Passing with flying colours as native bird raises young on Pulau Ubin

After years of trial and error, efforts to get the blue-throated bee eater - a bird species under the National Parks Board's Species Recovery Programme - to nest here have finally borne fruit.

Yesterday, NParks said that 21 instances of successful nesting have been recorded, with the current breeding season still ongoing.

Group director of conservation at NParks Lim Liang Jim told The Sunday Times that while the birds are native to Singapore, they rarely nest as sand banks and high river cliff banks, where the birds typically like to nest, are hardly present here.

Since 2016, a site in Ketam Quarry - a disused granite quarry - has been converted into a bird nesting area that caters to the different nesting requirements of three targeted bird species, including the blue-throated bee eater.

The birds dig holes in sand banks, which they use as nests.

Mr Lim said: "We looked at what conditions were needed when they were breeding overseas - sand banks and cliff banks - so we decided to pile up a mound of sand.

"From then on, we went through several years figuring out what was the optimal way to arrange the sand so that the birds are happy to use it."

Mr Lim said several ways were tried, such as adjusting the gradient of the mound. "We even put in plastic tunnels for them, to encourage them to explore, but they didn't seem to like it."

After several rounds of trials, those working on the breeding site found last year that a mound of sand about 3m to 5m tall was stable enough for the birds to feel comfortable digging nests in it and laying their eggs.

The angle of the mound's slope also mattered, said Mr Lim, who added that at a gentler slope, the birds could feel threatened that predators would climb the mound and steal their eggs.

After pairs of birds had nested, equipment was brought in to monitor the success.

"When we felt certain that there were chicks inside the nests, we waited for the parents to fly away and we went in with an endoscope to see how many eggs were laid, how many hatchlings there were," he said. "We have a lot of very cool footage of them bringing back food for the babies, having the babies come out for the first time and endoscope videos of the babies moving inside the nest."

NParks also said its species recovery efforts have benefited two other bird species - the baya weaver and the red-wattled lapwing.