Thursday, 13 April 2017

Sedge warblers return

Naturalist and Norfolk Wildlife Trust volunteer Chris Durdin welcomes the return of the sedge warbler as spring is much in evidence at Norfolk Wildlife Trust’s Thorpe Marshes reserve on the edge of Norwich in Thorpe St Andrew.  
Sedge warbler, Derek Longe
April 8th and my first sedge warbler of the year at Thorpe Marshes is singing, half-hidden, in last year’s reeds. It makes me wonder why it’s an exciting moment. The scratchy song has a relentless energy, which appeals to me, though that description also applies to the wren singing close by.

It’s looking like an advanced season for nature with the recent warm weather, for now at least. It’s certainly a good time to visit NWT’s reserve in Thorpe St Andrew on the eastern edge of Norwich. As well as spring bird song, marsh marigolds are in full flower and lady’s smock is coming out, too. Around the latter are orange-tip butterflies – for both nectar and as it’s a larval food plant – which also means the start of the survey season for some of the reserve’s volunteers. For a third year we are counting orange-tips (essentially in April and May) and Norfolk hawker dragonflies (June and July). So if you see someone on the reserve with pen and paper it may be Derek, Susan or me – but feel free to stop us for a chat, we can all multitask!
Orange tip butterfly on cuckoo flower, Derek Longe

My focus on the sedge warbler is for two reasons. One is simply as it’s a new arrival from sub-Saharan Africa, a reminder of the miracle of migration. The second links, I think, with keen birdwatchers’ constant search for the new or different. Yes, they’re back – like seeing an old friend after many months of absence. I haven’t heard a sedge warbler for ages.

What strikes as noteworthy is framed by both timing and place. For example, at Thorpe Marshes in 2017 to hear a Cetti’s warbler is routine, the strident song of this resident species much in evidence through much of the year. But go back a couple of decades and this bird would have been the surprise and across the UK – including in spring at Thorpe Marshes – it’s still scarcer than a sedge warbler. So unusualness depends on where and when.

Marsh marigold, Chris Durdin
I start to think: if I’d been there yesterday or the day before, could I have recorded an earlier sedge warbler? This train of thought, on reflection pointless competitiveness, is broken by the sight of male marsh harrier, with tri-coloured wings, flying low over the marshes. The harrier flushes a snipe, twists over the reeds where the sedge warbler was singing and heads up the valley towards Norwich. Moments later the call of a lesser black-backed gull encourages me to look upwards to where the gull is harrying a buzzard. 

Chris Durdin leads monthly wildlife walks at NWT Thorpe Marshes. Details of monthly walks on