Danny wrote:Mark Senior wrote:Greetings to all on here , my first post so may as well make a controversial one .
Many on this thread have argued that it is wrong to release captive bred specimens of species into new or existing areas .
I would argue that it is not only not wrong to do so but that in the 21st century where suitable habitats for many species are so fragmented that it is an essential part of conserving present populations and extending the range of the rarer species to do so .
For example , I know of a perfect site for Duke Of Burgundy's , plenty of food plant , a range of South , East and North facing slopes and no Duke colony within 15 miles . The chance of colonisation by natural forces is to all intents and purposes zero . I would argue that it is would be purely beneficial to introduce captive bred stock onto this site .
Many of our rarer butterfly species now exist in well scattered colonies and unlike in say the 19th century when the range was more continous , these colonies get no new influx into the gene pool from other colonies . This will in the end lead to a weakening of the gene pool and make the colony more susceptible to extinction . The introduction of new genes from release of captive bred specimens can only lead to a stronger gene pool and a more thriving colony .
It is interesting that many who would oppose the release of captive bred specimens into new areas on the grounds of interfering with nature would see nothing wrong in planting for example kidney vetch on a new site in an attempt to attract the Small Blue . Far better IMHO to plant kidney vetch and release captive bred Small Blues .
I should add finally , that I have no connection whatsoever with the breeding of butterflies and have never released any captive bred butterflies into the wild though I would not rule out doing so at some time in the future .
Now everyone can flame away at my post .
I fail to see how crimeful it is to release say: Map/ Scarce Swallowtail/ Queen of Spain/ Large Copper...I mean what's the problem? We get more butterflies to see...is that such a disaster? The Black Veined White for example used to be fairly abundant in the UK before the motor car kicked in. How can repopulating the nation with BVW be so horrid? If a colony took off after twenty years it would simply be indiginous again. I personally agree with the poster. More insects just means more food for the birds, it'd save on feeders and everybody in this group would get rampant about the Cardinal they saw in Derbyshire last week.
Danny
Hi Danny,
I have in past had the same thinking you have, but there are many good reasons to not introduce species never native to the location or introducing more of that species:
First, will the butterfly introduced do well and eat foodplants that say, other native butterflies eat? If so, it could reduce the number of foodplants for local species that have been there and maybe reduce their numbers because of lack of food. The map being one, it feeds on nettles but local butterflies like red admiral, peacock and small tortoiseshell as well as several local moth species feed on nettles, now wouldn’t it be a shame if local butterflies became under threat by someone with your thinking, releasing butterflies like this?
Second, is it the right subspecies? Take the speckled wood it has 3 or 4 subspecies or more, some of which occur in Europe, some occur in different parts of UK. If the subspecies from France and southern Europe was introduced, it could mutate the local subspecies and maybe introduce a disease because of this, or create a new subspecies and drive the current one to extinction in that area.
Third, will the species introduced increase the number of predators such as birds that could feed on it and then go to other species in area? Introducing a species in an area could increase the bird population in that area, they have more food. With this, they could even find local insects and feed on them too, could even make them endangered or go extinct because of the number of predators that now exist because of an introduction of a new species.
Finally adding to the population. Is it wise? You must make sure the adults you have, first, have no disease that can be carried to the population your trying to add too, then it has to be exact same form and subspecies, which cannot always be certain and you have to make sure the livestock you have did not come from another area, thus reducing the population in that area just for your benefit.
People want to protect local species and sometimes introducing new species can do what I said. I am no expert, but there are reasons why you can’t just introduce a species to an area. Probably more than what I said. Some may think its ok, but you have to think long term and think about a few months or a year from now, will the species still be there and what will become of them and local species? Will predators increase? Are they disease free? Are they same subspecies/form etc...? that is in area already? Is there enough foodplants and correct habitat to sustain them?
