In the Field

By hook or by Crook(sbury)

By Ralph Connolly - Weald Field Officer & Volunteer Coordinator

If you came to the virtual Friends’ Day this year, you will have seen footage of the natterjack toad ponds on ARC’s Crooksbury Common site and the quite specific open habitat requirements of this endangered species.

The natterjack population on Crooksbury is small and doesn’t breed every year but last year we were delighted to record three distinct spawning events.

Unfortunately as our climate changes, the increasingly long drought periods we are experiencing can have drastic consequences for natterjacks. Many of the shallow, warm pools that they favour for spawning are drying out too quickly to enable them to complete their metamorphosis from tadpole to toadlet.

All three spawnings on Crooksbury required intervention by licensed ARC staff to top up the water levels or translocate the tadpoles to one of the larger ponds onsite and in one case the tadpoles were lost.

To counteract this, the three smallest saucer-shaped ponds have been skilfully re-profiled by one of our contractors with a small excavator. This will increase their capacity whilst retaining the gentle sloping sides which maximise the amount of shallow warm water for natterjacks to develop quickly in.

We have also fitted the ponds with liners to further improve their water retention and were generously supported in this by funding from the Surrey Amphibian and Reptile Group.

Monitoring of the ponds by ARC staff and volunteers will continue over the coming years and hopefully we will be seeing natterjack toadlets scrambling out next summer!

Game Changer

By Jim Foster - Conservation Director

Pheasant © Chris Dresh (ARC)

‘Government’s about-turn on pheasant release licensing is a promising development, though concerns over reptile impacts remain,’ says ARC’s Conservation Director, Jim Foster.

These extracts, taken from Jim’s blog, make for some interesting and thought provoking reading. You can read the blog in full on our website at www.arc-trust.org/

news/game-changer

On 30th October, Defra announced that from 2021 releases of pheasants and red-legged partridges on or close to European protected sites in England will need to be licensed. This about-turn by government is a response to a legal challenge by Wild Justice. Indeed, there has been a flurry of news on gamebirds recently. August saw the publication of a “rapid evidence assessment” of the ecological consequences of gamebird releasing, commissioned and jointly funded by Natural England and the British Association of Shooting and Conservation. RSPB published a significantly updated review and refreshed its position on gamebird shooting in October. A peer-reviewed paper assessing the evidence for effects of pheasant and red-legged partridge releases on wildlife was also published in October. That’s a lot to digest, and I’ll just comment on some specific reptile issues, without attempting to cover the broader nature conservation and socioeconomic issues, crucial though they are. The notion that reptiles might be harmed by some gamebird releases has long been a concern for ARC and its predecessor The Herpetological Conservation Trust. This concern has been generated by our own observations, and through liaison with volunteers, scientists and other land managers. Most discussion on the topic centres on pheasants as predators of reptiles. After all, some birds are known to take large numbers of reptile prey – as an extreme example, in New Zealand the government is deploying chickens (incidentally, in the same Order as pheasants) to eradicate introduced reptiles. Pheasants certainly do eat British reptiles. But then, so do plenty of other animals; the crucial point is to determine whether this additional predation pressure has a populationlevel effect on reptiles, either alone or when interacting with other factors. Moreover, it’s plausible that indirect effects might be equally or even more important than direct predation. These include the effects on invertebrates, vegetation, and the local abundance of generalist predators. The release of such a large biomass of birds surely has some impacts on ecosystems, of which reptiles are one component. Alongside this, of course, are the potential positive effects of gamebird management on reptiles –primarily the creation and maintenance of hedgerows and other habitat features. Assessing the net impact of potential positive and negative effects is complex, as acknowledged in the papers cited above, especially in relation to the spatial extent over which impacts occur. In addition, any impacts on reptiles are likely to depend on a range of factors, such as the number of birds released, the location of release pens in relation to reptile distribution, and the quality of habitat for reptiles in the vicinity. There needs to be a rethink about how to ensure gamebird releases don’t unduly impact on reptiles across the UK generally. Not all gamebird releases have potential for adverse impacts on reptiles, but existing mechanisms don’t appear to be effective for assessing - and if necessary modifying or preventing - those that do. Further research is warranted, and ARC has plans for how this could best be conducted, with a focus on assessing population-level effects. The more evidence we have, the better we can target mitigation and restriction. But that research would take substantial resources and several years to conclude. In the meantime I think we need a more urgent look at the practicalities of reducing the potential harms and optimising the benefits of gamebird management as far as reptiles are concerned. The fact that we now have published concordance among key stakeholders about the risks to Britain’s snakes and lizards means this is tantalisingly feasible.