Nature thrives in Singapore, and more people are interested in getting acquainted with the flora and fauna here.

Slots at almost all nature activities launched by the National Parks Board (NParks) to mark the International Day for Biological Diversity this Sunday - including a guided tour at Fort Canning Park, a firefly survey in Pasir Ris and a field trip to offshore Pulau Ubin - have been snapped up.

But those interested in learning more about mangrove habitats, and the plants and animals that call them home, can still do so.

NParks is organising a free guided walk at the Pasir Ris mangroves tomorrow.

There will also be a photo exhibition held at Sungei Buloh Wetland Reserve - which comprises 202ha of mangroves, mudflats, ponds and forests - from Sunday to June 30.

More than 17,000 people are expected to take part in over 10 activities organised by NParks this year as part of Biodiversity Week, which is being held for the second time.

The events are being held in various parks and nature reserves across the island in the lead-up to the International Day for Biological Diversity, which is celebrated worldwide to increase awareness of biodiversity issues.

NParks is also reaching out to schools. Secondary school students can take part in a photography challenge until Sunday, while pupils from 22 primary schools took part in a five-day nature challenge, which involved exploring butterfly trails within their school or penning a nature-inspired poem.

Pre-schoolers, too, learnt about native wildlife through a storybook and a video that told the tale of Kaya the otter and how it travelled through canals in search of a new home, a story which mirrors the actions of some of the island's own otter families.

Ms Cindy Lee, principal of PCF Sparkletots Pre-school @ Yuhua Blk 233, said: "The localised resources help children better relate to the wildlife that can be found in our backyard, thereby cultivating in them an interest in conserving them."

Dr Lena Chan, group director of NParks' National Biodiversity Centre, said the board is encouraged by the enthusiastic response from members of the public and schools. "This is testimony of their interest in playing an active role in conserving our rich biodiversity and sustaining our City in a Garden vision," she said.

• For more information on Biodiversity Week, visit www.nparks.gov.sg/biodiversityweek