Saturday 20 September 2014

A gem of an emerald

Chris Durdin, NWT Thorpe Marshes
Is nature predictable or unpredictable? Discuss, as exam questions used to say. A recent discovery at NWT Thorpe Marshes was, you might say, a predictable surprise… so perhaps the best of both.

That discovery was a new damselfly for the reserve on the edge of Norwich. Willow Emerald is name of the species, or Western Willow Spreadwing in the European field guide. ‘Spreadwing’ is from the position at rest of this and related species, as the photo shows. This damselfly perched on a sallow twig, a typical pose.

Willow Emerald Damselfly Chalcolestes viridis

The Willow Emerald is a recent UK colonist, first found in Suffolk in 2007. It’s now fairly widespread in the right habitats in our neighbouring county, and spreading. It's been at RSPB Strumpshaw Fen for a few years, and was seen well on the River Yare at Cringleford in 2013. As NWT Thorpe Marshes is midway between Strumpshaw and Cringleford, I mentioned Willow Emerald on my September guided walk as a damselfly to lookout for.  Hey presto … one of that group returned and found it. I hear they’ve also been found in several other places this year.

It took me three attempts to see the Willow Emerald for myself, but warm autumn days meant there were many dragonflies on the wing to keep me company. And, on one visit, a whinchat, too: an autumn migrant, so when you might expect to see it, but far from predictable.

Incidentally, the Willow Emerald brings the reserve Odonata list to 19. That’s slightly fewer than Strumpshaw Fen's 24 (22 breeding species, 2 vagrants). Do any blog readers know how other Norfolk sites compare? In another role, as a soccer coach, I know I must keep the lid on the ‘competitive dad’, but I can’t help but wonder how my local patch ranks against more famous nature reserves.

Would anyone like to predict what we’ll find next at NWT Thorpe Marshes?

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1 comment:

  1. A second sighting today of the Willow Emerald damselfly in the garden. It allowed me close enough to see what a stunning creature this is. It sat on a dead bloom of a Buddleia, its slender emerald body shimmering in the sun. Thrilled to have it and do hope it decides our ponds become home.