“What it shows is the slow, but steady, expansion of the breeding range of the great bustard – and that the bustards had a good year last year,” said David Waters from the GBG.
The bird has been Wiltshire’s county emblem since Wiltshire Council was established in 2009.
Speaking to BBC Radio Wiltshire, Waters said the UK population, which is all in Wiltshire, are doing well.
“The numbers are going up slowly. But in the rest of the world, many of the Great Bustard species are not doing well,” he added.
“They’re the only bird in the UK which is globally endangered.”