A five-banded gliding lizard and a slender squirrel are animals you would not be able to find in Singapore's local parks.
But if you are lucky, you may chance upon the flying lizard or see the slender squirrel in the nature reserves - the only places in Singapore where these animals can be found.
Last Saturday, some 20 people on a nature walk caught their first glimpses of these animals at the MacRitchie Nature Trail, a gateway to the Central Catchment Nature Reserve.
It was one of a series of walks started by different individuals who have come together to cultivate an appreciation for the reserve, which could be affected by the building of the new Cross Island MRT Line (CRL) that will connect Changi to Jurong.
During these walks, the guides point out the flora and fauna unique to the reserves. They also give short history lessons on some of these plants, for example, how Tampines town was named after the Tempinis tree.
"With knowledge, people can develop more respect for nature and not be blase about abusing the environment," said Mr Subaraj Rajathurai, 50, one of the guides on last Saturday's walk.
The walks aim to point out the differences between parks and nature reserves - why the latter need to be protected, and the biodiversity that could be lost with the construction of the MRT line.
Parks, said Mr Rajathurai, a wildlife consultant, contain a smaller element of nature, whereas nature reserves are "original ecosystems" that support "a tremendous diversity of life".
These include fauna and flora, such as the Seraya and Jelutong trees, that can be found only in "good forests" - primary or mature secondary forests.
The four-hour walk on Saturday was also led by conservationist Tony O'Dempsey, 52. The next walk will be on March 8.
One participant, experiential learning specialist Jean Lau, 37, said: "Subaraj and Tony's knowledge has benefited my understanding of nature."
The walks were started last August in response to an earlier announcement by the Land Transport Authority (LTA) about the construction of the new CRL. Slated to be ready by 2030, the 50km line will span almost the entire length of Singapore.
Last September, the LTA said it will call a tender for a consultant to carry out an Environmental Impact Assessment (EIA) to ascertain how the line could affect the Central Catchment Nature Reserve.
Responding to queries, LTA said it is "working towards calling the EIA tender in the first quarter of this year".
Environmentalists said it is likely to be called by the end of this month.
To aid the consultant in carrying out the assessment, a group of nature lovers has submitted a 120-page collation of research on the reserve's ecology to the LTA.
The LTA said the report, together with an earlier position paper submitted by the Nature Society (Singapore), will be included in the EIA tender as reference materials for the bidders.
It added that the findings of the EIA, when completed in 2016, will be taken into consideration with other factors such as "travel times, implications to developments in the vicinity and costs" to "better inform the Government to make a decision on the alignment of the CRL".