Not long after 09:10 on 7 October, Tim Davis and I were walking along the north side of Millcombe, the valley containing the largest area of trees on Lundy, Devon, towards the end of a two-week stay on the island. I glimpsed a warbler with a prominent supercilium and wing-bar and said: "I think I’ve got a Yellow-browed Warbler", having seen two on 5 October, including one in Millcombe. Tim quickly corrected that, saying: "No, it's not a Yellow-browed… What the hell is it?!"
The bird then showed quite well, if briefly, to both of us as it moved through the sycamores. We noted a single wing-bar, very long supercilium, orangey bill and generally bright plumage. I was particularly struck by the yellowish tones, but with no field experience of Green Warbler and only a little of Greenish Warbler, was unsure how yellow was 'too yellow'. We did mention to each other at this stage the possibility of Green Warbler, but were clearly too quick to dismiss the notion of something so preposterously rare! The bird dropped down and disappeared from view. We spent a few minutes trying to relocate it but it seemed to have done a runner.
Initial sightings of the warbler suggested a bright green bird with strong yellow wash to the face and underparts, but views were brief and often obscured (Tim Jones).
Both of us were needed elsewhere, having promised some voluntary time to support island staff, and couldn't get back to Millcombe until noon when, to our huge relief, after about 25 minutes' searching, we found the bird feeding in trees on the opposite side of the valley, alongside Common Chiffchaffs and Goldcrests. We again watched it moving through the canopy at some speed, often against the light, which made snatching record shots with a bridge camera quite a challenge. The bird was constantly moving ahead of us and once more dropped out of sight after about 10 minutes. It was not until 14:30 that we caught up with it once more, but again it was moving away. At 15:25 it was in trees further down the valley, when it rested in the semi-open for a minute or two, enabling some better record shots to be taken. We last saw it at 15:45.
Altogether we estimate that we watched it for about 40 minutes. Posting two photos on the Lundy birding blog as 'Greenish Warbler' shortly afterwards quickly unleashed a Twitter storm that we were only partly able to keep up with from the island, but it soon emerged that we had stumbled across Britain's fifth Green Warbler, also a first for both Lundy and Devon! Unusually for any point in October, we were the only birders on the island and sadly, though 34 twitchers endured the unpleasant trip across in small boats amid blustery winds and drizzle on the Monday morning, it soon became clear that the bird had done an overnight bunk.
We'd like to thank everyone who contributed to pinning down the identification from afar – it was great having such support from the online birding community.
The bird eventually showed well enough for a series of images to be taken, clinching the identification beyond doubt as Britain's fifth Green Warbler (Tim Jones).