bullfrogs @ West Coast Park canal 31July2011

Was walking along the West Coast Park canal when something scampered down the canal embankment and dived into the water. At first, it seemed like a small monitor lizard as one would normally expect to see them in such areas near the Marsh Garden pond. However, the distinctive leg extensions as it swam away below the water showed it was obviously a frog and not a lizard. And it was a big frog. It swam towards the centre of the canal and floated in the middle for a while before submerging for about half a minute and reappearing a few feet away.

Walking further alone, there was another slightly smaller bullfrog on the canal embankment about a foot away from the water level. Some passing pedestrians startled it and it jumped into the canal water. It too swam towards the centre and floated there for a while. It cautiously made its way to the far side of the canal.

Walking along the side of the canal path, i had noticed that there was a half-filled plastic bag lying in the grass beside the path. It looked as if that had been the container for the two frogs. It was likely that someone had released the two frogs a few moments before I came across them. Unfortunately, the frogs had jumped into the canal filled with seawater. They would probably not survive in a saltwater environment. 

Strangely, both frogs had a little red-pink colouration from their nostrils to the tip of their upper lip. Unless such unique colouration occurs naturally, maybe this was artificially applied???

Bullfrogs are not native to Singapore and they are an invasive species which can outcompete native species of frogs.

Look here for more info about the bullfrog :
http://www.arcbc.org.ph/arcbcweb/pdf/vol2no4/33-34_invasive_singapore.pdf
http://www.ecologyasia.com/verts/amphibians/american_bullfrog.htm
http://www.wildsingapore.per.sg/discovery/factsheet/frogamerican.htm
http://animals.nationalgeographic.com/animals/amphibians/american-bullfrog.html
http://www.issg.org/database/species/ecology.asp?si=80
http://animaldiversity.ummz.umich.edu/site/accounts/information/Rana_catesbeiana.html