The Department commissioned Amphibian and Reptile Conservation to analyse and prepare a report on 10 years of citizen science data collected under the Toadwatch survey.
Jersey residents were asked to take part in Toadwatch by reporting sightings of our crapauds (spiny toads) using ponds. Data has now been collected for over 10 years (2005 – 2014) and this analysis has created an up to date toad distribution map for Jersey. It has highlighted features of the Jersey landscape that are most important for toads and suggested areas to create new breeding ponds.
A breakdown of the types of ponds used for toad breeding overwhelmingly supports the suggestion that man-made habitats are critical for the species’ survival in the island. Ensuring that these habitats are maintained and connected across the Island is considered to be a critical task to conserve our toads into the future.
The main document Ten Years of Jersey Toadwatch: Analysis & Recommendations contains much technical information which will allow the modelling approaches described in the report to be repeated in future.
Records of Jersey toads were received from 281 locations between 2005 and 2014 and used to create a distribution map. The same data were used to create a GIS model indicating which features of the Jersey landscape are most important for toads. Ponds and gardens were most important, along with other man-made habitats like parks, golf courses and recreational fields, indicating the reliance of toads on anthropogenic features in the modern Jersey landscape.
Further modelling combined with an analysis of barriers to connectivity between populations (roads) revealed that many toad populations in the centre and north of the Island, especially, are isolated from the larger clusters of breeding ponds found in St. Brelade and St Helier-St Saviour. This can be used to suggest areas where creation of new breeding ponds and other habitat will be most effective as a tool for toad conservation in the Island – specifically:
- Between La Crabière and Les Landes, and between St Ouen’s Village and Grève de Lecq, as well as La Crabière and St Peter’s Village (to link populations in the west of the Island);
- Approximately between Beaumont and Sorel, and along almost any north-south valleys (to link the St Mary – St John population cluster to other populations);
- Eastern Trinity, St. Martin, south-east to Gorey and through Grouville (to restore connectivity in the east of the island);
- Approximately between Beaumont and Bellozane (reconnects the southern population clusters to one-another);
- Between Noirmont, Woodbine Corner and Ouaisné (the latter population not currently recorded as part of Toadwatch) (to connect Noirmont with other populations and improve population robustness in this key area).
Analyses of the Toadwatch monitoring data showed that timing of toad breeding was very variable (starting usually any time between early January and early March) but there was no discernible trend towards earlier breeding. Analysis of any population trends 2005-2014 is difficult due to inconsistencies by recorders; however, the average number of spawn strings per pond was <4, indicating generally small populations. The majority of ponds (81%) also had <30 toads in any one year.
A breakdown of the types of ponds used for toad breeding in Jersey overwhelmingly supports the suggestion that man-made habitats are critical for the species’ survival in the Island. Nevertheless, almost half of the reporters recorded toads being killed on nearby roads – a consequence of their dependence on urban habitats.
Toadwatch has not yet provided much data on other key species (such as grass snakes), though some islanders have begun to record these species. The adoption of an on-line recording system, hosted by Jersey Biodiversity Centre will help improve collection of these data, improve consistency of reporting and allow for more revealing future analyses of e.g. population trends.
Summary of Key Recommendations
- Create new breeding ponds in the areas suggested to improve population resilience
- Continue to support collection of Toadwatch data on-line as a key component of monitoring the species’ status in the island
- Use signage and patrols, where likely effective, to reduce road mortality
- Update the available information on creating toad habitat/ponds.
Download the report Ten Years of Jersey Toadwatch: Analysis & Recommendations here
Jersey Toadwatch has its own Facebook page here