We'll be honest. We were starting to think about our summer holiday. We'd leave Bardsey today and head up North via the rather stonking Little Swift. But the weather isn't in agreement. Raging 30mph Southwesterlies mean we're staying, at least for today. It's a good job too! For the second time this month, a male Greenish Warbler burst into song this morning. Not the easiest bird to see in swirling, dense foliage, but a brief but good view of the bird, coupled with its distinctive song, meant we were pretty happy about the identification. But as the wind dropped the bird also made the convenient decision to move to the sheltered side of Cristin Withy. A net could be opened and we were soon holding this tenth for Bardsey, the third to be trapped in three years and the second this month!

This individual showed a more distinct wingbar than the bird earlier this month. A second wingbar was also faintly visible along the edge of the median coverts. The bird was in good condition with healthy fat and muscle scores. It was released into the Observatory garden where it has continued to sing on occasion. (c) Richard Brown

There can't be too many places with a ringing schedule looking like this! Outside of Eastern Europe or Russia that is. Two Greenish Warblers ringed 22 days or seven AA rings apart. (c) Richard Brown

Apologies for the lack of blogs recently but it's all been a bit manic. Our fantastic late spring feels like it's pretty much over but a skulking Acrocephalus in the Obs garden gave us hope yet again. Sadly it wasn't nailed before torrential rain set in. Torrential rain around the new moon period in June usually means Manx Shearwaters at the light, and this is exactly what's been happening. It means we don't get too much sleep as we monitor how many birds are attracted. The last two nights have totalled more than 400 attracted with 73 trapped, including a control, and eight killed. The rain has been so intense that many of the Manx Shearwater burrows on the South End have completely filled with water, bedraggled adults sitting in the entranceways with their eggs presumably submerged.

As soon as the weather improves it gives us a chance to get around to the East Side of Bardsey where our seabird colonies are. We've managed to get to all the major Razorbill colonies and productivity, despite the weather and a rather protracted breeding season this year, is looking pretty good. The large gulls, despite fewer pairs attempting to nest, are also looking good in terms of productivity, particularly the Lesser Black-backed Gulls. (c) Richard Brown

Kittiwake productivity is also looking excellent, with most of the nests still holding two chicks. However, the number of adults which returned to breed this year was one of the lowest on record. Perhaps the two are linked? (c) Richard Brown

Adult Razorbills, returning to the colony with fish for their single chicks, often linger for long enough to allow for views of their rings. This bird, M94885, was ringed as a chick in 2000 at the same site that it is now rearing its own. More impressive is M23170, last seen in 2004, which had reached the staggering age of 41 years, 11 months and 23 days, the world's oldest Razorbill. (c) Richard Brown

Although we're now flat out with monitoring our breeding birds, we still had time to twitch Rolf Harris who spent two days filming on the Island.

The 2010 Annual report has just had a fantastic review on Birdguides (read it here: http://www.birdguides.com/webzine/article.asp?a=3311).

A quieter couple of days were brightened up by an extremely confiding Pomarine Skua which spent most of this morning touring the Island. The wholly dark underwing suggests that this bird is a full adult and the lack of a breast band is considered to be a feature of some male birds.

Genetic studies have shown Pomarine Skuas to be most similar to Great Skuas, in fact the two species have one of the smallest mitochondrial DNA differences of any two vertebrate species that have ever been analysed. But observations on morphology and behaviour show Pomarines to be most similar to Arctic Skua. So, how can a skua be so closely related to one species (genetically speaking), yet display many of the characteristics of another? Well, it is thought that Poms have evolved from an extensive hybrid population of Great x Arctic Skua. The last two photos show the Shelduck's displeasure for today's avian highlight. This particular pair of Shelduck have also forcibly removed the parents of two broods of Solfach Shelduck. Happily they have adopted the two broods, taking the number of chicks in their own mega-brood to 18. (c) Richard Brown

Our recent good run of birds continued this morning as we reached the Narrows. A stunning male Yellow Wagtail with black ear coverts, a blue grey crown, long white supercilium and mainly yellow throat. Mr. Stansfield muted 'dombrowskii' as a good candidate and this feldegg x flava intergrade certainly looks like a good possibility. However these seem to be indistinguishable from the dark ear coverts form of tschutschensis Eastern Yellow Wagtail, at least in appearance. However the call seemed as flava, not the buzzy Citrine Wagtail type call associated with tschutschensis. So dombrowskii is the more likely, but we'll probably never know quite what he is, but he's a cracker none the less. 

A rather flighty little fellow, we later found him half a mile to the North of the Narrows feeding around the cattle troughs. Incidentally Tschutschensis refers to the Chukhotski Peninsula in Siberia. (c) Richard Brown

Almost two years to the day since the last Bardsey Greenish Warbler was picked up on song, today saw it happen again with a vocal bird at the farm relocating to the Observatory. In horrendous weather the gathered crowd were only managing fleeting glimpses as it sang from cover. Happily it made its way into the Heligoland Trap (yet again a big thank you to Mr Hugo Weigold (who incidentally was apparently the first Westerner to see a live Giant Panda in the wild)). This is the ninth Bardsey record and the ninth to be reported in the UK so far in 2012.

The top photo is of today's bird and the lower photo is the bird found whilst trying to locate the White-throated Sparrow on 11 June 2010. Both adult and first-winter Greenish Warblers undergo a complete moult in their Indian wintering grounds so we can't age the birds. The difference in wear to the greater coverts is particularly striking between the two individuals, with today's bird almost lacking a wing-bar entirely. (c) Richard Brown

If we were on the mainland a very brief, through-a-window view of a middling sized, dark winged, yellow rumped bird undulating down a net ride would probably turn out to be a Green Woodpecker. On Bardsey it was almost certainly a Golden Oriole as these are recorded annually (there has only been one record of Green Woodpecker since the early 1980s). Sadly the bird was not seen again. One, possibly two, unrung Common Rosefinch have put in brief appearances and the Melodious Warbler continued to sing up until yesterday. Bird of the day was a Red-breasted Flycatcher at Nant. Of approximately 75 previous Bardsey records only nine have been in spring, all but one in June.

There have been some interesting studies into the body mass of long distance migrants. Chernetzov et al 2007, compared the body mass of Red-breasted Flycatcher and Blyth's Reed Warbler, two species which have to cross the arid belt of Western Centrel Asia in Spring and Autumn. Blyth's Reed Warbler had a much greater relative body mass prior to the crossing than Red-breasted Flycatcher, but they both have to cross the same distance. So why would one species need more fuel reserves than another? The answer is foraging ecology. Flycatchers can't catch flies if they're carrying too many grams. It would be like an obese human having to jump into the air to catch cheese-burgers. Sort of. Similar observations were made on the Spotted Flycatcher, before, during and after crossing the Sahara. So flycatchers just have to gain mass at low rates and hope that they encounter plenty of insects along the way. Unfortunately we did not catch today's Red-breasted Flycatcher, but the one we caught last Autumn had a fat/pec score of 0/0. Perhaps it was a score not as bad as it seemed. (c) Richard Brown

The weather today was appalling. Heavy rain at angles approaching the horizontal kept the majority of observers indoors for the majority of the day. Happily Hugo Weigold developed an apparatus on the German island of Helgoland whilst establishing the first bird observatory there. His funnel trap meant that birds could be trapped in weather where other trapping techniques could not be used. Just such weather is a regular feature of Bardsey and the Heligoland Trap in the back garden of the Observatory means we can catch a few birds when the mist nets are not an option. Today we owe Mr Weigold quite a thank you as his trap produced both a Woodchat Shrike and a Melodious Warbler.

The first two images show today's bird and the bottom shows last year's bird of 20 May. Retained juvenile feathers show today's bird to be a first year. The black mantle, forehead and ear coverts show it to be a male, a female looking like last year's bird. The white primary bases extend beyond the primary coverts by 7mm, as would be shown by the nominate form. (c) Richard Brown

Both adult and first-year Melodious Warblers typically undergo a complete moult in the winter. Despite this, this afternoon's bird showed two distinct feather generations, with generally well worn plumage but some replaced tertials, inner secondaries and outer tail feathers. The neat, pale edges to the replaced secondaries form a little bit of a wing panel but the obvious small size and short-wing immediately rule out any confusion with other species. (c) Richard Brown