The Amphibians in Drains Project was started in Perth and Kinross in 2010 after observations that a significant number of roadside gullypots contained dead amphibians and small mammals. Roadside gullypots are essential for road drainage but can act as pitfall traps when animals fall through the grid at road level, and once trapped it is unlikely the animals will be able to survive for any length of time. It was identified that a more robust study to ascertain the scale of the problem was required. The Amphibians in Drains Project was born!
A large common toad wedged in a gullypot plug – escaping drowning, but with no way out.
The aims of the project were:
- To estimate the number of drains that may be affected across eastern Perthshire and, through extrapolation, across Perth and Kinross.
- To estimate the number of amphibians & mammals that may be trapped.
- To record species of amphibian & mammals affected.
- To investigate if there is an association between adjacent habitat type and high numbers of trapped amphibians.
- To investigate if there is an association between proximity to ponds and high numbers of trapped amphibians.
Results from the survey illustrated that gullypots create a substantial problem for amphibians and small mammals. A total of 3007 animals were found in 1565 gullypots, which works out at an average of 1.9 animal per gullypot. From these results we can extrapolate that with 37,252 gullypots being found across the county, if an average of 67% (24,958) of these contain wildlife (with an average of 1.9 animals trapped per drain), the total number of trapped animals would be 47,421 across Perth & Kinross per year.
The survey showed that the majority of amphibians were found within 1km of a breeding pond. This information is significant for targeting road works involving gullypots or kerbs within a short distance of a breeding pond. If we were to target only these areas with a high incidence of trapped wildlife, this approach would ensure a low cost, high benefit solution.
Not all amphibians are as lucky as this rescued frog – but things are looking up.
In 2012 the Ranger Service started the Amphibians in Drains Pilot Project at Elm Drive in Blairgowrie, which involved replacing standard kerbs with wildlife kerbs, allowing wildlife to avoid the danger zone of the gullypot by following a recess in the new kerb. Consequent surveys have shown that these kerbs are working well, with far fewer animals falling into and drowning in the gullypots.
In 2015, working with the Tayside Biodiversity Partnership, ladders were placed in gullypots at a site in Lethendy, to enable wildlife which had fallen in to escape.