There are a few species of terrapin that are present in our waterways. The most common is the red-eared terrapin. Many were transported from the USA as pets during the 'Teenage Mutant Hero Turtles' cartoon craze of the 1980s.
When the pets grew to the size of a dinner plate and developed substantial strength, many were irresponsibly released into the wild. This prompted fears for the health of local wildlife, as well as the terrapins themselves, which are ill-equipped to survive in the cool and damp British climate.
Terrapins, along with tortoises and turtles, are known as 'chelonians', meaning reptiles with shells. They are almost totally aquatic but need dry land to bask on during sunny days. Still waters and rivers in the midlands and southern England support the largest terrapin populations. Snapper turtles and European pond terrapins have also been spotted along our waterways.
It's unlikely that these animals are breeding, as terrapin eggs need to be incubated at 25 degrees Celsius for around 60 days in order to hatch. Anyone familiar with the British summer knows exactly how unlikely that is. However, with climate change, they could start breeding.