Worcestershire Record No. 2 April 1997 p. 3

A ROUGH GUIDE TO THE STATUS OF AMPHIBIANS IN WORCESTERSHIRE (1997)

In Worcestershire we have five of the six species of native amphibians; these are the common frog, toad, great-crested, smooth and palmate newts. The natterjack toad has long been extinct within the county.

The rarest of our county's amphibians is the palmate newt. Nationally it tends to be confined to ponds with low nutrient levels and is the only species of newt capable of tolerating low pH conditions associated with acidic rock formations. Its county strongholds are within the Wyre Forest and near the Malvern Hills. Other unconfirmed reports of palmate newt have come from the Knapp and Papermill Reserve, Hartlebury Common and the Chadwick Estate.

The great-crested newt is specially protected under the Wildlife & Countryside Act because England and Wales is the international centre of distribution for this species. Nationally this species has been in steady decline because of the losses of country ponds and their general decline quality. However, they are still widely distributed within Worcestershire, although its density of occurrence varies according to geology and land-use patterns. All three species of newt cannot tolerate prolonged fish predation. Typically crested newts favour ponds which hold water throughout the summer months and are not densely shaded and silted. They also show a preference for moderately eutrophic ponds with a neutral to slightly basic pH. It is therefore not surprising to learn that, because of the water's mild alkalinity, they are more commonly found in ponds on the Mercia Mudstone and Lower Lias clays in the county. A blanket pond study of the Warndon area of Worcester covering 4.2 square kilometres located 60 pond and wetland sites within this small area. Despite the fact that over half were shallow and ephemeral or heavily silted, great crested newts have now been located within 21 sites within this small area. It is probable that the great-crested newt is as common within other parts of the county which bear similarities to Warndon. More studies will have to be undertaken before we know the exact status of the great crested newt within the county. However, indications to date do suggest that Worcestershire ponds are particularly significant for great crested newt.

The smooth newt is the most common newt within the British Isles and within the county of Worcestershire. It is found in similar conditions to the great-crested newt, although it is better suited to smaller and ephemeral type ponds. It is also better at colonizing new sites than the above species. It readily colonizes garden ponds.

The common frog has declined within the rural landscape mainly due to pond losses, but has increased within urban areas due to people building garden ponds. Despite the changes in agriculture, the overall population trend for this species is up both nationally and locally.

Swapping of frog spawn may be partly responsible for this trend. However, the worrying spread of the viral disease known as 'red leg' is almost certainly encouraged by the swapping of frog spawn. To date there have been few reported incidents of this disease in the county, but as a precaution people are advised not to translocate frog spawn. Recent results from the Wyre Forest indicate that there has been a steady decline of frogs over a 10 year period, so far the reasons for this decline have not been explained. Low frog recruitment has also been noted from other ponds on acidic ground in the west midlands.

The common toad is also broadly distributed within the county. Once established within a breeding site a sizable colony of toads develops. Where conditions are right thousands of toads may use a particular breeding site. They may disperse a mile or more from their breeding pond to seek out new feeding grounds. There is a tendency therefore for distribution to be clustered around important breeding sites with apparently suitable areas absent of toads. A massive colony of toads exists at private pools at Church Lench, this site is known to support over 10,000 breeding individuals. The author has also been informed of other large colonies in the area. Large populations of toads (and indeed other amphibians) can only develop if terrestrial conditions are suitable. In order for toads to over-winter successfully they must find frost free conditions. Soil and geology is particularly important. One can only assume that the fertile soils of around Church Lench are ideal in this respect.

Although the natterjack toad is now extinct within most inland counties a recent record came to light to show that it may have been present within Worcestershire in the 19th Century. A party from the Worcestershire Naturalists Club found what they describe as "an uncommon Batrachian the natterjack toad" between Hanbury and Piper's Hill Common.