The two drains, designated A and B on the map, were quite dry, being completely choked with silt. All the animals removed from these were still alive with the exception of a female newt. All the others had water in them. Extricating amphibia from these was difficult as they tended to try and avoid capture by diving into the opaque water or retreating into the pipe at the side. This pipe presumably leads to the pond so in theory the amphibia may be able to reach the pond that way unless some filter or other blocking device was built in. On the other hand several of these drains had dead toads in them or else pairs in amplexus where the female had drowned. In some drains the side pipe was blocked.

With two exceptions all drains were 45 cm. square, the gap between the bars being 3.5 cm. The drains on the road to Kennel Farm, 2 and 3, were 40.5 by 35.5 cm. but the gap between the bars was the same.

The figures in the table suggest that the drains were indeed having a very serious impact on the toads and also harming frogs and newts. Two sets of factors, however, have to be taken into account.

First there are a number of gaps in the records which need explanation.

1. Our initial plan was to inspect the drains periodically and rescue any amphibia trapped in them. We made no attempt to visit the site at night for the two nights after our initial visit since it was cold and we assumed that the main run had probably finished. A casual visit the next evening proved that this was far from the case. Not only were there about 150 toads on the roundabout and verges but we could hear plenty of males calling in the fields who had still a fair way to go to the pond. After that we tried to visit the site every night but this proved impractical.

2. We badly underestimated the duration of the migration and mating period. This is discussed below.

3. Our timing was also erratic. This was partly because visits had to be fitted in with other things but we did not at first appreciate the scale of the problem. Commuter traffic into the estate finished about 2000 hrs but it was impractical to work in the car park until after 2200 hrs when the swimming pool turned out. Our initial visits were confined to the area of the roundabout since we assumed that most amphibia would be approaching from the east.


We did not inspect the drains on the route to the car park until March 20 and did not check those in the car park itself until later still. When we did so we found several toads trapped in drains and a number on the road. There seemed to be a second migration here, starting some two weeks after the main one at the roundabout. We did not notice many dead toads in the drains indicating that they had not been using that route for long. That is why visits after March 25 tend to be much later than those before.

Second, and more to the point, the site itself has a number of peculiar, though not necessarily unique, features which must be taken into account.

1. The pond is an altered, but still acceptable, established site. Other breeding ponds in the area which may have existed, have been destroyed by the development and consequent lowering of the water table - by about a metre according to an archaeologist we spoke to.

2. The routes to the pond are being constantly interfered with. Until this year toads approaching the pond from the east had only a footpath to cross. The archaeologists have now thrown up a large spoil heap along their excavation which has the effect of directing the toads either to the roundabout or on very long detour via the car park.

3. This may explain the long migration period. On March 20 we first saw a spent female toad leaving the pond and on March 28 drain B was empty for the first time. On the other hand the same evening found several toads in amplexus still making for the pond and there was enough calling and croaking to indicate that breeding was continuing. We fished a pair in amplexus out of a drain in the car park as late as April 4. A casual visit on April 22 found a pair in amplexus in drain B.