Wednesday, August 29, 2012

Suffolk update

Rob Parker, Suffolk recorder has emailed me the following update for publication on the Purple Empire -
I have done a bit of asking around, and can now offer an update for you to post on the Purple Empire:
On 28th July, Matthew Oates wrote: Incidentally, we have received no reports from the introduced population in Suffolk this year. How's it doing? Also, we never receive any reports from Kent, or on the introduced population in Essex. News welcome on these fronts... SUFFOLK UPDATE Since John Quinn made his freelance introductions at Theberton Wood circa 2001-2004, and the population became public knowledge in 2005, iris has continued to fly in that small wood. John agreed not to make any further releases thereafter so that we could be confident that it really was self-sustaining. Happily, they went from strength to strength, and observers watched them 2005-2011, whilst forestry work thinned the conifers, retained most of the sallows and opened rides and canopy somewhat. A number of sightings were also made at RSPB Minsmere (just 3 miles away to the northeast) suggesting that the population was doing very nicely, and in 2011, one male turned up at North Warren, 6 miles to the south east. Enthusiasm continued after John's death, and Theberton Wood is tended by Sam, a forester who is generally to be found amongst the July enthusiasts. It is understood that he was involved in a sallow cutting operation, presumably in 2011, after which a thorough search of the fallen branches discovered iris larvae, and 11 were taken into captivity to overwinter safely. Apparently they survived very well, as Sam was able to release at least 4 in the first week of July 2012, separately, as they emerged, and possibly before the wild population had taken to the wing in a year of extraordinary fluctuations of weather that would probably have delayed emergence of the wild population. It is unfortunate that this release has masked the performance of the truly wild population, but it can be argued that they were Theberton stock that would otherwise have perished. The Emperor was certainly observed at Theberton in 2012, but as usual, valid counts are difficult to obtain, and the County Butterfly Recorder has not received many sighting reports or subjective judgments of population strength. The best, on 26th July, identified 4 separate females (3 with distinctive damage, and one fresh-looking perfect specimen) and one male - a minimum of 5 still flying at that date, and the females engaged in apparent egg-laying behaviour. Can anyone correct or add to this? I do not have a phone or email contact for Sam (or even know his surname). When I visited in July, I had missed him by 20 minutes. I am not in touch with Eileen Quinn either, but I would like to be able to provide Matthew Oates with a more authoritative answer. Sam made no secret that he had taken 11 PE and 5 SWF (presumed chrysalises or maybe caterpillars) into captivity to be overwintered. But I do not know whether he released the same numbers. I think the date of Sam's release was 6th July 2012, but am not certain that this was a one-off event. Rob Parker


Matthew Oates said...

Thanks so much for this Liz and Rob, really appreciated. It's important that we learn from introductions, especially at a relatively small and isolated site like Threberton. Four females on a single day is a useful indicator of a healthy population, and it's good to know that the butterfly can survive thinning operations. I've only visited the site once, in Oct 2009.

Greenwings said...

We'll try and keep you updated more regularly on how things go in 2013. I expect to include the site in our events programme next year, be great if you could join us on that Matthew! Kind regards, Matt (Suffolk Branch).