30th June

With our mobile raingauge - the wheelbarrow we'd left in the middle of a lawn at the Obs when the job we were working on begun to get rained off on Tuesday - measuring 8cm of rainfall in two and a half days it was something of a relief when sunny skies quickly replaced the drizzle of today's dawn. The Common Rosefinch took advantage and sung for a while at Southwell, but new arrivals consisted of just 5 Dunlin and a Willow Warbler grounded at Ferrybridge and the Bill respectively, 2 Sand Martins, a few Swifts, a Little Egret and a Whimbrel at the Bill and a Greenshank over Ferrybridge. Another 43 Common Scoter and 2 Sandwich Terns passed through off the Bill where upwards of 50 Manx Shearwaters were feeding offshore.

The gradual shift to a northwesterly wind direction saw immigrant moth numbers dwindle, with 17 Silver Y, 16 Diamond-back Moth, 9 Dark Sword Grass and 8 Rusty-dot Pearl making up the bulk of the numbers at the Obs; oddities there included singles of European Corn-borer, Hummingbird Hawkmoth, Pine Hawkmoth, True Lover's Knot and Scarce Bordered Straw.

By the look of the shoddy state the Common Rosefinch has got into it's already starting to moult so may well be ensconced for the duration © Pete Saunders:

...not that being in moult necessarily precludes moving about quite a bit: this morning's Willow Warbler trapped at the Obs was presumably a failed breeder (it was a female with a good brood patch) already well into its post-breeding moult; we're not sure how far away Willow Warblers breed these days but it certainly hadn't come from anywhere on Portland © Martin Cade:

One thing that hasn't failed to breed is this local Common Buzzard...

...its young look to have had Pheasant on the menu today © Pete Saunders:

Finally, a routine although always popular moth from the traps - a Drinker © Tony Hovell:

29th June

Such was the frequency of outbreaks of the day's mainly drizzly rain that coverage was again less than comprehensive. The Common Rosefinch remained at Southwell, whilst there were new singles of Grey Heron and Curlew over the Bill and Whimbrel at Ferrybridge. The sea was better covered than the land, with another 55 Common Scoter through off the Bill where up to 30 Manx Shearwaters and a Balearic Shearwater lingered offshore with a feeding flock of Gannets, gulls and Common Terns. What we thought had been the first Common Sandpiper of the autumn was heard calling over the Obs last night, but we've subsequently received a message from Nick Hopper with the results of his first overnight sound recording session of the season; Nick's list from overnight Monday into Tuesday (26th/27th) included 4 loggings of Common Sandpipers, a party of Knot, a Shelduck and Common Tern twice.

Persistent and at times quite heavy rain overnight led to a reduction in moth numbers in the traps but immigrants still featured quite strongly, with the chief prize being the island's first Orange-rayed Pearl Nascia cilialis at the Obs; further totals from there included 121 Diamond-back Moth, 30 Silver Y, 10 Rusty-dot Pearl, 9 Dark Sword Grass, 5 Bird-cherry Ermine and 2 each of Dark Pine Knot-horn and Rush Veneer.

As a rather localised inhabitant of fenland and marshes - mainly in East Anglia and southeast England - and evidently rarely exhibiting wanderlust, cilialis wasn't high up our list of likely additions to the moth list © Martin Cade:

28th June

Although the Common Rosefinch was still at Southwell the persistence of the day's rain meant that birding activities were severely limited and the only other worthwhile report was of 70 Swifts over the Bill.

The rain might have spoilt the birding but it was instrumental in dropping a fine arrival of immigrant moths, particularly at the Bill, where the overnight catch at the Obs was easily the best of the year to date and included 177 Diamond-back Moth, 27 Bird-cherry Ermine, 23 Cock's-head Bell Zeiraphera isertana, 20 Silver Y, 12 Dark Sword Grass, 8 Small Mottled Willow, 4 European Corn-borer, 4 Cream-bordered Green Pea, 3 Rush Veneer, 3 Double-lobed, 3 Dark Spectacle, 2 Large Beech Piercer Cydia fagiglandana, 2 Bullrush Veneer Calamotropha paludella, 2 Latticed Heath, 2 Pearly Underwing, 2 Small Marbled and singles of Waste Grass-veneer Pediasia contaminella, Warted Knot-horn Conobathra repandana, Dark Pine Knot-horn Dioryctia abietella, Tawny-barred Angle, Barred Red, Fen Wainscot and Red Admiral butterfly, with a couple of other potentially interesting micros still to confirm.  

Unfortunately we had too many other commitments today to be able to photograph many of the night's moths but this rather lovely green prasinaria form of the very infrequently-caught Barred Red was a first for the island © Martin Cade:


27th June

The promised rain held off until well towards midday allowing for some decent coverage. The Common Rosefinch showed up again at Southwell and provided the rarity interest but the day's list was otherwise full of signs of early autumn. Mediterranean Gull numbers have been building for a while and the first three figure total of the season was logged at Ferrybridge; at least 40 also passed through off the Bill, where 239 Common Scoter, 12 Manx Shearwaters, 3 Sandwich Terns, 2 Balearic Shearwaters and a Great Skua also made the tally. The land was relatively quiet, with singles of Lapwing and Chiffchaff the only arrivals at the Bill.

In lovely still conditions overnight moth-trapping was busy but immigrant numbers were inexplicably low, with a Small Marbled at the Grove the best of the oddities; a White Satin was a good island record at Weston.

Once a great rarity here, White Satin has become an almost expected oddity during periods of mid-summer immigration/dispersal © Duncan Walbridge/Martin Cade:

And we'd got behind with a few butterfly photos from the weekend; these mating Marbled Whites and Silver-studded Blues include a pair of the latter with a deformed female - fortunately, since their numbers look to be at a really low ebb this year, she seems to be making the best of getting the job done © Ken Dolbear:

26th June

Quieter, warm and sunny conditions made a welcome return but, at least in terms of new arrivals, it remained largely uneventful on the bird front. The long-staying but extremely elusive Common Rosefinch made just one appearance all day at Southwell when it showed up on a feeder during the evening. There were a handful of Swifts on the move over the Bill but most of what little was logged there was out to sea, with 46 Common Scoter, 13 Manx Shearwaters, 3 Mediterranean Gulls, a Balearic Shearwater and a Sandwich Tern through and a few feeding Common Terns lingering. The only other reports concerned 36 Mediterranean Gulls settled at Ferrybridge and 7 Little Egrets through overhead there.

A Dark Bordered Pearl Evergestis limbata trapped overnight at the Obs was a long awaited addition to the island moth list; other immigrant interest included 4 Small Mottled Willows and a Vestal at the Obs and singles of European Corn-borer and Small Mottled Willow at the Grove.

Assuming the Dark Bordered Pearl was a stray from the mainland rather than a primary immigrant it's taken the species more than 20 years to finally get here, with the first UK record now as long ago as 1994 © Martin Cade:

The discovery of a what amounts to an infestation of Lunar Hornet Clearwings in the Obs garden has been one of the more interesting events of the year and activity is ongoing, with plenty more sightings of adults including mating pairs during the last few days; in this little video clip from this morning it rather looks like the ?male was a less than willing partner © Martin Cade:

Mediterranean Gull and six of the seven Little Egrets at Ferrybridge this morning © Pete Saunders:

25th June

On a bright but still quite breezy day the only reports were of 3 Black-tailed Godwits at Ferrybridge and a surprise reappearance by the Common Rosefinch at Southwell.

Despite the stiff breeze moth numbers held up, with notable immigrants at the Obs in the form of a Scarce Light Plume Crombrugghia laetus and a Small Marbled.

The Scarce Light Plume © Martin Cade:

24th June

An important diary date for Obs members: this year's AGM will take at PBO at 7pm on Saturday 15th July; refreshments will be available after the meeting has concluded.
An agenda for the meeting can be viewed/printed here.

The first light rain for a while didn't perk up action on the land, with nothing of any note reported from the Bill. It was also disappointingly unproductive on the sea, with an at times pretty stiff breeze blowing in nothing more than 2 Balearic Shearwaters through off the Bill.

Small numbers of immigrant moths were logged, with 5 Small Mottled Willow, 2 Scarce Bordered Straw and a Vestal amongst the overnight catch at the Obs; elsewhere, 2 Small Mottled Willow, a European Corn-borer and a Vestal were trapped at the Grove.

With so little going on at the Bill we were tempted away to Weymouth to have a look at the Alpine Swift that had shown up at Lodmoor © Martin Cade:

On a more interesting matter we were very pleased to hear back from Professor Martin Collinson at the University of Aberdeen with news of our feather samples from the putative Greenish Warbler trapped at the Obs on 1st June; Martin reports that: 'The Greenish Warbler/possible Two-barred (KDV839, 01/06/17 - PV04) is confirmed as viridanus - it's 100% identical to viridanus individuals in the database, and 6% divergent from plumbeitarsus'. This came as something as a relief since we'd stuck our necks out and put the news out as Greenish Warbler and we likely wouldn't have been very popular if it had come back as a Two-barred Greenish! Since we're aware that there's been some serious questioning of the ID we may as well revisit the original photos and post a few extras of it at the same time © Martin Cade:

...and here's a longer version of the song/calls than we'd posted before:

Whilst the greater covert wingbar was certainly stronger than on other Greenish we've handled - and none of those had any trace of a median covert bar - in all other respects it had seemed to us that the bird was just too like a Greenish for it not to have been one - in particular, the song and calls sounded to be pretty typical Greenish, whilst plumage-wise the overall cold tone to the upperparts and the thin bridge of pale feathers over the base of the bill both favoured Greenish. We'd also urge caution when it comes to some of the supposedly pro-Two-barred Greenish features mentioned in the literature: the presence of small white tips to the inner webs of the greater coverts is patently unreliable since most of our Greenish have shown this; although it varied in prominence depending on the light, our bird showed an at times quite conspicuous pale yellow wash to the throat/upper breast; and Greenish can certainly show spotted ear-coverts, as evidenced by last year's individual (PBO, 18th June 2016 © Martin Cade):

23rd June

A very low-key day on the bird front with little more of interest than Manx Shearwaters on the move off the Bill: a few were trickling west through the morning, whilst a stronger eastbound movement of up to 200 per hour got going once the wind freshened during the afternoon.

With fresher conditions having set in moth numbers continued to dwindle but there were still hints of fresh immigrants arriving, with 2 Vestals and 2 Small Mottled Willows amongst the modest catch at the Obs and another Small Mottled Willow at Fortuneswell.

One of the more interesting events of this week has been the addition of Lunar Hornet Clearwing to the island moth list. We've already mentioned the discovery of the first adult that was found clinging to a mist-net in the Obs garden and further singles were found in the same circumstances both yesterday and this morning; it was pretty obvious that the species must be resident in the garden and it didn't take the ever enthusiastic Andy Dyball long to discover signs of larval feeding, an exited pupal case and finally another adult on at least three sallow trees there. The pencil-width pupal exit holes - several with scatterings of sawdust underneath - were quickly spotted up to about a metre off the ground, and it wasn't long before one was found with an exited pupal case at its entrance:

...two adults, with a pupal case just to the right of the lower insect:

...Andy photographing an adult on one of the trees photos © Martin Cade:

Also on the clearwing front, Six-belted Clearwings are now on the wing quite plentifully, this one came to a pheromone lure yesterday at Inmosthay © Ken Dolbear:

...and a bit of an oddity in the butterfly line, this aberrant female Silver-studded Blue was at Tout Quarry © Ken Dolbear:

22nd June

A reminder that there's an In Focus field event at the Obs between 10am and 4pm this Saturday, 24th June.

In much fresher and breezier conditions than of late the Common Rosefinch remained at Southwell but was seemingly always hidden from general view in private gardens. The change in the weather didn't really perk things up on the land at the Bill, with another 90 Swifts and a Grey Heron through overhead and another new Chiffchaff at the Obs the only reports of note. Offshore, at least 30 Common Terns off the Bill were presumed to be Lodmoor breeders on feeding forays; 7 Manx Shearwaters, 7 Mediterranean Gulls, 2 Common Scoter and a Whimbrel also passed through/lingered there. The only reports from elsewhere were of up to 10 Mediterranean Gulls and 4 Sandwich Terns at Ferrybridge.

Overnight mothing was not quite as busy as in recent nights with fog and a freshening breeze pegging back numbers, but there signs of a small arrival of new immigrants/dispersers. At the Obs, a Marbled Grass-veneer Catoptria verellus was the immigrant highlight, with 6 Diamond-back Moth, 4 Rusty-dot Pearl, 3 each of European Corn-borer and Silver Y, 2 each of Rush Veneer and Dark Sword Grass, and singles of Olive-tree Pearl, Hummingbird Hawkmoth, Small Mottled Willow and Scarce Bordered Straw making up the rest of the tally.

The Common Rosefinch lingered on but was mobile and generally elusive - it very occasionally gave some half-hearted song and was only seen when it visited various birder's back gardens © Pete Saunders:

...we made an early morning attempt to sound record it during which time it only called/sung twice in an hour:

From the evidence of the national records it would seem as though Marbled Grass-veneer might be in the process of colonising south-east England, but it remains a decent rarity in this part of the world - last night's specimen constituted only the second island record © Martin Cade:

21st June

Yesterday's Common Rosefinch remained overnight at Southwell to provide a nice mid-summer highlight: after announcing its presence with strident song for a while at dawn it became a good deal more furtive as the day went on and was never visible other in private gardens. Also in the finch line, a Siskin was an odd summer turn up at the Bill, but the day had few other surprises, with another new Chiffchaff at the Bill, 70 Swifts and 3 Sand Martins through overhead there and 18 Common Scoter, 8 Mediterranean Gulls, 5 Black-headed Gulls and 3 Manx Shearwaters through/lingering offshore.

Despite the continuing high temperatures immigrant moth activity remained quite subdued, with 29 Diamond-back Moth, 11 Silver Y, 3 Rusty-dot Pearl, 2 Rush Veneer and an Olive-tree Pearl making up the totals at the Obs.

Although the rosefinch showed well at times - usually when it visited feeders - it quickly sung much more fitfully after its noisy start and we weren't able to get a sound recording of it © Debby Saunders (stills) and Martin Cade (video):

It'll be interesting to see if this unseasonable Siskin wandering out as far as the Bill proves to the vanguard of a strong autumn passage - are they on the move elsewhere yet? © Martin Cade:

20th June

With a fresher easterly breeze beginning to set in conditions were a little more conducive for fieldwork and there were a couple of surprises to show for the day's efforts. With the month slipping away it was looking like Common Rosefinch - perhaps the classic Portland June rarity - might be a no-show this year so a brief spell of song from one hidden in the depths of the Southwell gardens during the afternoon was welcome even if the bird couldn't be seen. For the most part the rewards from the sea at the Bill - 10 Manx Shearwaters, 7 Common Scoter, 2 Balearic Shearwaters, 2 Mediterranean Gulls and a Sandwich Tern - were to be expected, but the 2 fly-by Red-breasted Mergansers there were much less seasonable. The day's other reports included 70 Swifts and 4 Sand Martins through over the Bill and 3 new Chiffchaffs and a new Blackcap at the Obs.

Overnight moth-trapping was very busy indeed; immigrant activity was still quite limited but there was much more evidence of short-range dispersal than in recent nights. Immigrant totals at the Obs included 27 Diamond-back Moth, 6 Silver Y, 5 Rusty-dot Pearl and singles of Rush Veneer, Olive-tree Pearl and European Corn-borer, with further singles of Olive-tree Pearl and European Corn-borer at the Grove.

Auks below their breeding ledges at the Bill today © Roger Hewitt:

Having spent the last three nights on miscellaneous mothing forays around the island and elsewhere we've got behind with updates. The moth highlight has been Portland's first Lunar Hornet Clearwing that was found clinging to a recently opened mist-net at the Obs shortly after dawn yesterday; over the years we've had a couple of subliminal glimpses of insects that we felt sure must have been one of other of the hornet clearwings so yesterday's record was very welcome in finally providing confirmation of Lunar Hornet - presumably by far the more likely of the two species to occur here © Martin Cade: 

19th June

There's limited enthusiasm for comprehensive fieldwork in the current hot weather but a few odds and ends did make the day's list. Early leavers over the Bill included 30 more Swifts, 2 more Sand Martins (we hadn't been told of the first single two days ago when we compiled the update for that day) and a Redshank; sea passage there included 34 Common Scoter, 6 Manx Shearwaters, 4 Whimbrel and 3 Mediterranean Gulls. The only other reports were of a Black Redstart at Blacknor (there's been a series of singles between the Bill and Blacknor this summer - could they be breeding somewhere on the west side?) and the first juvenile Chiffchaff at the Bill (presumably a dispersing local breeder).

Moth news to follow tomorrow.

18th June

Very hot and none too exciting again today. The only reports from the Bill were from the sea, where 53 Common Scoter, 3 Whimbrel, a Manx Shearwater and a Common Tern passed through; elsewhere, 7 Sandwich Terns passed through Ferrybridge where 5 Mediterranean Gulls were settled.

Sandwich Terns over Ferrybridge © Pete Saunders:

Although they've been on the wing for several weeks on the mainland, Portland Lulworth Skippers seem usually to be late emergers; our first record for the year was only yesterday, with this one at Broadcroft BC Reserve today © Ken Dolbear: 

There are some great displays of Pyramidal Orchids throughout the island at the moment - these were also at Broadcroft © Ken Dolbear:

17th June

Extremely little to show for today's fieldwork that was pretty hard going in the scorching heat. A Yellow Wagtail at the Bill and 2 Sanderling at Ferrybridge were the day's only worthwhile sightings.

The moth-traps were bursting with numbers but quality was lacking: singles of Olive-tree Pearl at the Obs and Delicate at the Grove were easily the best of a limited selection of immigrants.

Bird interest might be limited but the island is certainly awash with bugs; among the random selection attracting the photographer's attention were a Marbled White at the Bill © Debby Saunders:

...and at Admiralty Quarry, mating Silver-studded Blues, a Cinnabar Moth and a Mullein caterpillar feeding on Common Figwort (the other insect in this photo is evidently a Figwort Weevil Cionus scrophulariae) © Ken Dolbear:

16th June

The fine, warm weather continued and there were precious few signs that the summer rarity was about to pop up. Two new Chiffchaffs at the Obs looked to be early departers as were the light trickle of Swifts and single House Martin heading out to sea overhead. Two each of Sanderling and Dunlin made up the migrant wader tally at Ferrybridge, where 2 Shelducks also dropped in. The only other reports were of 10 Manx Shearwaters through off the Bill and a lone Gannet in Portland Harbour.

Usually at this time of year we have a quick look back at how common migrants fared during the spring and, as before, it's easiest to gauge this by way of the Obs ringing totals that are based on a pretty consistent effort from one year to the next; these totals - together with comparison figures for 2010-16 and the mean for that period - were as follows:

As we'd drawn attention to earlier, it's immediately obvious that Willow Warbler was the big winner this spring with a total nearly twice as high as the recent spring average; in fact, their total wasn't far off equalling the all-time record for a whole year (which stands at 2113 in 2012). For our other regulars it really wasn't too bad a season: both Whitethroat and Garden Warbler were more than a third down on their recent averages (...this perhaps didn't come as a surprise given that both had very poor years in 2016) and the two 'crests didn't recover after their indifferent showings last autumn, but everything else was hovering either side of average.

Sanderling and Shelducks at Ferrybridge this morning © Pete Saunders:

...a Gannet off the Bill © Martin Cade:

...and a Hornet Hoverfly Volucella zonaria at Bottomcombe © Ken Dolbear: