The 'intelligent nests', with cameras, sensors and scales, give researchers new ways to monitor these once-endangered birds.

The project, which began five years ago to study the birds' breeding and nesting, has been a success according to the researchers involved.

In previous years, researchers from the National Parks Board, Jurong BirdPark and Nanyang Technological University mounted artificial nesting boxes high on trees and equipped them with simple infrared cameras to monitor each breeding pair.

The Oriental Pied Hornbill are known to be picky about their nesting sites, laying their eggs in cavities in old and diseased trees, high off the ground.

This breeding season, they have added two 'intelligent nests' kitted out with temperature and humidity sensors, weighing scales to monitor the chicks' growth and high-definition cameras which can zoom in to great detail.

'They are like condominiums, with a security system,' quipped Mr Robert Teo, NParks' assistant director for Pulau Ubin.

The Singapore Hornbill Project is a collaboration between NParks, NTU, the National University of Singapore, Wildlife Reserves Singapore, which oversees Jurong BirdPark, and other sponsors.

For its pioneering studies of hornbill breeding, the project won a prestigious international award for achievements in avian research and conservation last year.

Project consultant Marc Cremades, a French researcher who initiated the project, believes this is the only study worldwide to monitor wild hornbills in their nests during breeding season.

The group first placed nesting boxes on mainland Singapore last year, and hope that future generations of young hornbills will move in.

Read the full report in Thursday's edition of The Straits Times.