"Alien" species may be found anywhere - in reservoirs, gliding across trees, or even in a neighbour's home ("Tracking non-native animal species here"; Nov 4).

Wherever they are, non-native animal species pose a threat to our local environment, and we can do more to address the issue.

A significant portion of introduced species comes from the pet trade.

Animals such as the red-eared slider and alligator gar have been abandoned by owners in ponds and reservoirs when they grow too big.

These animals compete with our native residents for food, nesting spots and other essential resources.

To tackle this problem, we can start by addressing the root cause.

Pet shops and animal welfare groups can educate potential pet owners on the maintenance required in caring for a pet, and ensure they have a clear idea of how long these animals can live and how big they can grow.

Having realistic expectations can reduce the number of non-native pets abandoned.

We also have to do our part.

If we see people releasing non-native animals into nature reserves or reservoirs, we should inform them that such an act is prohibited under the law.

More importantly, we should not buy pets on impulse.

With Christmas approaching, it is a good opportunity to remind our family and friends not to buy pets as gifts, unless there is a specific request and the necessary research has been done.

Together, we can minimise the invasion of non-native species and protect our native biodiversity.

Tan Jit Yee (Ms)