Research in to Amphibians
Great Crested Newt research
Since its discovery in 1984, the Little Wittenham newt population has been intensively studied. The site is unique for research into many aspects of great crested newt ecology because it contains a wide range of aquatic and terrestrial habitats, including a mosaic of mixed broadleaf and coniferous woodlands, rough grassland and arable land. Terrestrial ecology and migration, metamorph production and metamorph orientation have all been researched. There is also an ongoing monitoring programme.
Great crested newts are a protected species and all the work carried out at Little Wittenham is approved and licensed by English Nature.
Terrestrial Ecology and Migration
Before Robert Duff (1989) and Paul Franklin (1993) carried out research at Little Wittenham, little was known about the terrestrial phase and habitat requirements of great crested newts. The information gathered has provided an insight into triggers and habitats used for hibernation and the migration of adult newts to and from the ponds. Results have since been used as guidelines for terrestrial habitat requirements and management.
Metamorph Production
Recent work by Rachel Hayward has highlighted the unpredictability of the production of metamorphs (recently metamorphosed newts emerging from the pond for the first time). Numbers have ranged from 20 to 2000 metamorphs emerging from the ponds each year. Because great crested newts are so long lived and take up to three years to become sexually mature, changes in population dynamics may go unnoticed for many years. Adults may return to a pond year after year, but if there is no successful recruitment of new newts, the population has no means of sustaining itself and will become extinct.
Metamorph Orientation
Most work on orientation so far has focused only on the migration & homing ability of adults. Recent work at Little Wittenham, conducted by Rachel Hayward, has searched for clues as to how metamorphs (recently metamorphosed newts emerging from the pond for the first time) might find suitable terrestrial hibernation sites for their first winter.
Monitoring
Monitoring of the Little Wittenham population began in 1987, to assess the numbers of newts migrating into and out of the breeding ponds each year. It provides information on the abundance of newts that may reflect the effect of management and recruitment success. Eggs, larvae and aquatic adults have been monitored in the past, providing information on aquatic habitat use by the newts at different life stages, and the effects of management. Belly patterns have been photographed allowing individual newts to be identified if recaptured. This provides information for population estimates, migration movements, longevity etc
The current monitoring programme uses trough traps to capture newts moving to and from the ponds. It gives an index of population for adults, metamorphs and juveniles, and allows us to track changes in population.
For further information on our newt research programme, please contact us.
Common Toad Research
As part of a PhD research programme, Dorian Latham, of De Montford University, studied terrestrial habitat selection by common toads. Part of the work was conducted at Little Wittenham. In 1994, drift fences and pitfall traps were used to trap toads moving between different terrestrial habitats and the breeding ponds. Toad density was considerably higher in deciduous woodland blocks than in coniferous blocks, indication a preference for deciduous woodland. Latham also found that the home range of toads was much larger in the coniferous blocks; deciduous woodland offers more food so the toads do not need to travel as far to find enough to eat.
