A Hertfordshire comeback story of Water Voles – famous to generations as ‘Ratty’ in the children’s novel Wind in the Willows – was told at the HNHS annual meeting, held online on Saturday 27 November.
Josh Kalms, People and Wildlife Officer with the Herts and Middlesex Wildlife Trust, described the careful process by which 150 of the bank and stream dwelling creatures were reintroduced to the River Ver this summer.
Fifty years ago, Water Voles were still a relatively common species in Hertfordshire’s chalk streams. But the species has undergone a catastrophic decline attributed to factors that include habitat loss, commercial over-extraction of water, extreme weather and predation to extinction along some rivers by feral American Mink.
Water Voles relocated from Essex coastland have already been successfully reintroduced to Thorley Wash near Bishop’s Stortford, but those released along a 2km stretch of the Ver were young animals purpose-bred in Devon, with the exception of four sexually-mature adults.
Josh explained that 18 month’s work to prepare for the release included surveys to assess the site’s suitability and deployment of six electronically monitored Mink trapping rafts. These importantly confirmed that no Mink were present.
The Water Voles were then placed near the river in pens where they were attended and fed daily. After a few days to settle in, the pens were then modified so the animals could come and go as they chose. They are the first Water Voles to be seen along the Ver since the 1980s and will be annually monitored to assess breeding success and population density.
Although liable to be treated as “nature’s chocolate biscuit’ by predators as varied as Stoat, Grey Heron and Pike, the Water Voles are expected to do well. They are also likely to have a positive impact on biodiversity, creating space and light for additional flora among the reeds and leaving old burrows that can be used by other, native species. “They should slot into the local food chain very well,” said Josh.
Water Vole photograph © Andrew Miller
Southern Emerald Damselfly, St Albans, July 2021 © Rupert Evershed
The annual meeting, attended online by 45 members and guests also heard from Odonata recorder Roy Woodward about plans to start a six-year county-wide survey of dragonflies and damselflies that has previously been postponed because of the Covid pandemic. Roy noted that the number of species confirmed for Hertfordshire has risen from 24 at the time of the last survey from 1998-2007 to 33. New arrivals include the now-widespread Willow Emerald Damselfly and, most recently, a Southern Emerald Damselfly found in a St Albans garden this July.
The survey will map species by 2km-square tetrads with all records welcome – not least from gardens with ponds. Roy’s objectives are to map all species present in the county, record evidence of breeding, measure flight periods, estimate abundance and gain an indication of habitat preferences.
A survey sub-site is being created on the HNHS website where observers will be helped to provide a six-figure grid reference for their sightings. Advice on identification and on providing evidence of potential breeding will also be provided.
A further appeal for all county records was made at the meeting by Chantal Helm – but this time for the mammal, amphibian and reptile survey (Herts MARA) which will reach its final year in 2022. Chantal was especially keen to encourage records from tetrads with five or fewer species currently confirmed. Details can be found on the MARA sub-site.