Predation of Amphibians by Leeches in the UK survey.
We Need Your Sightings! Leech Predation on Amphibians here on the Isle of Wight has been quite a regular occurrence for at least the past ten years. Often Amphibians are found in ponds with leeches attached which quickly overcome the animal resulting in its death. They are found around the eye sockets
and arm pits of the affected animals or in severe cases completely covered.
We first saw it when we were running an Exotic Pet shop and someone brought in a toad that had a beard of leeches and eye sockets full of them!. Since then we have seen numerous sightings on local groups or have been contacted for advice on treating the afflicted amphibians. It didn't register that this was not a widespread common occurrence. Having seen a post about a Leech "attack" on the Mainland UK in the Hampshire and Isle of Wight Amphibian and Reptile Group (HIWARG) by Pete West we realised we may have been witnessing a problem unique to our area, which could indicate perhaps the leeches doing the damage may be an invasive species.
Pete wrote.. "About ten days ago, someone in Devon found a toad with leeches completely covering both eyes and a few in its limb joints. After a couple of days of comments with nobody any the wiser, Steve Allain found a photo of a toad in a similar situation from the Isle of Wight from eight years ago. I tried tracking this case down, but was unsuccessful, but did find a natural history note on leeches in Tunisia predating on their native toads in a similar way. This prompted me to follow this up with the Non Native Species Secretariat who were very interested and have since been in discussion with ARC, ARG UK and Garden Wildlife Health (who investigate wildlife disease etc). I decided to post the story on HIWARG and DARN's FB page, along with a couple of other local FB pages in the hope the groups would do their thing and spread the news... I didn't think it would work so quickly, but in less than 24 hours Charis posted two photos of frogs covered in leeches, one of which she had in captivity. Since then emails and messages have been zinging back and forth between the two finders, GWH and the other agencies and samples of the leeches are on their way to be identified. We don't know if this is an unrecorded behaviour of a native leech or a new non-native species of leech as described from the Mediterranean. All will hopefully be revelead by GWH."
We know this is prevalent on the Isle of Wight so we would really like to build up a picture of how far this is occurring. If you have seen this first hand in Amphibians please take 5 minutes to fill in our survey form and all info will be passed to the relevant organisations.
Survey link here - https://forms.gle/rQUyvhR5QF9HXdwd7
What can be done to help the Frogs and Toads that are attacked by leeches?
If left untreated they will certainly die as their bodies become over taken by the leeches, you can seek help from a local vet who may be willing to attempt treating the animal or may decide the kindest thing would be euthanasia or you may be able to find a local organisation experienced in wildlife rehabilitation. We have successfully removed the leeches from amphibians in the past and will be happy to share what we have learned with any professional working in animal rehabilitation, just get in touch.
Are these Leeches a problem ?
We dont know! this could be a common occurrence that happens naturally in the UK at levels that go unnoticed or it could be a sign of an invasive issue emerging. We do have many species of Leeches in the UK and they all form part of the diversity of the natural fauna, Leech sightings in your pond are signs of an active healthy diverse range of wildlife. This is why data gathering is so important.