Tuesday, 23 October 2018

There were some big counts from the sea again this morning, with 1288 Black-headed Gulls and 4141 Kittiwakes moving past in large feeding flocks. Amongst them 52 Mediterranean Gulls were mixed in and several Great Skuas harassed the lot. On the land, the tricky Lesser Whitethroat that has been skulking in the bushes around Ty Capel and Ty Nessaf was finally caught, and in-hand measurements confirmed our suspicions that it is a good candidate for the central Asian subspecies blythi. Amongst an entertaining supporting cast included the first two Jack Snipes of the autumn, a Barn Owl at Nant, three Great Spotted Woodpeckers roaming the island and a Black Redstart around the Abbey ruins.

89 Gannets, a Grey Heron, five Brent Geese, ten Common Scoters, two Sparrowhawks, two Buzzards, three Kestrels, a Merlin, three Peregrines, a Water Rail, eight Purple Sandpipers, a Dunlin, two Jack Snipes, 11 Snipes, two Whimbrels, 34 Turnstones, 17 Common Gulls, 4141 Kittiwakes, two Little Owls, two Skylarks, two Pied Wagtails, 11 Stonechats, 14 Song Thrushes, ten Redwings, a Blackcap, five Chiffchaffs, seven Goldcrests, eight Blue tits, seven Great tits, three Jackdaws, 33 Rooks, 64 Carrion Crows, 29 Chaffinches, four Bramblings, four Greenfinches, eight Siskins, 19 Goldfinches, two Linnets, four Lesser Redpolls and a Reed Bunting.

A combination of wing formula and the extent of white in the outer-tail feathers make this look a good match for Siberian Lesser Whitethroat (Sylvia curruca blythi). A loose feather was collected for DNA analysis which should help confirm the identity. 

Autumn is a great time to look for moths in their larval stage. The caterpillars of many species of micro moth create distinctive feeding signs in leaves of different trees. This leaf 'fold' was found on Damsons behind the Observatory garden a few days ago. It's made by a tiny nondescript moth called Parornix torquillella. The feeding damage is identical to that created by Parornix finitimella but the larva has pale legs instead of black legs which confirms it as P. torquillella.

This is a leaf mine on Apple made by Stigmella malella. It's an old one; the larva has vacated the mine earlier in the autumn to pupate elsewhere but you can still see the remains of dark broken 'frass' (i.e. poo) in the earlier, narrower part of the mine. The pattern made by the frass combined with the shape and position of the mine are the main features to look at when identifying them. Both of these are new species for the island. 

Enough about moths. It was a stunning autumn sunset, even when seen through the grimy office window.

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