Our Adventure to Caroni Swamp...By Mhairi

A few expedition members including myself were invited by a friend of Professor Roger Downie to help survey Caroni Swamp for aquatic snakes. This friend was John C. Murphy – an expert on Trinidadian reptiles, and author of ‘Amphibians and Reptiles of Trinidad and Tobago’. Also present were two PhD students as well as a film crew following John for a documentary called “Bush Diary”. On arrival to the boat dock we were assigned roles including depth measurement and collecting water temperatures, my role was to measure the salinity of the water at set intervals using a hydrometer. It was dark when the boat set off, so using our head torches we scanned the glassy surface of the swamp, observing intently for any signs of movement. John instructed us to scour the mangrove engulfed banks as we were to be looking for any one of three species of aquatic snake, nets at the ready we waited patiently.

Throughout our journey the boatman spotted a Cook’s tree boa (Corallus ruschenbergerii). As the boat drew near to the tree in which the snake was resting, one of the PhD student reached out and grabbed the snake, after a bit of a kafuffle it was clear the snake was around 1 metre long. In its defence the boa had bitten the PhD student and emitted a foul smelling odour, the smell lingered in the air whilst John did a piece to the camera. Although not an aquatic snake, this find was crucial as John is collecting research to update his book, published in 1996, and is still used by Trinidad expedition students to this day.

Snake capture...

John C. Murphy handling the snake...

Snake released...

After taking a salinity measurement of 34 John exclaimed that aquatic snakes prefer brackish water with a salinity rating of around 12, so the boat about turned and we headed back towards the dock. Bright white eyes reflected our torch light in the pitch black and under further investigation we saw that camen, members of the crocodilian family, hiding in amongst the vegetation, they swam with their long snouts above the water and almost as soon as they had appeared they sank below the dark water again, the boat sped off. The journey was quiet, it had to be so as not to scare away the snakes, however, every now and then the silence was broken by the call of a frog, or a cricket or the churning of the boats engine. It was peaceful, and even though we dismounted the boat having not found any aquatic snakes, we gained a beautiful moon lit tour of Caroni swamp and witnessed a great naturalist in action.