Introductions

[Nigel]

Neil Jones wrote:

>The conservation of species is my main concern.
> This practice of carrying out introductions is causing problems with
> other species. Particularly the Marsh Fritillary. It has been well
established
> with this species that introductions DO NOT WORK WELL. Yet misguided
people
> persist in releasing them. This produces temporary colonies which makes
> the butterfly seem more common, diverts conservation effort etc.

I wrote my last mail before I saw Neil's reply, so just to conclude:

Conservation effort is fairly meaningless when one of the largest known
colony of Marsh Frits in England now resides underneath a huge housing
estate near Chandlers Ford Hampshire. 

It's difficult to tell the status of Marsh Frit colonies, as an annual
count means nothing. This species has cyclic dramatic decline followed by
explosive increases in numbers (See) E.B.Fords monitoring of a single site
over many years, importantly the site monitored was unaffected by human
activity so is a good bench mark for the species. I'm pleased to see that
this species has full protection in UK now, except probably from
earth-moving equipment and house builders.

However conservation is a double edged sword.... altering a site to become
suitable for one species may send another into decline! So if the site
looks suitable, and it won't interfere with current local conservation
activities (and it's legal) then release some as an experiment before you
start altering habitat. You can at least determine that the site remains
unsuitable if nothing happens, and that gives you a bench mark to work on.
Nigel