Misguided introductions
Posted: Fri Jun 15, 2007 7:57 am
I have heard that Heath Fritillaries have recently been spotted at Over Railway Cutting near Cambridge. The only realistic explanation for this is a that captive bred insects have been released there (as I don't think there is any Cow-wheat anywhere near that and to my knowledge, no such butterflies have ever been seen there before). These butterflies will therefore simply dissappear again.
The issue of artificial releases has been discussed elsewhere on this forum but I would like to flag up the practice again for discussion. Some releases (such as this one) may appear obvious, but others are less so. I believe those who do this genuinely believe that they are helping their chosen species, but it is not something which should be done by any individual without prior discussion with butterfly conservation groups. Anyone collecting data would have their results artificially raised by such activity, leading to a potentially misguided belief that the species is surviving well at the venue. Captive bred insects may hatch at a different time than the original wild versions, and if this is at a time when the food plant in that area is not available, the result is obvious. The practice may artificially increase the number of predators (ie parasitic wasps etc.) and condemn the original population of butterflies to an uncertain future.
Access to live insects via the web is becoming popular and is a great way to see the lifecycle of many species, but in many cases the resulting butterflies should not be released into the wild. It would be good to know if there is any official policy on how one works out which species are OK to release and which ones are not.
PS. It may be that the recent Queen of Spain Fritillary sightings in the UK have been (at least) supplemented with captive releases. How do we know which are genuine migrants and which are simply releases.
Trev
The issue of artificial releases has been discussed elsewhere on this forum but I would like to flag up the practice again for discussion. Some releases (such as this one) may appear obvious, but others are less so. I believe those who do this genuinely believe that they are helping their chosen species, but it is not something which should be done by any individual without prior discussion with butterfly conservation groups. Anyone collecting data would have their results artificially raised by such activity, leading to a potentially misguided belief that the species is surviving well at the venue. Captive bred insects may hatch at a different time than the original wild versions, and if this is at a time when the food plant in that area is not available, the result is obvious. The practice may artificially increase the number of predators (ie parasitic wasps etc.) and condemn the original population of butterflies to an uncertain future.
Access to live insects via the web is becoming popular and is a great way to see the lifecycle of many species, but in many cases the resulting butterflies should not be released into the wild. It would be good to know if there is any official policy on how one works out which species are OK to release and which ones are not.
PS. It may be that the recent Queen of Spain Fritillary sightings in the UK have been (at least) supplemented with captive releases. How do we know which are genuine migrants and which are simply releases.
Trev