In recent times, the natural homes of birds have been depleted due to environmental changes, as natural forests are replaced by plantations and other such modified terrain. In this context, the birds’ adaption to their severely-affected habitats is important. A bird that has adapted somewhat to such changes is the great Indian hornbill (Buceros bicornis).
According to a report in February 2019, a research conducted by the National Centre for Biological Sciences in Bangalore-Tata Institute of Fundamental Research (NCBS-TIFR) has come up with significant findings on the adaptability of birds.
The study, published in the journal Ornithological Science, found that the birds could adapt to new habitats provided their basic necessities were fulfilled. Further, despite different habitats, the birds followed similar nesting behaviour and adapted to the new environment.
The team chose to study the great Indian hornbills nesting in the Anamalai hills. For comparison, they located the study in the modified habitat in the Valparai plateau and the contiguous forests in the Anamalai Tiger Reserve and the Vazhachal Reserve forests. The modified habitat included tea, coffee and cardamom plantations and tribal settlements.
Taking the help of the local tribal people, the study team started monitoring nests of the great Indian hornbills from the beginning of breeding season in December. They observed eight hornbill nests, three located in contiguous forests and five located in modified habitats such as coffee plantations. After the females had entered the nests, they conducted direct nest observations on multiple nests using standard field protocols, taking care not to disturb the birds. All the observations were done manually.
Hornbills use the same nest over years. These birds were secondary-cavity nesters and chose cavities formed in large trees for nesting. They were monogamous, and the female, after copulation, sealed herself in the hole until the initial breeding period of two-four months is over. In this period, the female and the young ones were fed by the male bird, with fruit such as figs and animal matter. It was thus observed that hornbills were able to adapt to habitat modification provided their basic needs like food and nesting were fulfilled.
When the hornbills relocate to a new habitat, issues like hunting, modified land use, ensuing forest fragmentation, felling of large trees with the potential for nesting, the loss of fruit bearing trees could also affect hornbill nesting habits. Therefore, protection of these known nesting trees and retention of large trees that can be potential nests is absolutely essential.