I went to look and it was a surprisingly emotional moment. It's taken a lot of work and effort over several years - it was a good moment.
English-born chequered skipper butterflies are flying in the UK for the first time in more than 40 years as part of a conservation project, experts say.
A second batch of the butterflies collected from Belgium have been released at a secret location in Rockingham Forest, Northamptonshire, as part of efforts to reintroduce the species, which had become extinct in England.
And butterflies introduced from Belgium last spring have successfully bred in the woodland - with their English-born young now on the wing, wildlife charity Butterfly Conservation said.
Chequered skippers became extinct in England in 1976, as a result of the destruction of their wet woodland habitat in the East Midlands, when woods with the open glades and rides they favour were cleared and replanted with uniform conifers.
Dr Nigel Bourn, of Butterfly Conservation, said: "It was a very rapid extinction that took everybody by surprise.
"They were recorded in quite good numbers in the 1950s but went extinct in the next 20 years, and it comes back to their habitat."
Butterfly Conservation is running the three-year project to bring them back in partnership with Forestry England, which manages Rockingham Forest.
The releases in 2018 and this year follow work to restore parts of the forest, once a stronghold for the chequered skipper, to create the ideal conditions for it with wide, flower-filled rides.
Dr Bourn describes seeing his first English-born chequered skipper, which he spotted while preparing the Belgian insects for release in the woods, as a "surprisingly emotional moment".
"We had the Belgian chequered skippers in a net to acclimatise before releasing them and were marking them, and as we were doing that, one of the volunteers said, 'Here's an English one'.
"I went to look and it was a surprisingly emotional moment. It's taken a lot of work and effort over several years - it was a good moment."
The butterfly has only a "toe-hold" here, he added, and a further release of new butterflies is planned for next year to boost numbers and help the insect establish a sustainable population across the landscape.
Forestry England ecology and heritage manager for the Central England district Adrienne Bennett said: "We are thrilled that the hard work by Forestry England staff over many years has created the ideal habitat for the reintroduction of the chequered skipper on our site.
"We hope the butterfly thrives and the population is able to spread from here."
The reintroduction forms part of the Roots of Rockingham project across a number of sites to restore the forest to its former glory and help woodland species such as the willow tit, lesser spotted woodpecker and barbastelle bat.
The chequered skipper is one of a number of species being helped by the "back from the brink" project led by Government conservation agency Natural England to save 20 species from extinction and boost more than 200 others.
Back from the brink is being backed by the National Lottery Heritage Fund and the People's Postcode Lottery.
Emily Beament is the Press Association environment correspondent.