RAUK - Archived Forum - Reintroductions

Hi Tony,

This is a subject I give a lot of thought to. As I've mentioned before I am very concerned about genetic isolation both now and in the future.

My view is that any movement should be localised, i.e. if 2 adjacent key adder sites were identified and historically were connected, it might be assumed genetic flow occurred. This might be re-established by translocation and achieve a form of genetic conservation, if some such modern barrier as a major road or housing development has occurred. The key being proof that the populations have become genetically impoverished, and long-term study of the results.

I'm not so sure of the merit of reintroducing adders to a far-flung and isolated site. It seems a little like zoo keeping.

I would rather see habitat enhancement/protection around existing key adder sites (and a lot more effort to identify where these actually are) to allow them to move out and form new populations naturally.

I also have doubts about the viability of reintroductions, evidence that breeding populations have formed seems to be very lacking indeed. The success of Madsen's translocations in Sweden being very much due to the existence of adult snakes at the site, though obviously the aim was genetic conservation as opposed to a reintroduction.

Well, as far as I understand it, this kind of operation has been quite successful as part of the sand lizard species recovery programme, so there may well be some merits to reintroductions, providing the factors that meant animals weren't there in the first place have been addressed. As for the long-distance aspect of the adder translocation. - am I right in thinking there is an estrablished population of introduced sand lizards on one of the Scottish islands?

Whilst I don't know quite what was supposed to be achieved by putting them there, it does demonstrate that long distance translocations can work. I think you should generally go for the nearest possible population though, preferably from captive stock, but this will not always be possible. There is the genetic aspect as well, we know little about the genetic variation of British reptiles across the country, and the importance of this in conservation terms has yet to be assessed. I believe there is research underway at Cardiff University that is looking into the genetic variation of adders and grass snakes across Britain so answers may be forthcoming.

Going through the literature you do find constant references to the fact that reptiles are generally poor at colonising new sites, that isolated populations don't recover from local extinction events, etc. I don't know how much research has been carried out on reintroduction success/failure and colonisation of sites, but I do know of a site created on the edge of a widened road, in the middle of arable farmland, that had a new adder population within a couple of years. Hopefully they're better at getting around than we think!

Phil

The concerns raised above about genetic and population viability issues for reintroductions are well made. I know the background on the adder reintroduction referred to, and it was unfortunately not planned or implemented to the standards English Nature would normally expect. However, it was - as far as I understand - an opportunistic attempt at reintroducing the species to an area which has seen major declines, to a site where the perceived reasons for extinction had been remedied, and it's been started now so our view is to try to get the best out of it. The local herpetologists working on monitoring and management advice are doing a great job.

The main reason for this post is to alert those of you interested in the principles to a recent publication, the JNCC species translocation policy. This gives some excellent background on what to think about when planning reintroductions. You can see it at:

All reintroductions that the statutory agencies are involved in will now have to work to this guidance.

Jim

(Just made the link active Jim)

The JNCC policy relates more to translocations for proactive conservation purposes (e.g. reintroducing sand lizards to counties where they have gone extinct in recent history).  It specifically mentions that translocations undertaken as mitigation for development require further guidelines, but adds that some of the document does provide useful guidance (the principles in Annex 1). It also states that in situ solutions are preferable to translocation. English Nature will be using the document when drawing up new or revised guidance on reptile and great crested newt mitigation.

Jim