undated).
Types of Hornbills
There are different types of hornbills depending on their physiology and appearance. India is home to nine species, of which four are found in the Western Ghats—Indian Grey Hornbill, Malabar Grey Hornbill, Malabar Pied Hornbill and the Great Hornbill (ncf-india.org). Narcondam Hornbill is found only in the Narcondam Island of Andaman Sea. Rufous-necked Hornbill, Great Hornbill, Wreathed-Hornbill, White-throated Hornbill and Oriental Pied Hornbill are distributed at higher density in north and the north-eastern parts of India (Ghosh, 2016). A. Rahmani, Senior Scientist Adviser at Bombay Natural History Society (BNHS) revealed to GnY that the Rufous necked Hornbill of north-east is listed as ‘vulnerable’ whereas Great Hornbill, White-throated Hornbill and Malabar pied Hornbill are considered as ‘near threatened’. The Narcondam Hornbill is listed under ‘endangered’ category. The rest are listed in the ‘least concerned’ category.
A citizen-science based initiative, Hornbill Watch which was launched by Nature Conservation Foundation (NCF) and Conservation India (CI) in 2014 records the number of sighting of different hornbill species across India. According to their recent update (from 3rd June 2014 to 28th Feb 2017) a total of 938 hornbills were recorded across India (hornbills.in).
Threats to Hornbills’ Existence
Naniwadekar, a Scientist at Nature Conservation Foundation (NCF), speaking with GnY, affirmed that hornbills face different threats across the country depending upon the culture, governance and densities of human population. Hunting and logging are probably the most relevant threats in the north-east India where law enforcement is poor and strong cultural practices are attached to hornbills. For example, the Great Hornbill and Rufous necked Hornbills are hunted for their spectacular feathers, casque and beaks to adorn the headdresses and their meat is believed to have medicinal value. He further stresses that another important threat to the hornbill is loss of habitat and fragmentation which is accelerating in the north-east regions. With traditional shifting cultivation practices being replaced by permanent cash crop plantations, particularly in community-owned lands leads to permanent loss in natural habitats and little scope for vegetation recovery. Also illegal occupation of land due to improper settlement of land rights or poor enforcement by the forest department, along with burgeoning human population pose significant threats to lowland forest habitats across the hornbill habitat.
As frugivores, the hornbills need a large forest with ficus trees. However, logging of these trees as well as tree species that provide nesting have led to significant reduction in their population.
A study conducted by Nature Conservation Foundation (NCF) at Namdapha Tiger Reserve and adjoining Miao Reserved Forest in Arunachal Pradesh found that the number of trees in hornbill habitat with less hunting and logging were twice as high as compared to the heavily disturbed site with more hunting and logging (Naniwadekar, et al., 2015). Similarly, T R Raman and D Muddapa in their study of fragmented rainforests of south Western Ghats also recorded that the abundance of Great Hornbills increased with fruit-bearing trees. Thus, they argue against rainforest fragmentation and recommend increased connectivity between patches, to help build back the hornbill population (Raman et al. 2003).
Rahmani went on to say that emphasis should be given on stopping hunting, poaching, and trapping of wildlife including hornbills. He opined that more conservational efforts should be directed towards the north-eastern states, where poaching is rampant. He remarked, “there is practically no hornbill left in Nagaland”, despite celebrating a festival in its name.
Naniwadekar too flagged better enforcement by the forest department—a body that needs strengthening, he feels, as they often do not have sufficient financial and logistic support. “Wildlife conservation measures have been focused mostly in state protected forests and reserved forests but the problem lies with the extended community managed un-classed forests where unchecked logging and hunting could freely take place”, he adds. Naniwadekar, adds, “Hornbills feed and breed in areas outside protected areas which are privately owned. Thus, only long term community engagement can potentially ensure that hunting pressures are low in these areas and that these private lands are modified in ecologically friendly way by ensuring wildlife persistence and economic benefits for the local community”. This can be done, he opines, through locally relevant and ecologically sensitive government policies towards agriculture and by developing platforms that allow systematic engagement between policy makers, local communities and wildlife conservationists. He further argues that this engagement is necessary even in cities, as larger hornbills like the Oriental Pied Hornbills have been reported from green spaces of cities like Kanpur, Chandigarh and Delhi.
The basic step thus would be to educate local communities on the ecological significance of hornbills to trigger a sense of willing participation in the conservation process. The Nyishi tribe of Western Arunachal Pradesh could be taken as an example for their recent significant contribution in the effort to save these majestic birds from extinction (Basu, 2016). The community has been closely working with Nature Conservation Foundation (NCF) in the surrounding areas of Pakke Wildlife Sanctuary and Tiger Reserve which is a crucial nesting habitat for hornbills. They adopt hornbill nests and help protect them under the Hornbill Nest Adoption Programme and also ensure conservation of hornbill habitats outside the protected area of the park (HNAP, 2011). Such initiatives should be encouraged keeping in mind that joint efforts among the Indian government, like-minded organisations, wildlife conservationists and local communities is the key to ensure safety for these unique hornbills species.
The population of hornbill species in India such as the Great Hornbill, Rufous-necked Hornbill and Narcondam Hornbill are on the verge of extinction due to human induced habitat loss and continued hunting. The whole change in attitude towards conservation of hornbill species pertaining to its significant contribution in sustenance of forests is very much required.