SINGAPORE - Christmas might be over, but pine or fir trees from the festive season could still be useful, at least for Justin Beaver and his other furry pals at the Singapore Zoo and River Safari.

The Wildlife Reserves Singapore (WRS) has appealed to the public to drop off their live Christmas trees at the Singapore Zoo's open-air carpark from 9am to 2pm on Saturday (Jan 5).

The trees will be used to give some of the animals at the zoo and River Safari an avenue to explore new and unfamiliar objects, just as they would naturally in the wild. The WRS told The Straits Times on Friday that this process, called animal enrichment, helps boost the animals' well being.

The WRS added that it often uses natural materials, such as leaves and branches from trees in its parks, for animal enrichment.

Several WRS employees shared the appeal for Christmas trees informally in the past week, including veteran zookeeper Kumaran Sesshe, who wrote a Facebook post last Saturday from the perspective of River Safari star Justin Beaver.

He wrote: "Hi, I'm Justin Beaver! My animal friends and I at WRS are always looking for something to gnaw, scratch, sniff and play with."

He added that those with "real, lush and green" Christmas trees to spare after the festive season could donate them to the WRS.

ST understands that this initiative by the WRS started on a small scale in 2017 for Christmas, but keen interest online has helped to spread the word this time.

The WRS said that when its staff noticed that many people were disposing of their trees after Christmas, they felt that these trees, with their pine scents, would make good enrichment devices for the WRS' animals. This is because the trees are something that they are not usually exposed to in captivity, the spokesman added.

According to American non-profit organisation Beaver Institute, beavers chew on wood to help keep their teeth sharp and prevent them from growing too long.

This is because beavers, just like all rodents, have teeth that do not stop growing.

A hard orange enamel on the front side of their incisors and a softer white dentin on the back of these teeth enable them to sharpen their teeth on their own as they chew on wood.

And as beavers chew, the softer part of their incisors tend to wear off faster, creating teeth with chisel-like cutting surfaces.

More people here have indeed began opting for a real tree in their homes, according to an ST report last month.

Nurseries here noted an increase in sales for the trees in December, as compared to past Christmases, which they attribute to more young families getting in on the tradition of buying a real tree.

Some have also made the switch from artificial trees in a bid to reduce their carbon footprint.

According to the British environmental consultancy Carbon Trust, an artificial tree would need to be reused at least 10 times for its environmental impact to be lower than that of a real tree, which is used once.

Around two-thirds of an average artificial Christmas tree's carbon footprint is from the plastic that it is made from, which is produced from carbon intensive oil.

In addition, how a fake tree is disposed of is also crucial.

A 2m-tall real Christmas tree, with no roots, has a carbon footprint of 16kg carbon dioxide equivalent (CO2e) if it ends up in landfill, said the organisation.

However, an artificial one of the same height will leave a carbon footprint of around 40kg CO2e if discarded in the same way.

Several Facebook users have since expressed their interest to contribute to the cause on Mr Kumaran's post, with a few suggesting that they could arrange for a moving company to help transport the trees from their homes as a group.