The mass movement of Malabar pied hornbills from Pillappara area in Athirappilly has raised concern among environmentalists.
They doubt large-scale felling of trees in the nearby plantation areas might have prompted the birds, which are sensitive to disturbances, to move from the area.
K.H. Amitha Bachan, founder, Western Ghats Hornbill Foundation, an organisation involved in conservation of hornbills, however, says it can be natural behaviour.
“It can only be a mass movement not a mass migration. It is natural in this season. Hornbills usually show such a behavioural pattern mostly twice a year. During May-June, after chicks are born, they will be found near the nesting area. Later, in July-August, they move in flock from one valley to another. For example, from Athirappilly to Edamalayar or Sholayar and from Sholayar to Parambikulam or Nelliampathy. The group will have males, females and chicks. It cannot be seen as migration. It is part of their socialisation process. It is during this time they select the pair for the next season,” Dr. Bachan says.
“In December too, during nesting season, males move to areas where there are plenty of fruits available. In that case they will return after some time,” he says.
Malabar pied hornbill ( Anthracoceros coronatus) is endemic to low-elevation riparian forests. Aided by conservation measures, its population has increased in the Athirappilly-Vazhachal forest area, says Dr. Bachan.
All the four south Indian species of hornbills — Great hornbill (State bird), Malabar pied hornbill, Malabar grey hornbill, and Indian grey hornbill — are found in the riparian forest of Athirappilly-Vazhachal area.
However, it has been reported that huge trees in the plantation areas under the Athirappily, Vazhachal and Charpa forest areas have been cut in the past two years.
According to local people, hundreds of huge trees such as aanjili (wild jack), chadachi (dhaman), erul, and mani maruthu in more than 20 ha in Athirappilly were felled recently. Activists fear human presence and the sound of huge machinery might have disturbed the birds.
As hornbills are sensitive, such disturbances can also be attributed to their movement, says Mr. Bachan. There were proposals to retain the miscellaneous growth of huge trees in the teak plantations for not disturbing the natural habitat of hornbills. In some areas, such trees have been retained, he says.
The main threat to hornbills apart from poaching is the lack of suitable nesting locations. Natural hollows of tall canopy trees serve as their nests. Forests undisturbed by human presence are vital for the survival of these birds.
