The old farm pond was an important breeding site for amphibians - frogs, toads and newts - but throughout the twentieth century the number of these ponds has declined dramatically with changes in farming practice. The good news is that some new ponds are being created by farmers and landowners, offsetting the loss of traditional habitats.
It was the potential importance of these new ponds as habitats that led Professor Tim Halliday of the DATF, and his colleague John Baker, a post- doctoral research fellow, to take a closer look. Poking around farm ponds in Bedfordshire, Buckinghamshire and Northamptonshire, they produced a detailed survey of the types of creatures living in them.
The results of their research, they hope, will lead to changes in the way new ponds are sited.
"What we found was that, although the overall amphibian numbers are similar between new and old ponds, the species composition is different. There were significantly fewer newts, particularly great crested newts, which are among the rarest and most-threatened of British amphibians."
Newts, it appears, do not like long-distance walking. While frogs and toads are willing to travel at least 950 metres to make their home in a new pond, newts were found only in new ponds within 400 metres of their existing habitat.
The presence of fish and waterfowl was also bad news for newts, the survey found, and particularly for the great crested newts, which never lived in fishponds. Fish and waterfowl are more likely to be a feature of new ponds, which are often created for recreational and sporting purposes, rather than of traditional ponds, which were mainly used for watering livestock.
Says Tim: "New ponds on farm land can provide suitable habitat for amphibians. But to benefit newts, they should not be stocked with fish or subject to heavy waterfowl use. If fish and waterfowl are the purpose of a pond creation scheme, secondary ponds can be built as part of the scheme and set aside for newts. New newt ponds should also be sited within 400 metres of existing newt ponds."
Newt-friendly pond construction schemes can have wider benefits, he says. "Areas of high pond density that are favourable to newts, are also associated with greater plant diversity. So a pro-active conservation strategy for great crested newts could use this legally-protected amphibian as an `umbrella species' under which other pond organisms could benefit."
More information about the work of the Declining Amphibians Task Force is available on the web at www.open.ac.uk/OU/Academic/Biology/J_Baker/JBtxt.htm.