Kendrapara: The number of seasonal monsoon birds, which throng mangrove forests in the Bhitarkakina National Park for their annual nesting, has dropped this year much to the worry of forest officials.

Though the visit of local migrant birds has re-established Bhitarkanika as one of the prominent heronries of the state, their headcount has found lesser number of visitors this time.

The most worrying feature of annual headcount drive that had been conducted from August 23 to 30 was that the seasonal birds skipped visiting Bagagahana heronry. "Bagagahana played host to hardly few hundreds of monsoon birds, while the birds were found to have preferred the nearby Mathadia wetland site for nesting," said Rajnagar mangrove (wildlife) divisional forest officer Prasanna Kumar Acharya.

"We are yet to ascertain the exact cause of birds skipping Bagagahana for their monsoon sojourn. Lack of human interference, ideal climatic condition, cool breeze and the river system always attracted the birds towards Bagagahana. The department is mulling over entrusting ornithologists to make a study on factors for birds' disinclination towards Bagagahana," he said.

As many as 91,224 birds were counted at the newly found heronry in Mathadia. Of these, 39,780 were adult, while 51,444 were chicks. As many as 19,890 nests were spotted on 1,911 treetops, according to the latest census report.