Butterflies in flight home
IN among the worrying headlines about the serious decline in our insect populations, it’s wonderful to be able to bring you a good news story for once.
And this comes in the form of a delicately orangespotted, little brown butterfly.
The Manchester argus (also known as the large heath) butterfly was once a common sight on the peat bogs and mosslands of Greater Manchester, hence its name.
However, the destruction of so many of these precious habitats, often due to drainage for agriculture and peat extraction throughout the 18th and 19th centuries, saw it become locally extinct.
But all was not lost.
A small population of large heath butterflies had managed to hang on at Winmarleigh Moss in Lancashire and plans were hatched to reintroduce the species to its Manchester homeland.
The Manchester argus butterfly is specially adapted to living on boggy peatlands, its caterpillars love nothing more than calling a tussock of hare’s-tail cotton grass home and, once emerged, the main food source of the butterflies is nectar from cross-leaved heath – both species that are found in peatland habitats.
Astley Moss near Astley Green was earmarked as the perfect place. After years of restoration work by dedicated Wildlife Trust staff and volunteers, this now fine example of a lowland raised peat bog would provide the perfect habitat.
So, back in the summer of 2019 six pregnant females were collected from the Winmarleigh population. They were then transported to Chester Zoo, where a special breeding enclosure was awaiting them.
The eggs then overwintered at the zoo, before caterpillars hatched out in March this year.
They then spent the next couple of months feasting on hare’s-tail cotton-grass before pupating. By this time, though, we were well into the coronavirus lockdown and concerns were raised about whether we could complete the release or not.
But thankfully, a socially distant plan was hatched and the pupa were taken from the zoo to a special release enclosure on Astley Moss.
The butterflies started to emerge and could be released onto the peatland – the first Manchester argus butterflies to see their namesake homeland for over 100 years.
The reintroduction of the Manchester argus butterfly will continue, with further releases planned at both Astley Moss and Risley Moss in Warrington next year, with the help of our friends the Warrington Rangers and Natural England.
● To support the work of the Wildlife Trust for Lancashire, Manchester and North Merseyside, text WILD09 with the amount you want to donate to 70070.