How biodiversity in the Fens is helping kingfishers, otters, water voles, bats and even the black poplar, the UK’s rarest timber tree

Water voles on local drains, Hundred of Wisbech Internal Drainage Board (Image: Archant)

Updates on the biodiversity action plan partnership, that covers 36 drainage boards, were presented to a Middle Level meeting at the Oliver Cromwell Hotel, March.

The meeting heard some of the results of the first five years of the Middle Level biodiversity partnership.

Its aim is to promote actions that will benefit wildlife diversity without affecting drainage management requirements.

Cliff Carson, environmental officer, said: “It is easy to overlook the wildlife of our man-made drains and ditches but there is a wealth of interest for those that take the time to look for it.”

Among the animals that have benefitted from the biodiversity plan is the kingfisher, which now has 150 safe nesting holes and chambers spread over 80 different sites.

Mr Carson said that to provide nest sites “for these jewels of our waterways” 150 holes have been drilled during the last five years through steel, brick and concrete structures at 80 Internal Drainage Board (IDB) sites.

He said: “When a 50 to 70mm diameter hole is drilled through steel piles or concrete headwalls that have soil behind them an opportunity is created for kingfishers to establish very safe nesting tunnels and chambers.

“Natural nest sites in riverside soil cliffs are often quickly eroded and only last a few years but sites like these behind steel piles will remain available for more than 20 years.

“2015 has been a boom season for kingfishers in the Middle Level with many more sightings than usual reported from drains and rivers throughout the area.”

Other species that have benefitted in the five year biodiversity plans of the 36 IDBs have been bats, barn owls, water voles, otters and black poplars.

Otters have benefitted from the construction of 79 otter holts (dens) in the banks of Middle Level waterways and spraints (signs of their presence) have been recorded at over 60 bridges throughout the 120 miles of drains and rivers in the catchment.

Eight two large panel bat boxes have also been attached to pumping stations and 26 bat bricks have been installed in culvert tunnels.

140 black poplars, the UK’s rarest timber tree, have been planted from cuttings taken from local trees and have been established at new sites throughout the Middle Level.

91 barn owl boxes have also been erected throughout the 36 districts, making the Middle Level of the Fens a stronghold for the species.

It is also a stronghold for water voles, with 1,770 meters of coir rolls pre-planted at 23 sites to create ‘instant habitat’ for water voles, provide pollen for insects and to stabilise bank margins.

Mr Carson added: “The commissioners, together with local drainage boards, operate a complex flood protection and water level management system to balance the various water uses and requirements and to alleviate the risk of flooding of land and properties.

“The efficient operation of the system is vital to the safety and prosperity of over 100,000 people who live and work in the area.

“But for the operations of the commissioners and boards, the majority of the Fen land would be under water for much of the year, accesses from higher ground would be cut-off and many of the present land uses, which are taken for granted, would be impossible.

The 70,000 hectare Middle Level catchment is also a national stronghold for water voles. 1,770 meters of coir rolls pre-planted with native marginal water plants have been installed at 23 sites to create ‘instant habitat’ for water voles, provide pollen for insects and to stabilise bank margins.