Analysis of the long-term effects of abiotic factors on Jersey’s Agile Frog (R. dalmatina) population

Rana dalmatina has an extensive range spanning Europe and Northern Turkey (Ward et al.,
2016). However, throughout the British Isles, R. dalmatina is only found on Jersey, accounting
for one of the three native amphibian species, along with Bufo spinosus and Lissotrition
helveticus (Ward and Wilkinson, 2019; Ward et al., 2016). The species is protected under the
Conservation of Wildlife (Jersey) Law 2000, after population declines were noted throughout
the 1900s, with the population restricted to one site, Ouaisne common, by 1988, making the
species critically endangered within Jersey (Ward and Wilkinson, 2019; Ward et al., 2016). In
1987, a herbicide (atrazine) spill extirpated the Noirmont population, prompting collaborative
intervention between the Government of Jersey, the Durrell Wildlife Conservation Trust
(DWCT), the Société Jersiaise, and the Jersey Amphibian and Reptile Group (Ward et al.,
2016). In-situ interventions involved water quality restoration, slack improvement, and habitat
management, including removing invasive freshwater plants (Ward et al., 2016). The Noirmont
population was reintroduced in 2000, and a Species Action Plan has been running since 2001,
with captive husbandry and head-starting of R. dalmatina at DWTC recognised by the IUCN
for re-releasing over 48,000 head-started froglets between 1987-2014 (Ward et al., 2016; Ward
and Griffiths, 2015). The two surviving breeding sites, Ouaisne and Noirmont, have been
ecological Sites of Special Interest since 2007 (Ward et al., 2016).