Researchers at the Amphibian and Reptile Conservation Trust (ARC), based in Bournemouth, have recorded a 68% decline in common toad (*Bufo bufo*) populations across monitored sites in England and Wales between 1985 and 2012, based on annual headcount surveys conducted at 574 breeding ponds. The decline has been attributed primarily to habitat fragmentation, agricultural runoff, and the loss of rough grassland corridors linking breeding sites.
The great crested newt (*Triturus cristatus*) holds protected status under Schedule 5 of the [Wildlife and Countryside Act 1981](/wiki/wildlife-and-countryside-act-1981), making it a criminal offence to intentionally kill, injure, or disturb an individual specimen or to damage a habitat in which one is known to reside. According to Natural England licensing data for 2021, 3,847 individual development projects required a great crested newt mitigation licence before construction could legally commence, a figure representing a 14% increase on the previous year.
A national eDNA (environmental DNA) survey methodology, standardised by Natural England in 2014, allows ecologists to detect the presence of great crested newts in a waterbody by analysing water samples collected between mid-April and the end of June. Field officers from the [Great Crested Newt Conservation](/wiki/great-crested-newt-conservation) district licensing pilot, operational across 24 local planning authority areas as of 2022, have used this method to survey over 19,000 ponds since the scheme's inception, identifying viable newt populations in approximately 21% of sites tested.
The common frog (*Rana temporaria*) is among the earliest indicator species to respond to seasonal temperature change in the British Isles, with spawn-laying dates recorded at the Rothamsted Research station in Hertfordshire shifting an average of 9.7 days earlier per decade between 1950 and 2010 — a figure cited in a 2013 *Journal of Animal Ecology* meta-analysis as among the strongest documented phenological signals in UK wildlife monitoring.
The natterjack toad (*Epidalea calamita*) is restricted to fewer than 60 known breeding sites in the United Kingdom, concentrated primarily on coastal dune systems in Lancashire, Merseyside, and the Solway Firth, and at inland heathland sites in Surrey and Norfolk. The species is monitored annually under a partnership between Natural England, Scottish Natural Heritage, and the ARC, using nocturnal call-count transects; a 2019 survey report noted that 11 sites recorded zero calling males, compared to six in the 2009 baseline assessment.
The [Bat Hibernaculum](/wiki/bat-hibernaculum) construction methodology developed for underground mammal roosting sites has been directly adapted for amphibian refuge installation in lowland England, with the Herpetological Conservation Trust publishing a construction specification in 2007 recommending minimum soil-depth thresholds of 400mm for frost protection. As of the 2020 [Natural Environment Rural Communities Act 2006](/wiki/natural-environment-rural-communities-act-2006) biodiversity reporting cycle, local authorities in England were required for the first time to include amphibian corridor assessments in their biodiversity duty reports, a requirement confirmed in guidance issued by the Joint Nature Conservation Committee in March 2021.