12th May

A very memorable day with the arrival of Portland's first and Britain's 12th Moltoni's Warbler beside and later in the Obs garden a long-expected highlight. The bird proved far from easy to confirm, as much because it remained silent and so well-hidden for such a long time after first discovery but was eventually very satisfactorily clinched in every way; after release in the Obs Quarry it showed just once more before promptly vanishing. In an at times quite brisk northeasterly there was also a small arrival of grounded common migrants at the Bill that included 10 Spotted Flycatchers, 7 Yellow Wagtails, 5 Reed Warblers, 4 Wheatears and ones and twos of Sedge Warbler, Blackcap, Garden Warbler, Chiffchaff and Willow Warbler, along with a heavier passage overhead that mainly consisted of Swallows and House Martins, but had the likes of 30 Swifts, a Hobby and, more oddly, a Lapwing tagging along; the lingering Corn Bunting also remained at the Bill. Two more Great Northern Divers trundled past on the sea, with 7 Sanderlings and singles of both Red- and Black-throated Divers, and an Arctic Skua among the other loggings. 

If there's one bird we've been banging on about all spring it's been Moltoni's Warbler - every guest venturing out into the field has been given finding one as their mission for the day! So it came to pass that this morning no sooner had Jodie left the Obs on a patrol of the area than we received a call from her reporting a glimpse of an interesting-looking blue-backed warbler flushed from beside the lane to the Obs Quarry; Sue Parmenter was close by and she had an equally brief view of what looked like some warmth to the bird's underparts. Initial searches drew a blank but on a second circuit of the search area we stumbled across it furtively working through some dense cover right beside the Obs garden - views in the open were subliminal but a couple of snatched photos showed it to be a subalpine warbler. However, what used to be a doddle isn't any more so with rubbish views, a lousy photograph and no calls heard the ID couldn't get beyond subalpine sp - and we weren't even sure what sex it was!

With no further sign anywhere close to the finding spot the search area widened and a long time elapsed before we received another call - it had popped up in front of Nick Hopper on the far side of the Obs garden and, rather arrestingly, he'd heard a single rattle call from the same vicinity. We hastened to the spot via picking up a sound recorder and after a short wait three more rattles close by but from deep within cover confirmed the ID in our mind...

...Knowing that there was an open mist-net only a few metres behind the hidden caller a catch seemed almost inevitable if we walked through the cover towards it and so it proved:

The underpart colouration was so subdued that at first we weren't at all certain of the bird's sex but perhaps it's most likely a first-summer male - the upperparts look rather too blue-grey and the eye-ring too red for a female:

Although the wings looked brown in the field this wasn't due to heavy wear that might also have supported ageing as a first-summer; to the contrary, the wings were fabulously fresh for a spring Subalpine which is to be expected in many Moltoni's as they have a very weird moult regime that includes many moulting almost completely in winter. As far as we can make out the only obviously older generation feathers seem to be the two smaller tertials and perhaps the penultimate inner secondary - if these were very heavily worn they might be juvenile feathers which would support ageing as a first-summer but this doesn't seem to be the case so on moult pattern alone we're not sure that the bird can be conclusively aged:

The pattern of the second outermost tail feather, with the white tip squared-off, is as would expected for Moltoni's and Western Subalpine - an Eastern Subalpine should have a larger white wedge extending down the feather shaft © Martin Cade: