Ethics of reintroducing locally extinct moths to a small area of land to figure out their decline

In late January I’m expecting a delivery of some Kentish glory pupae for me to try to breed and raise but the the thought dawned on me about potentially releasing some caterpillars in a nearby wooded area ( not a reserve just an area with a lot of birch trees) to try and figure out if they’d survive for a couple years. This species was formerly native and quite common in Warwickshire but the last recorded sighting nearby ( in Worcestershire) was nearly 60 years ago and they’re now confined to areas of Scotland. Their decline has been linked to deforestation and climate change and I was hoping to try and see if the population would last a few generations. I’m not doing it out of expectation for them to start recolonizing their entire former range and don’t doubt that they’ll eventually die out from inbreeding or other factors but just want to try it out. They’re not destructive in feeding habits, have no risk of messing with the gene pool of highland glories since they aren’t long distance flyers, are completely non toxic for any local wildlife and are overall a real Country gem. I know this is a controversial topic but want to weigh in on opinions from multiple people. I have other release projects but they’re all still present in my area but are just scarce.


This sounds like a good initiative! I would suggest to get in touch with the Warwickshire Wildlife Trust, Butterfly Conservation or the relevant regional agency for biodiversity, to get some feedback and also so that your efforts are known about (if, for example, people start recording the species in the area and think it’s a natural recolonisation). There are various issues with reintroductions that have to be carefully analysed (disease risk, genetics of source population, understanding of the reasons for the original disappearance and whether those factors have been ameliorated), and for this reason, it’s always a good idea to involve others in the decisions and planning. The IUCN has produced guidelines for reintroductions, which should be followed in this sort of project. Good luck!


I generally discourage attempts to reintroduce species to areas without checking first with relevant authorities. Transporting and releasing individuals intentionally carries many risks which aren’t immediately obvious/understood, and in some places will definitely be illegal.


yeah I’m not hedging on success, It’s just a curiosity of mine. If possible I would just have a big net with some birch inside but people would mess with it. As for taxonomic mixing it’s something which I admit is annoying, there are many cases of similar species being reclassified as two separate ones ( like clouded yellows, wood whites and others) which is sometimes only found after many generations of interbreeding in areas which they’d normally be isolated from. Then again I’m not going to act like even large organizations are innocent of this like in this case where they added Belgian chequered skippers to a Northampton forest where they’ve been absent for 40 years. I’m quite familiar with the well known ( and now deceased) Martin White and his many reintroductions of various extinct and scarce species to various areas. Although I’m not big in the butterfly scene this appears to be a very big controversy amongst people for the reasons you’ve stated. I generally don’t have qualms against his works but I do note that it’s definitely messed with many recorders and entomologists. As a side note, silkmoths ( specifically Samia cynthia and the spanish moon moth) have actually caused quite a conundrum in Italy due to introductions for silk farming though that’s a topic for another time.


This is how I feel too.

1 Like

Should curators have a critical point of view when changing iNat taxonomy? - Curators - iNaturalist Community Forum

1 Like

I dislike introductions / re-introductions / re-inforcements, whether done by ‘officials’ or well-meaning amateurs. I like wildlife to be wild. If someone put it there, it isn’t wild. British conservation is becoming like a series of theme parks with introduced water voles, beavers, pine martens, red squirrels, dormice, sea eagles, cirl buntings, storks, pool frogs, sand lizards, natterjack toads, raft spiders, soldierflies, and too many Lepidoptera to keep track of. Then there are the flower scatterers. There would be much greater benefit to wildlife if the money and effort was put into acquiring habitat and looking after it. But introductions are loved by politicians (quick results, good photo opportunities, don’t get in the way of industrial developments) and the conservation bodies are led by the money.

On the other hand, when you see an orangutan being coaxed out of the trees before its patch of forest is felled, it is hard to argue it shouldn’t be moved somewhere safer.

In this specific case, where are your Kentish Glories coming from? And what aspects of their ecology are you planning to monitor in order to learn why they fail or succeed?


Origin wise I’m in the process of contacting the seller but from the fact that another seller is dully selling them as " European stock" I’d assume that they’re several generations captive bred with original stock being from Austria, Belgium or similar ( I got them from an Ebay seller). As for monitoring ecology I mainly want to test if the warmer temps make them emerge earlier than the time that the first birch leaves appear and if they’ll settle with older birch and alder trees as opposed to young growth.

I would not trust any seller from the internet to be sure of (or honest in regards to) the origin of specimens they are dealing. If captive bred, specimens can easily have picked up diseases/parasites in captivity which are essentially undetectable that they can transfer to native populations.

For research I have done, we often aren’t allowed to re-release captured specimens if we have held them in captivity at all. Though I don’t always think this is necessary, I understand why these rules are in place - a disease outbreak in native populations, even if rare, is likely to have a much stronger negative effect than any positive effect of rereleasing or introducing a small number of individuals.


Knowing that my research is sentencing them to death would cause me to rethink even doing the research at all. “It matters to this one.”


I want to live in this fictional place with billions of dollars for entomology research! :upside_down_face:


There is a video of a presentation on how the large blue butterfly went extinct and how it was successfully re-introduced. Researchers understanding its host’s lifecycle was critical. Might help serve as a model

But I am sure there are probably laws against rewilding without permission.


I’m sure that’s happened before with at least 3 or 4 lepidoptera in the UK due to similar reintroductions. Usually successful colonies will do well for 4-5 years before crashing.

Appreciate the link, I’ll be sure to take a peek soon. As for rewilding laws, from what I remember from head is that releasing native species is legal although I really need to study these laws better as there’s surely more to it than that. Most of the UK butterfly laws that I know are mainly about collecting and trading wild caught specimens.

1 Like

This has happened. A Peterborough butterfly rearer in the 80s was releasing Duke of Burgundy Fritillaries into a young conifer plantation. Meanwhile a butterfly ecologist working on D of B conservation couldn’t understand why this colony appeared to be thriving despite the growing trees making the habitat unsuitable. I don’t think he was bald though. Or a billionaire.


As well informed as you seem to be, I am guessing that if you have to ask on a common page about the potential drawbacks to your idea, then probably you are not an expert. And it also seems that humans have a predilection for screwing things up even with small actions that we figure won’t make a difference. And it sounds like the benefit of it is only to satisfy your own curiosity - but it probably isn’t going to be well-controlled enough to constitute real research and probably not going to help the greater community understand this species any better. I’d avoid it…
Maybe see if you can get involved with local universities to see what research you could help with, or keep an eye out for opportunities on here. Are your other release projects part of a coordinated effort? We’ve been finding in the States that releases of captive organisms sometimes are harming certain populations - I’m hesitant to do anything on my own. I know science isn’t perfect but at least running ideas by several minds that have been well-informed on the topic can help avoid most mistakes.


I have been watching 2 koi fish (unwanted pets) set free in the Otter Pond in Kirstenbosch. If I look at the iNat map for Cape Town … I am horrified to see them across the city.

But. It is just. One, or two, unwanted pets …


I’m by no means an expert ( nor do I claim to be), just someone who records and raises lepidoptera as a hobby. As for my other projects they’re solely being done by me and it’s currently releasing garden tiger moths, privet hawkmoths, buff tips and lime hawkmoths as of now ( that’s what I was advised by the sellers and am also doing it since they’re all UK collected stock and are present but somewhat scarce in my area). I realistically don’t have enough livestock to maintain a genetically strong population for any amount of time so more than likely I’ll trial the whole thing for a year or two in a large net enclosure inside my garden with some Birch ( and see if I can buy any other bloodlines) so for now it’s just a theoretical. If I notice that there aren’t any issues with development or similar relating to the species then I’ll likely enquire to bigger organizations and groups and take it from there.

Koi and goldfish do have a tendency to be dumped in the most random places by either lazy and negligent individuals who don’t want to look after them anymore or by " activists" that think that they’re releasing them into their “natural habitat” to free them from the prison of captivity. There was a power plant in the UK with a nearby water body that was filled with dumped exotic aquarium fish for a while until It eventually shut down, In all fairness I wish I could have been there to actually record the species there since I can hardly find any info about it.

@mothdragon After having asked and gotten these replies, what are your thoughts now on your project?