A brief history of the northern pool frog

The northern pool frog is a genetically distinct group, or clade, of the pool frog species with a limited global range, being found only in very restricted areas of Scandinavia and Estonia.  It has probably always been rare in England, the last population disappearing in the mid-1990s.  Prior to this the northern pool frog was regarded as a non-native species, introduced by humans from elsewhere.  Research, carried out as the last English population declined to extinction, concluded just too late, that this view was incorrect and that the species was, in fact, native.

How this once extinct amphibian was reintroduced to East Anglia

Amphibian and Reptile Conservation (ARC) – and its predecessor The Herpetological Conservation Trust – has been at the forefront of northern pool frog conservation since concerns about the species arose in the 1990s. In collaboration with English Nature (now Natural England), we investigated the northern pool frog and helped to determine its native status. In the early-2000s a decision was taken to attempt reintroduction, in line with the UK Biodiversity Action Plan and the Habitats Directive. We helped develop species action plans, which guided early work, and a reintroduction strategy which was then implemented with help from a range of partners including Anglian Water, Natural England, the Forestry Commission, universities and volunteers. 

In practical terms, this has resulted in reintroductions to two sites in Norfolk. We have been central to these – securing the permissions and funding needed, organising habitat management, undertaking releases and follow-up monitoring. We work with government to ensure that northern pool frog requirements are taken in to account in biodiversity planning and strategies.

First Reintroduction

After gaining permissions from the Swedish authorities, adults and juvenile frogs, and tadpoles and spawn were collected from Sweden from 2005 to 2008.  The animals were screened for health conditions, before being brought to the UK and released at an undisclosed Norfolk nature reserve where a breeding population has become established.

Thompson Common by Helen Maxwell

Second Reintroduction – Thompson Common, Norfolk

In 2015 northern pool frogs were released at a second site in Norfolk, Thompson Common. This was the last known location where these frogs occurred in England before becoming extinct. For this reintroduction, frogs were transferred from the first reintroduction site using a technique called head-starting.  In this case we have taken spawn and reared tadpoles in captivity to provide stock to release into the wild.  Head-starting took place in four stages, in 2015, 2016, 2019 and 2021. You can read more about the project in our leaflet 'Re-introducing the northern pool frog to NWT Thompson Common,Norfolk'

Continuing work

In 2021 ARC received funding from the government’s Green Recovery Challenge Fund.  This gave a significant boost to northern pool frog recovery, which we continue today.

New Sites for Northern Pool Frogs

To ensure the long-term survival of the northern pool frog in England we are looking for further sites to reintroduce the species. A site specification is available as a PDF or a brief video.  We welcome discussion with managers and/or owners of potential reintroduction sites. Please contact John Baker or [email protected].

Partners and Funders

Work to recover the northern pool frog is the long-term effort of partnership-working.  Our partners include independent herpetologists and:

Anglian Water Find out more about the biodiversity work carried out by, or with, support from Anglian Water.

Norfolk Wildlife Trust Find out more about the species and habitats at Thompson Common. 

Forestry England is a long-term partner in northern pool frog recovery.

University of Brighton

University of Kent, DICE

Zoological Society of London

We are especially grateful for the long-term financial and in-kind contributions from Anglian Water and Natural England, which have been instrumental in turning around the fortunes of the pool frog. Other funders have also generously supported our northern pool frog work at various points, including Heritage Lottery Fund via the Breaking New Ground project and the Green Recovery Challenge Fund.

ARC is also grateful to the following organisations, whose support enabled the establishment and equipping of our head-starting facility in 2019: Amphibian Ark; Anglian Water Flourishing Environment Fund, a charitable fund managed by Cambridgeshire Community Foundation; British Herpetological Society; Keith Ewart Charitable Trust; Natural England.  We also thank all the individuals who have donated money via our sponsor the pool frog appeal. We are continuing to fundraise to support the operation of the head-starting facility in future years.

If you would like to support this work please visit our Sponsor the pool frog page.