Article by Jen Le Blanc
The Great Crested Newt (GCN) is the most highly protected amphibian in Britain. Over the last few years, there has been much interest in learning more about their ecology and understanding their day-to-day living requirements.
Typically, GCNs start migrating to their breeding ponds in February or March. They prefer medium-sized ponds with plenty of submerged and emergent plants and 5-20% shading. GCNs also seem to do particularly well in areas where there are a number of ponds clustered within approximately 250 m of each other.
A complex courtship then begins, with males performing moves that have been given names such as the ‘Flamenco’ and ‘Head-bob’ in the open water. Males then deposit their sperm, which is collected by the female to fertilize her eggs. A female will lay up to 250 eggs each year, each one carefully folded into the leaves of surrounding plants. Newts suffer high mortality at this stage, especially if fish or waterfowl are using the pond. Larvae then hatch around 6 weeks later, and metamorphose into full juveniles within 16 weeks. Since GCNs will kill their own larvae, the young are forced to stay in areas of open water making them susceptible to even more predation by fish.
Adults start moving away from the pond around mid-summer, where they disperse to the surrounding terrestrial habitats for foraging and sheltering. Juveniles leave the pond a little later, generally in August or September. When out of the pond, newts need refuge habitat such as scrub, tussocky grassland or woodland as well as foraging areas rich in invertebrates. Ideally, this habitat would be free from dispersal barriers such as roads, large rivers and urban areas, and provide good connections between local pond clusters.
After a few months spent foraging, newts will search for winter hibernation sites such as crevices, tree roots, walls and mammal burrows. Almost all newts will be dormant between November and February. Mature adults will then start returning to breeding ponds, while juveniles tend to stay on land for 2-4 years until they are fully mature.
GCN populations have declined significantly over the past 50 years due to the loss of both terrestrial and aquatic habitats. Breeding ponds have been filled in, destroyed, polluted and misused while terrestrial habitats have been ploughed, sprayed and fragmented. In order to prevent further loss, we need to find out where the newts are breeding and then take action to conserve both aquatic and terrestrial habitats.
ARAG is currently carrying out a series of surveys throughout the region to learn more about the distribution of GCN breeding sites. If you know of any ponds that may contain GCN's, then please inform ARAG.