Great Crested Newts in the OU pond

A population of great crested newts is present in the pond situated on the Open University Campus, between the library and the Church car park. Records show that the pond has been in existence for at least seventy years and so it is probable that the newts were also here long before the Open University was conceived. The newt population has been monitored, using various techniques since 1988.

Newts typically spend the winter on land, within several hundred metres of their breeding pond. In the spring they migrate towards the pond. During this annual migration it is possible to sample much of the newt population by capturing animals in pitfall traps. A low fence put up around the pond guides the newts into the pitfalls. Once in the water, the newts can also be captured by careful use of funnel traps.

Recognition of Individual Newts

The unique patterns of black spots on the orange/yellow ventral surface have been used to recognise individual newts. Records are made by photocopying anaesthetized newts. Newts are also weighed and various body size measurements made.
Intensive monitoring of this nature provides us with two sorts of information:
1. Data on growth and condition of individuals.
2. Data on population dynamics.

Measurements of individuals has allowed me to investigate the relationship between the crests that develop on the back and tail of males (below) during the breeding season. Males that are in better body condition when they arrive at the pond go on to develop higher crests later in the year.


Global Declines

Recent concern over declines of amphibian populations from many different countries has lead scientists to consider whether these are symptomatic of a global problem. However, before we can tell whether any particular decline represents a departure from the natural course of events, we need to be able to find out what sort of population fluctuations are 'normal'. The only way to do this is to carry out long-term studies.

The OU newt population appears to be relatively stable, compared with the enormous fluctuations that are now being recorded in other amphibian species. However, this graph is deceptive. Records of individuals have shown that for the first five years of the study, survival of adults was relatively high - about 80% of the breeding population survived from one year to the next, but there were few new recruits. However, the largest increase in population size (1993-94) was actually accompanied by a drop in adult survival to only 30%. So, 1994 saw a massive influx of first time breeders, but also a disappearance of many of the old familiar faces (or bellies in this case).

Conservation Status

Although the great crested newt is the most rapidly declining British amphibian, it has a species range over much of Britain, and populations occur in many ponds in the Milton Keynes area.

Great crested newts are protected under the Wildlife and Countryside Act (1981). It is illegal to handle or otherwise disturb great crested newts without licencing. The work described on this poster has been carried out by John Baker under licences from English Nature.

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