Assistant Ecologist Jessica Snow talks about the Great Crested Newt
At Wildwood Ecology conducting protected species surveys is an integral part of our work and this includes assessing the ecological value of a site for great crested newts (GCN). Find out more about this protected species from Jessica Snow, one of our Assistant Ecologists.
Growing up to 17cm, the great crested newt is the largest of three newt species found in the UK. Adults are black or dark brown in colour and with their distinct granular skin are sometimes known as the ‘Warty Newt’. Both sexes have a bright orange underside with irregular black spots, the pattern of which is unique to each individual. During the breeding season the males have a pronounced jagged crest along their back.
Due to their distinct identifying features GCN are easily distinguished in the field from the other two UK newt species, the palmate and the smooth newt. With experience it is also possible to differentiate GCN larva from that of the other species too.
GCN can be found across northern and central Europe, however, their population is in decline and in some parts of Europe they are an endangered species with protection under EU legislation. Within the UK they remain widespread and relatively common in suitable habitat, although often in small numbers.
In England and Wales GCN are predominantly found in lowland habitats. In comparison to smooth and palmate newts their habitat requirements are narrower, with GCN preferring ponds in the mid-size range (about 50-120m2) with good aquatic vegetation and neutral water. The terrestrial habitat surrounding the pond, or other aquatic habitat populated, must be suitable to allow for dispersal and foraging and have appropriate refuge features for hibernation and cover. Semi natural grassland and woodland offer ideal terrestrial habitat, especially when found in a mosaic with a number of ponds. Connectivity between aquatic and terrestrial habitat is essential as GCN often form meta-populations around a pond cluster. As a result of increased human activity and habitat modification, GCN are nowadays often found in artificial or semi-natural aquatic and terrestrial habitats.
Unfortunately, there is a wide range of contributing factors for the decline of the GCN population. Predominantly they have been impacted by the large scale loss of breeding ponds and the decline in the suitability of surrounding habitats. Agricultural intensification and human development have resulted in the destruction of ponds, increased water pollution, fish introduction and habitat succession as a result of neglect. Their terrestrial habitat has faced similar disruption, decline and fragmentation rendering it unsuitable for use by newts.
GCN and their habitats are now protected under British and European law and it is illegal to capture, kill or disturb them during all life stages, or to damage or destroy their breeding sites and resting places. Due to this protection any works that have the potential to impact upon ponds or terrestrial habitat used by GCN could result in unlawful practice so it is important to seek advice if you have any concerns.
Wildwood Ecology can provide you with survey reports to assess the suitability of the site to support GCN and interpret how they may use it and, if required, can advise on mitigation methods to avoid, reduce or manage any negative impacts on the species and habitat.
There are several methods of survey available for GCN depending upon the individual project and the results required including, Habitat Suitability Index, eDNA, bottle trapping, egg search and torch search, netting or pitfall traps and natural refuge search. Surveys can assess the likelihood of GCN presence, confirm the presence or absence of GCN in ponds or on land or calculate a population class size assessment, and the results then used to provide an assessment of the likely scale of impact to individual newts, their populations and habitats.
During my time as an ecologist I have had extensive experience of undertaking GCN surveys including responsibility for carrying out a population class size assessment using bottle trapping, egg search, torch search and netting, as well as conducting habitat suitability assessments and eDNA surveys as part of extended PEA’s. This experience has given me a sound knowledge of newt identification as well as good handling and survey techniques.