A possible crocodile sighting over the weekend resulted in water activities being suspended in the Marina Reservoir.

While a crocodile sighting is quite rare, the Animals Concerns Research and Education Society (Acres) says that rescue cases involving reptiles - snakes, turtles and monitor lizards - are the second most common they encounter, after birds.

Pythons are opportunistic animals. They tend to be attracted to areas with rats, but will also prey on small animals like cats when they venture into their range.

The well-publicised sightings do not necessarily mean an increase in the number of animals venturing into urban areas.

"People are so well-connected nowadays, and will film the sightings and share them online," said Mr Kalai Balakrishnan, deputy chief executive of Acres.

Here are some recent cases:

Nov 26, pangolin at National University of Singapore, University Town

The shy pangolin is not often sighted, but two were seen this week. Acres gets about two or three calls a month to rescue the scaled mammal.

On Saturday, one was found climbing some steps at University Town, to the delight of students studying for their examinations.

Nov 26, "crocodile" at Marina Reservoir

Water activities were suspended after a possible croc sighting, but preliminary investigations indicate it is most likely a monitor lizard.

Nov 25, python at Nanyang Technological University (NTU), Hall of Residence 16

A slithery encounter at NTU reported in the Nanyang Chronicle, this was second reticulated python seen in the school this month.

Nov 22, pangolin at NTU, Hall of Residence 7

It was released in a forest just a short distance away from where it was found.

Nov 19, python at NTU, Nanyang Heights

NTU cat lovers were mourning the loss of one of their cats, which was eaten by a python, according to the NTU Cat Management Network.

The python was taken away, apparently by pest control officers.

Nov 18, crocodile at Lim Chu Kang fish farm

An estuarine crocodile got into a tight spot at a fish farm last week too. The 2.5m-long native reptile just couldn't wriggle out of the shed he crawled into, and had to be rescued by Acres.

Oct 18, peacocks at Sentosa

These colourful fowl were captured by a Straits Times reader while showing a foreign friend the sights of Singapore.

Squirrels and peacocks are some of the wild animals you can find on the island, and they are one of the reasons the speed limit there is a leisurely 40kmh.

Oct 12, python at NTU, Hall of Residence 15

Another python last month at NTU, which is fairly close to forested areas.

July 26, python at Ang Mo Kio coffee shop

Pythons often appear in drains, and it's not unusual to find them in areas with lots of food, and therefore rats.