By Aparajita Datta
Last week, we saw how hornbills are important for seed dispersion in forests. Their nesting habits are linked to how they disperse seeds. So here’s some more information on how these interesting birds nest. Hornbills make their nests in tree hollows. They look for hollows that are large enough for the mother hornbill and her chicks to stay inside in till they are big enough to fly. They cannot make a hole themselves, so they choose a tree-hole that is made by woodpeckers, or a natural hole that is formed where a branch breaks off.
While being locked up in the nest, the mother hornbill does not need to fly. So she sometimes sheds her wings and tail feathers, and re-grows a new set before it is time to leave the nest again. Sometimes, the mother hornbill only sheds her tail feathers, so that she is able to fly, if anything happens to the father hornbill.
When the mother hornbill is ready to lay her eggs, she goes into the hollow, after a lot of coaxing from the male. Then she locks herself inside by sealing the opening with her droppings. She only leaves a slit through which her mate can feed her.
The mother hornbill usually lays two eggs, although in the case of most of the large hornbills, only one chick survives. When the chicks hatch, it is possible to hear them calling from inside.
The father hornbill has to work very hard. If he does not supply enough food to his family, then the mother breaks out of the nest. However, on her own, she is not able to take care of her chicks, which often die if something happens to the father.
The father hornbill can carry lots of fruit in his throat pouch. Once, when I was watching a Wreathed Hornbill nest in Pakke Tiger Reserve, I saw the father bringing out 200 small fig fruits and pass them on inside. Sometimes, he may bring just a crab or a lizard. The father makes visits throughout the day, once every 1-2 hours. It can get stuffy inside the dark home, so the mother hornbill sits facing the slit with her mouth open, perspiring – the tips of the beaks are visible with a pair of binoculars.
In Arunachal Pradesh, hornbills start nesting in March and the mother and chick come out in July. She is cooped inside for almost 3 – 4 months. She does not like to dirty her nest with droppings, so she aims and shoots the droppings out of the slit Through the slit, she also spits out the seeds of the fruits she eats. Many hundreds of seeds fall on the ground below and become a huge pile. You will find a garden of seedlings below the nest tree, thanks to the hornbill. However, of the thousands of seeds that the hornbills throw out, only some grow into seedlings and even fewer into trees.
When the chicks are big enough, the mother hornbill breaks the seal and comes out first. The chick usually comes out a few days later. In some species, like the Great Hornbill, the mother hornbill comes out much earlier and helps the male feed the chick.
I have watched many nests over the years and it is always a joy to see the young bird come out of its safe home, perching hesitantly and looking out to see its big forest home for the first time.
[This article was first published in the Hindu In School.]