Thursday, 2 September 2010

Starlet steals the show

View across Havergate (with 14 Spoonbill), Avocets arriving at high tide, Starlet Sea Anemone - a rare specialist of coastal lagoons.

Equipped with sifting trays, nets and a supply of red wine, I had Havergate Island to myself for two days. The aim was to undertake a survey of the saline lagoon fauna but with a light easterly blowing, I was hoping for more.

Famous as 'Avocet island', recent years have seen a dramatic change in bird populations on the island. From zero a few years back, the island now supports 1200 pairs of LBBG and 600 pairs of Herring Gull. The increase in gulls has resulted in a corresponding decrease in breeding Avocets, Ringed Plovers and terns, due to predation. The gulls have moved to Havergate from Orfordness, where they have been decimated by Fox predation. However recent years have also seen an increase in Spoonbills, with counts here or at the adjacent Orfordness being the UKs highest, 14 were still present during the visit.

The lagoons at Havergate are also important for their specialist invertebrates. The sampling revealed a high biomass within most lagoons; ragworms, the amphipod Corophium, Lagoon Cockles and abundant Palaemonetes shrimps, but perhaps the most important saline lagoon specialist is the Starlet Sea Anemone. However, with a body only 2-3mm long, this is not the most obvious beast.

Avocets still favour Havergate for feeding, 620 were present, along with 250+ Redshank and 50+ Black-tailed Godwits. Other bird highlights included 50 Common, 26 Sandwich, 1 Arctic and 1 Black Tern, Peregrine, Hobby, 3 Pintail, 15 Greenshank, 2 Spotshank, 10 Knot, 60 Golden Plover and 28 Bar-tailed Godwit. Passerine migrants were represented by a Reed Warbler, a few Wheatears and a Rock Pipit. Could have been better, but the sunset was worth it.

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