www.ukbutterflies.co.uk

I have an interesting question that perhaps someone who knows more about conservation practices than I do might be able to help me with. It is perhaps best illustrated by using a specific species.

The Spurge Hawk-moth (Hyles euphorbiae) is currently a relatively scarce occasional immigrant into the central southern counties of England. Back in the 1800s it was resident and used to happily breed here but no longer does. It used various wild spurge species as its larval foodplant, Euphorbia helioscopia for example, which still grows here in the wild.

My question is would the Spurge Hawk-moth be a species that conservationists actively seek to encourage to breed in this country once again? If not, is it because there is no ecological advantage, that it stopped breeding here such a long time ago, that it is not endangered elsewhere, the financial cost of bringing it back or some other reason, perhaps it would be considered invasive in some way? In other words, what are the criteria used in deciding whether or not to conserve a particular species?

Sorry to ask so many questions but it is something that puzzles me. There is no doubt that to have such an incredible insect breeding in Britain again would be amazing - but is that enough of a reason I wonder?

Thanks for any help in advance.

Cheers,
Phil.

Well that's a hot potato opening a can of worms isn't it!

Here's the official line:

https://butterfly-conservation.org/site ... s-2010.pdf

Oh, thanks for that bugboy, I wondered if there was an official policy.

Give me a day or so to take it all in and I will post my personal thoughts on the content of the document.

It wasn't meant to open a can of worms, just me trying to understand the whys and wherefores of things .

Cheers,
Phil.

OK, I've now assimilated the text to the best of my ability, it is necessarily a bit legalistic in places and I don't pretend to be a lawyer or understand some of the nuances involved but I get the gist of it. In the main I agree with most things mentioned and I'm really glad that such a document exists for us all to be guided by.

On a global basis though, my feeling is there is too much mid level 'conservation' going on, because it is an 'in thing' to do. If any given species is critically endangered or threatened then it is absolutely right that conservation organisations take the action needed to intervene before that species becomes extinct. Especially if mankind was the reason for the decline through deforestation for example, or changing a habitat to make way for farming. However, with my limited knowledge, I currently believe that nature will find its own way in the majority of cases, the distribution of a species will increase and decrease as suits the animal concerned and we shouldn't interfere with that.

Rather than release a species into the wild in order to re-introduce it, I prefer to see conservationists maintain habitats and let the animals re-establish themselves if they wish to do so. We cannot get into the minds of other species and shouldn't presume that we can, we tend to look at things only from our understanding of life, not theirs. Let nature decide and run it's own course.

So, do I think Hyles euphorbiae should be re-introduced to breed in Britain again? No I don't, unless conditions change naturally and they decide to breed here again. And if they do, naturally, I'll be one of the first to jump with joy.

I may be being a bit naive but, with my limited understanding of conservation, that is how I'm thinking at the moment.

Differing opinions are great because that is how we all learn so if anyone wishes to comment please do go ahead, it'll all help.

Cheers,
Phil.

Spurge and Bedstraw Hawks along with others in that group of European Spingids, are surface pupating species, like the Elephant Hawk, and although they breed here in Summer, it is very doubtful they can survive our winters at present. Hummingbird Hawks have taken to hibernate as adult moths rather than a pupa that is about 15 days old when the moth hatches.

My knowledge of this subject is relatively shallow, but I can see there would be a difference in how you would approach species that are naturally mobile and those that are sedentary. Maintaining, extending and/or recreating habitats is a good way of encouraging mobile species to increase their range or reoccupy former territory, but there is little point with a species that is simply unable to reach an area of new habitat however ideal it might be.

It is in this latter situation that deliberate reintroduction can perhaps be justified - hence the project to reintroduce the Chequered Skipper in the East Midlands for example. Creation of habitat "corridors" can help the (albeit slow) spread of relatively sedentary species, but if a completely isolated pool of such a species dries up, then deliberate reintroduction will likely be the only way to bring it back.

On a slightly different (but related) topic, there is the subject of introducing species to areas where they have never previously been found. With the reality of climate change, species will respond if they can by moving to adjacent habitat that may have become suitable for them as their former homes become more hostile. The problem occurs when there is an insurmountable barrier of some sort - either man-made land redevelopment for example, or a natural obstacle such as a mountain range or a stretch of water. The English Channel is a good example of the latter.

The question then arises: if a species is being squeezed northwards and starts to run out of options because the Channel is in the way, yet suitable habitat and conditions are becoming available on the other side, is it "right" (whatever your definition of this is) to introduce the species here? Does it make a difference if it once did occur here or is completely new?

I can't answer these questions! Coward that I am, I am happy just to ask them without expressing an opinion either way. However, others may wish to do so...

Cheers,

Dave

I live a mile west of Oaken Wood in Surrey, and here there are strenuous efforts to extend the range of the Wood White, and it might be working. Also in Surrey there is an attempt to re-introduce the beaver. Now we all know that the last beaver was turned into a tippet or a fur hat centuries ago and so any introduced animal will be genetically different. It is claimed that these animals will do beaver things and improve the environment for life that likes soggy woodland. No consideration is given to beasties that have filled the intervening void - let them drown.
I hold the same view about lepidoptera. Improve the environment, maybe nudge some up the M1 but don't go and fetch a new species from Calais simply because someone thinks the last one reached here in 1066.
Having Oaken Wood as its only residence, is the Betony Case bearer Coleophora wockeella. Amongst all the vetches being planted for the Wood White I hear no mention of Betony plugs going in. A case of racial discrimination? Micro moths are small and boring but butterflies will attract attention.
I am biased and grumpy having just spent another afternoon on creaking knees examining the virgin leaves of my Betony plants.