Dozens of large heath butterflies, carefully bred at the zoo, are returning to the North West of England – where they have been missing for 150 years.
Large heath butterflies, once commonly found across the region, disappeared from Greater Manchester over a century ago following the destruction of their habitat for agricultural land, leaving just a few small isolated populations in other parts of the country.
Experts at The Lancashire Wildlife Trust collected six more wild female butterflies from a surviving population and transported them to us.
A team of four specialist invertebrate keepers then spent a year caring for and breeding the butterflies; creating bespoke enclosures for egg laying, rearing the caterpillars and then finally the pupation stage, all in a special behind-the-scenes breeding facility.
Under the watchful eye of our team, 45 pupae are now being transported in stages to their new home in a secret location in the peatlands of Greater Manchester. Here, they undergo their magical transformation and emerge from their pupae as large heath butterflies in protected tents – before being reintroduced into the wild.
Heather Prince, part of our invertebrate team, said:
“Breeding and rearing butterflies in an incredibly delicate process that requires a fine balance of conditions at each part of their lifecycle. Countless hours have been spent inside our specialised breeding centre nurturing the tiny eggs, rearing the caterpillars and caring for their host plants as well as monitoring their final pupation period throughout the winter months.
“Butterflies have undergone a huge decline in the last 40 years in the UK, with more than 20% disappearing altogether as a result of habitat loss. So, it is incredibly rewarding to see large heath butterflies fluttering around in their new home – and know that we’ve contributed to bringing them back from extinction in this area.”
The main threat to the large heath butterfly in the UK is loss of the habitat which the species relies on to thrive, including peatland and boggy areas. A 2019 State of Nature report revealed that 41% of all UK species have declined and that at least one in ten now face extinction – with butterflies and moths suffering sharp declines of 17% and 25% respectively.
The team at The Lancashire Wildlife Trust have spent a number of years restoring specially chosen sites to their former glory and a handful of areas are now at a stage where they can support new populations of large heath butterflies once again.
Jo Kennedy, Great Manchester Wetlands Project Co-ordinator at Lancashire Wildlife Trust, added:
“Across our region we have lost 98% of our lowland raised bogs, creating a huge hole in our biodiversity. To function as a healthy ecosystem, we need a tapestry of different and connected habitats each supporting a variety of plants and animals.
“Boggy, healthy peatlands not only support that precious biodiversity, but also provide a vital natural resource in the fight against climate change. Healthy peatlands store huge amounts of carbon, but as soon as they are damaged this carbon is released into the atmosphere contributing to greenhouse gas emissions.”