THE AGILE FROG Species Action Plan Rana Dalmatina SUMMARSUMMARSUMMARYYY DOCUMENT
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THE AGILE FROG Species Action Plan Rana dalmatina SUMMARSUMMARSUMMARYYY DOCUMENT The agile frog Rana dalmatina is Despite the efforts of these distributed widely throughout much of organisations, the future of Jersey’s southern and central Europe, but is agile frog is still far from secure. The found in only a few northern locations factors which probably played a key including Jersey - the frog is not found role in the frogs decline are still very anywhere else in the British Isles. The much in evidence: Jersey population of the agile frog has been declining in both range and •water quality and quantity, as a result SSSpppecial pointsss ofofof numbers since the early 1900’s. In the of intensive agriculture, are still below inininteresteresteresttt::: 1970’s only seven localities were listed EU standards in many areas; The agile frog is protected where the frog could still be found, and •the continuing alteration, disturbance, under schedule 1 of the by the mid 1980’s this had fallen to and loss of potentially suitable Conservation of Wildlife only two sites. In 1987 one of the amphibian habitat; (Jersey) Law 2000. remaining two populations was lost as a •the growing numbers of predatory result of a lethal spill of agricultural ducks, cats, and feral ferrets. DESCRIPTION pesticide into the breeding pond. The The agile frog Rana dalmatina species is now believed to be confined These and other factors have combined is a European brown frog, to a single vulnerable population in the to reduce the frog population to the growing up to 90 mm (snout south-west of the island. to vent). The hind limbs are critical state at which it exists today. long (the heel extends beyond The Agile Frog Group (AFG) was the snout tip in adults). The In the face of intensifying threats, the snout is rather pointed, the ear formed in 1993, when the catastrophic need for a concerted, co-ordinated drum large and close to the decline of the frog came to light. Its conservation effort has become acute. eye. members include staff from the This need has prompted the production Environmental Services Unit of the of the Agile Frog, Species Action Plan. HABITAT States of Jersey Planning and This Action Plan documents the The agile frog’s European Environment Committee (ESU), the historical decline of the species; habitat comprises of Herpetology Department of the Durrell identifies the current major threats to its woodlands and wet meadows Wildlife Conservation Trust (Durrell survival; summarises the current action and, unlike the common frog Wildlife), the Zoology Section of the Rana temporaria, it is rarely being undertaken to conserve the Société Jersiaise, and other concerned found in fields or gardens. species and, most importantly, seeks to local naturalists. Through captive- define the action required in the future LOCAL DISTRIBUTION breeding, reintroduction of the frogs to to return the species to ‘Favourable The agile frog’s distribution in the wild and careful management of Conservation Status’ as defined Jersey has declined from their remaining habitat, the Group has overleaf. seven localities in the 1970’s been trying to stop the decline of agile to a single site in 2000. frog numbers. Conservation efforts have tried to increase this distribution to a further two sites in the island. Page 1 Species Action Plan AAACCCTTTIIION PLON PLAN OAN OBBBJECTIJECTIJECTIVVVESESES CURRENT STTTAAATTTUSUSUS ANANANDDD TTTAAARRRGGGETETETSSS The overall aim of the Action Plan is to provide a In the wild - The agile frog in Jersey is now confined to framework of achievable, practical objectives which, only a single site, L’Ouaisné Common. In less than 30 when implemented, will restore the agile frog to years their distribution has declined from seven sites in Favourable Conservation Status as defined in the the west of the island to this single location. Work has European Union Habitats and Species Directive (1992), started on introducing/reintroducing the frog to other by the year 2005. sites in the wild, but it is still too early to judge whether this will be successful. In ‘captivity’ - The primary aim of the captive Favourable Conservation Status’ exists when: Data on populations is to maintain a self-sustaining ‘safety net’ the population dynamics of a species indicate that it is in the event of the extinction of the species from the maintaining itself on a long term basis as a viable wild. Their secondary purpose is to generate surplus component of its natural habitats, and the natural range tadpoles and frogs for reintroduction into existing, and of the species is not being reduced, and is not likely to be reduced for the foreseeable future, and there is, and potential, new sites. To this end, there are 6 captive/ will probably continue to be, a sufficiently large semi-captive populations in outdoor enclosures around habitat to maintain its population on a long term basis. the island, with an estimated total population of 50 adult animals. Action Plan Objectives CURRENT FACTORS 1. To ensure that there is protection of, and a conservation CAUSING LOSS OR DECLINE management programme for, all existing natural sites, introduction sites or re-introduction sites. Habitat loss/fragmentation - through development for TARGET: To achieve site protection for all sites housing etc. small-scale by 2002. turnover of semi-natural 2. To increase the number of habitats to agricultural land. populations and widen the Water quality - Pollution of animal’s distribution through groundwater from agricultural introductions/re-introductions. chemicals and domestic TARGET: Maintain waste. a sustainable, Pollution events - In 2000 breeding population alone the Water Resources at two new sites Unit of the States of Jersey (Noirmont and one other to be identified) responded to over 167 by 2005. incidents of pollution. 3. To maintain a viable captive population of frogs with a Water shortages - The loss of ephemeral ponds as a minimum of 20 adult animals at a minimum of three locations result of a lowering of the water table, through (a minimum of 60 adults in total), abstraction for domestic and agricultural use. TARGET: Continue captive-breeding programme Predation pressures - Frog spawn is eaten by ducks and at least until objectives 1&2 (above) are satisfied. palmate newts. Adult frogs are eaten by birds, cats and feral-ferrets. 4 To further investigate the threats to, and applied ecology of Introduced exotics - Common frogs Rana temporaria this species in Jersey. and mainland European green frogs Rana lessonae/ TARGET: Maintain funding for PhD study on the esculenta, are already becoming established in Jersey agile frog in Jersey until 2003. and will compete with, and predate on, agile frogs. 5. To raise the profile and level of awareness, of the agile Small population effects - due to the current population frog’s plight in Jersey. ‘bottleneck’, future generations of frogs may become TARGET: Raise funds and embark on an active exposed to so-called ‘genetic risk factors’, such as publicity campaign in early 2001. inbreeding depression. The recovery programme has developed steadily over The action required to achieve these targets/objectives is out the past decade, and now incorporates a lined on page 4. Page 2 Species Action Plan CURRENT ACTION of the life-cycle, it is intended to Legal protection Site safeguards increase recruitment to the wild • The agile frog is now protected under population. ‘Stop feeding the ducks’ schedule 1 of the Conservation of campaign to make people Wildlife (Jersey) Law 2000. The law aware of the negative affect Protection of wild spawn - Wild spawn feral ducks have on local protects the adult frog, tadpoles and is, in the main, kept in situ, but native wildlife. spawn from any interference. The law protected from newt and duck predation • Investigate the potential to also forbids the release of non-native using plastic mesh baskets or willow locate duck deterrents at, species in the Island. This law requires “corrals”. ‘at risk’ sites. proper enforcement, and its existence should be publicised further. Monitoring of wild and release sites The amount of spawn is monitored number of facets. annually, and night sorties made to sites during the breeding season in an attempt Captive/semi-captive breeding - to count reproductively active adults. Captive breeding takes place at a number of outdoor compounds around Monitoring of water quality – This has • the island, with the intention of provided clear evidence of the A campaign to make people maintaining a self sustaining captive potentially harmful levels of certain aware of the dangers of pet and feral cats, and to work ‘safety net’ and to generate surplus chemicals that are appearing in Jersey’s with local groups who care tadpoles and frogs for reintroduction. water bodies. for and seek to sterilise the local feral cat population. Creation of a new ‘wild’ site – For the Habitat protection – Seek to facilitate • Noirmont pond is the most past 4 years, captive bred tadpoles and urgent designation of SSI status to important site for a frogs have been released into a new, important conservation areas, and to reintroduction programme. encourage other designations to protect The water quality needs to small, isolated sites, by lobbying the be monitored, and the Planning and Environment Committee. group should seek to work with Public Services Habitat Management – Techniques such Department and as the coppicing of willow and the Agriculture and Fisheries department, who presently deepening and enlargement of dune administer the land, to slacks at L’Ouaisne have aimed to ensure that the surrounding provide more suitable conditions for the land does not return to survival of the agile frog at this site. agricultural use. Management plans for both L’Ouaisne • Signs and where necessary and Les Landes are presently being fences and gates to protect drafted.