Meet the scientist
Reintroducing harvest mice to Northumberland
We’d spent months lovingly breeding these mice, so we didn’t want to release them all in one go.
Back in 2004, harvest mice were found no further north than Durham in the UK. But Wendy Fail, a PhD student at Newcastle University at the time, came up with a plan to change that.
“They hadn’t been seen in Northumberland for a number of years,” she says, “so, we decided to see if we could reintroduce them.”
After consulting experts and recruiting volunteers, she and her team set about breeding a captive population of 240 mice for release, from animals donated by Chester Zoo and “a chap in the Teeside area who happened to have some”.
Having identified a prime reedbed habitat in East Chevington nature reserve, south of Amble, they could start releasing them. “We’d spent months lovingly breeding these mice, so we didn’t want to release them all in one go, because we could have lost them all at once.”
Instead, they went for a softer release strategy. “Over about eight weeks, we placed a few at a time in acclimatisation cages with food and water. At first, the doors were closed, but we opened them after a week so they could make their own way out,” Fail explains.
The moment of truth came six months later, when the team conducted a trapping survey to see if the mice had established themselves. “We caught plenty of shrews, voles, wood mice and a very angry weasel, but no harvest mice,” she says. “We came to the conclusion that it hadn’t worked, so off we went, a bit disappointed. But, you know, you carry on.” She took a job with the council as a rights-of-way officer then as a nature reserves officer, retrained as a teacher, and now works in environmental education with Groundwork, a charity that promotes sustainable community development.
“I never forgot the harvest mice,” she says. “They’ve always been at the back of my mind.” But then, last November, a phone call from one of the volunteers brought news that unmistakable signs of harvest mice, in the form of tennis-ballsized woven grass nests, had been found at the reintroduction site.
“It was completely out of the blue,” says Fail. “To say I was over the moon is a bit of an understatement.” She is “99 per cent certain” that the nests are the work of descendants of the mice she released. “Given the home range of a harvest mouse is quite small – 400m² or so – the chances of them travelling up from Durham are very slim.”
Fail hasn’t been back to the site yet, but is looking forward to becoming a volunteer herself on the project she started. “I’d be more than happy to get involved in some trapping and survey work again, given the chance – see if I’ve still got the knack.” Stuart Blackman