Keystone Ecology were commissioned to carry out Great Crested Newt and terrestrial invertebrate surveys of a proposed 24km alignment for a new motorway across the Gwent Levels. For Great Crested Newts we undertook Habitat Suitability Index assessments of 153 waterbodies, reens and ditches within 500m of the proposed route, followed by 4-day presence/absence surveys and 6-day population size class assessments where Great Crested Newts were found. The work was carried out during the optimal survey season at 1 week’s notice using a team of 14 surveyors working under Countryside Council for Wales Great Crested Newt survey/handling licenses. For invertebrates we carried out habitat suitability assessments of the proposed route, followed by three detailed invertebrate surveys of those sites identified as warranting further surveys. Five survey methods were combined to gain an indication of the invertebrate species present and their distribution: sweep netting; direct searching; beating of vegetation; pit trapping; and window trapping. The latter two methods involved the setting and checking of around 400 traps.