Friday, 21 October 2011

Shingle session

Twite, Purple Glasswort and Sea Pea.

The coastline between Dunwich and Walberswick in Suffolk supports some excellent shingle and lagoon habitat. Yesterday was spent wandering around the Dingle Marshes thinking about some of the key issues. Sea level rise is a major threat to this stretch of coast and recent inundations have pushed the shingle back, creating some great looking habitat for Little Terns and Ringed Plovers, or it would be but for the heavy disturbance in this popular holiday area. The remains of Sea Pea and Sea Kale were evident but such specialist shingle plants are also suffering from trampling.  Almost the first bird I saw was a Glossy Ibis, flying up from one of the pools and disappearing over the ridge towards the Walberswick reedbeds. However I spent rather longer watching some more typical winter visitors – a flock of 16 Twite feeding where the shingle meets the saltmarsh.

Twite wintering on the east and south coasts of England are thought to be mainly, or entirely, from the small south Pennines breeding population. It is possible that small numbers of Twite from Norway also winter in this area, although no Norwegian-ringed birds have so far been recorded in the UK, despite the large numbers ringed in Norway. The number of Twite wintering on the east coast have declined substantially over the last few decades. Flocks of thousands were noted around The Wash back in the 70s and 80s but now the latest estimates are of no more than 450 birds between the Humber and Kent. The Dingle/Dunwich area remains the main locality in Suffolk. Wintering Twite feed on the seeds of Glasswort, Annual Sea-blite, Sea Lavender and Sea Aster, with late winter distribution shown to be strongly related to the density of remaining Glasswort seeds.

Half a dozen Spot Shanks, several Greenshank, Knot, Dunlin and Grey Plover fed around the shallow lagoons behind the beach with a number of Rock Pipits and at least one Water Pipit. Redwing, Fieldfare and Siskin calls constantly reminded of small parties passing overhead. A Red Kite drifting south completed a reasonable morning.

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