Woodlands housing estate planned next to Marsiling Park

The study recorded 154 animal species within the 14.4ha survey area, including 15 of conservation significance.

Among them are the straw-headed bulbul, the smooth-coated otter, the changeable hawk-eagle and the bamboo bat.

That said, only the bamboo bat and the long-tailed macaque were observed within the area slated for housing, said the report.

It added that animals within the 14.4ha study area have already been exposed to prolonged disturbance from ongoing construction due to the redevelopment of Woodlands Checkpoint and other nearby developments.

The report said the continued presence of animals with conservation significance despite these disturbances suggests that the species in the area are relatively tolerant of disturbance.

However, the report warned that bird species of significant conservation value like the straw-headed bulbul, as well as the Sunda pangolin, are expected to experience major negative impacts to their movement due to the proposed development.

This is because such birds are highly dependent on continuous or well-connected forest canopy, while pangolins are highly sensitive to the fragmentation of their natural habitats and urban encroachment.

Meanwhile, 156 plant species were recorded within the study area. Eleven of them were of conservation significance, though only three species fall within the proposed housing site.

The report recommended several measures to mitigate the environmental impact of development in lieu of retaining parts of the site for conservation.

During construction, the report suggested managing the use of artificial light at night to reduce disturbance to animals and planting fast-growing native trees and shrubs to improve connectivity for wildlife, which was highlighted as a key concern.

The report recommended creating linear green spaces along the new development’s eastern and western edges.

It said this would facilitate the movement of wildlife between green areas in the north, such as the Mandai Mangrove and Mudflat Nature Park, and green spaces in the south such as the Mandai Planning Area and the Central Catchment Nature Reserve.

Another suggestion was to include biophilic water features in the new development.

Biophilic design aims to connect building occupants more closely to nature through elements like natural lighting, materials and ventilation to improve overall well-being.

According to the report, nature groups were engaged on June 30 to share findings from the study and discuss proposals to mitigate the environmental impact of development.

It added that the report was further revised and finalised based on feedback received during the session.

HDB has published the environmental study on its website. The public can provide feedback to the agency via an online form until Dec 7.

Tony O’Dempsey, a member of the Nature Society of Singapore’s conservation committee, said there is marginal value in retaining the area with moderate ecological value as most animals and plants of conservation significance are located in exotic-dominated and abandoned land forests that lie outside the area.

On the mitigation measures proposed in the report, O’Dempsey said the proposed linear green strips will have limited effectiveness in connecting wildlife because they are only about 2m to 3m wide.

Peer-reviewed scientific papers recommend at least 10m for avian connectivity and roughly 60m for small mammal connectivity, he added.

He suggested further facilitating the movement of wildlife by reimagining a stormwater drain to the east of the study site in the style of national water agency PUB’s Active, Beautiful Clean Waters programme.

The programme aims to spruce up water bodies here and transform concrete canals and drains into areas that can be used for community events and recreation.

Ho Xiang Tian, co-founder of environmental group LepakInSG, said that while the area slated for housing is currently not the most biodiverse, development there will affect wildlife connectivity between the northern part of the Central Catchment Nature Reserve and the Mandai Mangrove and Mudflat Nature Park.

Separately, Muhammad Nasry Abdul Nasir, executive director of Singapore Youth Voices for Biodiversity, said he does not expect the ecological impact of the development plans to be significant, but is concerned about the potential impact they might have on mangroves downstream, such as the Berembang and Dungun Air trees.