Saturday, 13 April 2013

Bringing back rabbits to Newborough

I met up with Graham Williams, senior reserve manager for Natural Resources Wales, at Newborough Warren national nature reserve. Covering a thousand acres it’s the largest dune system in the country but whereas fifty years ago it was 60% bare sand, today it is covered in a dense mat of vegetation down to just 3% sand. You can hear Graham talking about the dunes on Country Focus which will be broadcast on Sunday 14th April and available on the iPlayer for the following week.

Why the vegetation? Warren is the clue - in the good old days there was a huge population of rabbits, trappers catching 15,000 in a year, but in 1953 myxomatosis almost wiped out the population with but a few these days. Thousands of rabbits are great dune managers, grazing the vegetation and burrowing to create piles of loose sand that get blown around to form dunes. Today Graham uses ponies for grazing but sadly they are no good at digging holes.

Increased nitrogen deposition and increased CO2 levels have contributed to the vegetation growth as has the succession of wet winters and summers; also wet sand can’t be blown around.

So what? Bare sand is the lifeblood of a mobile dune system which in turn provides extreme, hot and dry habitats for rare species such as mining bees, sand wasps, beetles, and plants like petalwort. Several of these species are on the brink of extinction so intervention is underway.

Rabbits have been re-introduced in the form of giant diggers and twenty-five-tonne dumper trucks which are stripping and moving the vegetation from a 3 to 4 acre section of the dunes. Hopefully this will create a safe haven for the endangered species and a platform from which dry sand can be blown to smother vegetation, create more bare sand and get the dunes back to my childhood memory of what they should be.

Rabbits seem to be the key but if the rabbits didn’t get here until the Romans, what would the dunes have looked like then?

What I love about blogging is the near immediate response you can get and I am grateful to Mike Howe for the comment below:

Much of the sand body of Newborough Warren post-dates the Roman occupation of Anglesey by about 1200 years. The text below is taken from: Pye & Blott (2012). CCW Science Report 1002.

The timing of the earliest sand invasion at Newborough has not been established. However, there is evidence to suggest that a major episode of aeolian sand incursion occurred in the 13th and early 14th centuries, when significant areas of cultivated land were abandoned (Ranwell, 1958, 1959, 1960a)

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