Wednesday 22 February 2017

'The times they are a-changin’ - NWT Thorpe Marshes

Naturalist and Norfolk Wildlife Trust volunteer Chris Durdin reflects on 'new nature' and how wildlife responds to climate change at Norfolk Wildlife Trust’s Thorpe Marshes reserve on the edge of Norwich in Thorpe St Andrew.

Approaching dusk in February, and there’s a loud burst of song: a Cetti’s warbler
Cetti's warbler by Elizabeth Dack
. It’s an unremarkable record in 2017 for this bird, unusually among warblers a resident species.

But it’s a reminder of how wildlife responds to changes in climate. Cetti’s warblers first bred in Britain in Kent in 1973 and they soon moved into the Yare Valley. Broadland is now a stronghold and they are also found in wet scrub in much of the south and east of the UK.

There are plenty of other examples of ‘new nature’ on my local patch. We see little egrets fairly regularly. The first little egret I saw, in my student days, was in the Camargue in the south of France, and I can clearly recall my first in Norfolk, on Breydon Water, years later. Today it’s a distinctive and easily-recognised Broadland bird. Like Cetti’s warblers, numbers can be hit if there is a long cold spell, but how often do we get weather like that?

The Migrant Hawker dragonfly was once known as Scarce Hawker, and the new name came after regular appearances in the UK in the 20th century. Now well-established as a breeding species, it’s often the commonest dragonfly at Thorpe Marshes in late summer and with luck you can see them laying eggs. 

Speckled wood butterfly by Elizabeth Dack
More recently arriving still is the Willow Emerald damselfly, breeding in Britain for just a decade, but in good numbers at NWT Thorpe Marshes, elsewhere in the Broads and beyond. The northward spread of the speckled wood butterfly is another example.  

Losses related to climate change can be more difficult to pin down. Snipe used to ‘drum’ – their distinctive breeding display – at Thorpe Marshes when I first knew the area but have stopped breeding here, as in much of lowland England. Climate is probably partly at issue, but also subtle habitat changes. Willow warblers are getting scarcer, and cuckoos too, but for these and other birds that winter in sub-Saharan Africa other factors play a part.
For me, spotting how wildlife responds to changes in climate is obvious: what my eyes and ears reveal backs up what climate scientists say. Perhaps the climate change sceptics are less in tune with the natural world. Writing here, I hope I am preaching to the converted … and that naturalists everywhere will use the evidence of nature to challenge the cynics and doubters.

Discover Thorpe Marshes
Chris leads monthly wildlife walks at NWT Thorpe Marshes. Details of these and recent sightings on the reserve are on The website also has the 15-page NWT Thorpe Marshes Wildlife Report for 2016.

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