It is becoming increasingly clear that clear that local amphibian populations can suffer highmortality due to animals falling into roadside drains, particularly during their spring movements to and from spawning sites. For example:-
Perth and Kinross (https://www.wildlifeextra.com/go/news/gullypots.html#cr),
Madingley, in Cambridgeshire (https://www.toadrescue.co.uk/migration)
See also the Wild Britain Forum on this subject (https://www.wildaboutbritain.co.uk/forums/reptile-and-amphibian-forums/50297-frogs-and-newts-storm-drain.html)
The common toad is particularly vulnerable to this problem due to their tendency to spawn at a relatively small number of suitable ponds/lochs/reservoirs and migrate in to these locations from relatively distant feeding and hibernation sites. In urban and semi-urban areas, this means they often have to negotiate roads with drains and kerbs along the way. The risk of being squashed by passing cars is obvious but it is now believed that the numbers perishing in roadside drains can be much greater. The animals find it difficult to climb the steep face of the kerb and instead walk along them before inevitably meeting a drain, where a proportion will fall through the gratings. Once in the drain many (sometimes all) are unable to escape and either drown or slowly starve.
Caption: Toad heading for a spawning pond, Kirkintilloch
Caption: This model is safe but normal-sized toads can easily slip through the grating.
Work is being done to study the scale of the problem in a number of areas, notably Perth and Kinross (involving the Tayside ARG) and at Madingley (Cambridgeshire). We in CARG felt that we should be contributing towards this effort by investigating the problem of amphibians in drains in our area. This spring therefore, the group is trialling a project to locate problem “black spots” and try to estimate the numbers of toads and other amphibians that might be falling into the drains.
CARG intends to use the information gained to lobby the relevant local authority roads departments to adopt measures to prevent or reduce the impact on local amphibian (particularly toad) populations. Several mitigating measures are possible including “wildlife kerbs” (hyperlink), kerb ramps and “bridges” across the drain gratings, but all would require the co-operation of the local authorities. This project will, hopefully, give us the ammunition to obtain this….possibly with the aid of strategic publicity.
Our broad approach is as follows:
STAGE 1: Identify possible mortality hotspots through information we can gather from the local biological record centre (the Glasgow Museum Biological Record Centre – GMBRC) and from CARG members. The site we would like to look at in the first nstance are listed in the table below.
These are just the sites we know about however, if you know of other places where toads cross a road with kerbs and drains in the early spring, then please let us know.
STAGE 2: Reduce this list to remove those sites where a problem is unlikely, e.g. where there are no roads with kerbs and drain close to a likely spawning site.
STAGE 3: Monitor the remaining sites during the toad spawning season to see if there is actually a problem.
Caption: the danger is obvious
Gathering the Information
We would appeal for the help of CARG members (or indeed anyone who is interested), to help out with any aspect of the project. Even if you can just spare an hour or two to do a Stage 1 (daytime) or Stage 2 (evening) visit to any of the sites below that are in your area that would be a big help.
Stage 1 above, has already been done. We have searched all the information we have to hand, in order to produce the list of 14 sites in the table below. These are all places where there has been evidence of toad breeding - including multiple sightings during Feb-April, mating individuals seen, or else spawn or tadpoles seen.
Stage 2 will involve checking out each of these places to determine if there are roads with kerbs and drains nearby (within 200 metres). These Stage 2 surveys can be done during the daytime at any time between now and the end of the toad spawning season (late April).
CARG Support. The group will provide volunteers with a map of their chosen site and a simple form to complete with information on the location of kerbs, drains and possible breeding ponds/lochs/reservoirs. This information will allow us to ignore sites where the toads are not likely to fall into drains.
|Table 1: Sites at which amphibians are believed or known to come in to contact with drains.|
|Site No.||Site Name||Location/Details||Grid Ref.|
|1||Baggie Minnie Pond||Clydeford Road, Carmyle, South East Glasgow.
Known spawning site close to road/drains.
|2||Cardowan Moss: Moss Pond||100m north of Mosswale Road, Craigend, East Glasgow.
Known breeding site 500m east of Hogganfield Loch.
|3||Castlehill||Bearsden, by Roman fort off Duntocher road.
Likely breeding area, although pond not yet located.
|4||Cledans Burn, Pond 4||270m north-east of "goals" 5-a-side, great Western Road, between Clydebank and Drumchapel.
Likely breeding site: Mating toads reported.
|5||Dams to Darnley Country Park "main Pond"||300m south west of Darnley Hill.
Known breeding site close to roads and drains.
|6||Maxwell Park pond||Maxwell park south side of Glasgow.
Known Breeding site close to roads and drains.
|7||Kilmardinny Loch||Bearsden, Glasgow.
Roads/drains surrounding the loch.
|8||Dougalson Golf Course Ponds (2)||500m south-east of Craigmaddie reservoir, Milngavie.
Known breeding site with possible road/drain hazards.
|9||Queen's Park Boating Pond||Queens Park, Glasgow.
Known breeding site, close to road/drain hazards.
EVENING VISITS MAY NOT BE POSSIBLE.
|10||Robroyston Park Ponds (2)||Robroyston park, Glasgow: 120m east of Robroyston road.
One known and one possible breeding site within 150m of roads.
|11||Rosshall Park Pond||Posshall Park, Crookston/Pollock, Glasgow.
Road and drain hazards within 200m along 1736 Crookston Road and within hospital grounds.
|12||Tanoch Loch||Milngavie, East Dunbartonshire/Glasgow.
Likely though unconfirmed breeding site, close to road and drains.
|13||Lindsayfield Road, East Kilbride||Applegate Drive off Lindsayfield Road, East Kilbride.
Road and drain hazard close to breeding site.
|14||Broom Pond||Broom/Whitegraids, Newton Mearns, East renfrewshire/Glasgow.
Likely (unconfirmed) breeding site, close to road and drains.
Stage 3. This will focus on those sites where there is a potential problem. These sites will be checked at least once during the toad spawning season (in the Clyde area this is usually early March to mid April), in order to determine whether toads are falling into the drains. Each monitoring visit is best undertaken during the first 1-2 hours after sunset, when most toads are moving towards their spawning sites. The aim of these visits is to count moving toads (and other amphibians) and to mark their positions on a map, so that we know exactly which drains are the problem. This will allow us to pinpoint the best locations for preventative measures to be installed (e.g. lowering kerbs, kerb ramps or “wildlife kerbs”).
Needless to say, any animals seen attempting to cross the road will be carried across, thus avoiding drains and cars completely.
CARG Support. The group will provide volunteers with maps and a simple recording form to complete. We will also provide all equipment needed, including a HiViz vest (for safety near roads at night) and a torch.
Caption: Volunteers will be provided with basic equipment for evening visits
Note that we will require all volunteers to be accompanied by at least one other person during night-time survey visits. If you can’t persuade anyone to accompany you on an evening Stage 3 visit, let us know and we will arrange someone from within the group to join you.
As can been seen from the table below, there are 14 sites in the wider Glasgow area where we either know or suspect toads may be breeding close to roads. So please take a look at these and decide if you might be able to check out any of these that may be in your area.
Towards the middle of February we will be posting on the CARG website, a list of “Stage 3 sites” – i.e. those where the Stage 2 visits have suggested there may be a problem. These will be the locations where we would like to arrange at least one evening visit to look for/count/map migrating toads and other amphibians.
If you would like to participate in this valuable conservation project, please let either Erik Paterson (firstname.lastname@example.org) or John Sweeney (email@example.com) know as soon as you can and we will guide you from there.
Caption: Over twenty dead toads retrieved from a drain at East Kilbride
Erik Paterson, CARG Secretary