16th August

Despite the first substantial rainfall in several months and heavily overcast skies for the best part of the day it seems that all vectors of passerine migration remain headed well away from Portland and it was left to waders and gulls to give some degree of respectability to the day's proceedings, with huge increases in Ringed Plover and Black-headed Gull of particular note. Overnight moth-trapping was also crushingly duff in conditions that had looked perfect for both immigration and trapping.

Portland Bill
Grounded migrants Wheatear 15, Willow Warbler 10, Sedge Warbler 5, Turnstone 2, Garden Warbler 2, Great Spotted Woodpecker 1, Whinchat 1, Pied Flycatcher 1, Spotted Flycatcher 1.
Visible passage Grey Plover 8, Ringed Plover 2, Common Sandpiper 2, Dunlin 1, Whimbrel 1, Turnstone 1.
Sea passage Black-headed Gull 378e, Mediterranean Gull 60, Balearic Shearwater 54, commic tern 14w, Common Scoter 9w 1e, Sandwich Tern 7w, Arctic Skua 2w; also Bluefin Tuna 2.

Ringed Plover 306, Dunlin 112, Sanderling 6, Grey Plover 1, Knot 1, Redshank 1, Wood Sandpiper 1, Arctic Tern 1.

Portland Harbour
Little Gull 1.

Selected immigrants Obs: Rush Veneer 63, Diamond-back 43, Rusty-dot Pearl 33, Dark Sword Grass 8, Silver Y 6, Glasswort Case-bearer 3, Spindle Knot-horn 2, Bordered Straw 2, Brown Knot-horn Matilella fusca 1, also Migrant Hawker dragonfly 1. 

Always a tricky bird to catch up with at Portland, this morning's Wood Sandpiper even obliged by settling at Ferrybridge...

...where a nicely-plumaged Grey Plover was another decent wader downed by the rain © Pete Saunders:

Late in the day a Little Gull was an unexpected bonus amongst the ubiquitous Mediterranean Gulls at Portland Harbour © Martin Cade:

15th August

Any hopes that the hot weather would end with a migrant bonanza as Atlantic-influenced conditions begun to make headway were dashed in the early hours when fog rolled in and blanketed the island until well into the morning. Any passing migrants were likely oblivious to Portland's existence and were it not for a conspicuous influx of immigrant moths the day would have passed off quietly.

The Obs barely visible from the Crown Estate Field: today wasn't to be one of those rare days when fog dropped migrants in quantity © Martin Cade:

Portland Bill
Grounded migrants Willow Warbler 30, Wheatear 10, Whitethroat 10, Sedge Warbler 8, Pied Flycatcher 2, Garden Warbler 1.
Visible passage Tree Pipit 4, Ringed Plover 2, Hobby 1, Dunlin 1.
Sea passage Lesser Black-backed Gull 12s, Kittiwake 7e, Balearic Shearwater 2e 3w, Common Scoter 2w, Arctic Skua 2, Shelduck 1, Yellow-legged Gull 1; also Harbour Porpoise 2, Bluefin Tuna 1.

Ringed Plover 103, Dunlin 60, Sanderling 3, Curlew 3, Knot 1, Whimbrel 1, Redshank 1.

Selected immigrants Obs: Diamond-back 248, Rush Veneer 70, Rusty-dot Pearl 26, Glasswort Case-bearer Coleophora salicorniae 12, Dark Sword Grass 7, Spindle Knot-horn 3, Silver Y 2, Chamomile Conch Cochylidia implicitana 1, Bulrush Veneer Calamotropha paludella 1, Narrow-winged Pug 1, Hummingbird Hawkmoth 1, Pearly Underwing 1, Shining Marbled 1, Small Marbled 1. Easton: Olive-tree Pearl 1. Grove: European Corn-borer 1, Dark Spinach 1, Painted Lady 1, Bordered Straw 1, Scarce Bordered Straw 1.

Portland's second Shining Marbled - the first was way back on 26th August 2013 - was the night's immigrant highlight; it's still a decent quality moth with just 22 British records up to the end of last year © Martin Cade:

14th August

On what's being reported to be probably the last day of the recent eastward-influenced heatwave the temperature soared to an unofficial (...this writer's car thermometer!) 30°C by the afternoon. With the moon still sizeable in the clear night sky grounded migrant numbers remained very low and, more surprisingly, diurnal visible passage was almost non-existent with the first Hobby of the autumn the only minor highlight. Offshore, Balearic Shearwaters disappeared from visible range but Lesser Black-backed Gull passage gained some momentum.

Portland Bill
Grounded migrants Wheatear 50, Willow Warbler 30, Sedge Warbler 10, Whinchat 3, Blackcap 2, Pied Flycatcher 1, Spotted Flycatcher 1.
Visible passage Swallow 25, Sand Martin 20, Swift 10, Ringed Plover 1, Tree Pipit 1.
Sea passage Mediterranean Gull 100etc, Black-headed Gull 100etc, Lesser Black-backed Gull 40s 30etc, Common Scoter 2e, Balearic Shearwater 1w, Common Gull 1w, Sandwich Tern 1w.

Pied Flycatcher 1.

Barleycrates Lane
Whinchat 1.

Dunlin 96, Ringed Plover 70, Sandwich Tern 5, Sanderling 3, Black-tailed Godwit 1, Knot 1, Redshank 1, Hobby 1s.

Selected immigrants Obs: Diamond-back 47, Rush Veneer 16, Rusty-dot Pearl 15, Dark Sword Grass 11, Silver 4, Spindle Knot-horn 3, Tree-lichen Beauty 2, Roseate Marble Celypha rosaceana 1, Peacock 1, Bordered Straw 1, Scarce Bordered Straw 1. Grove: Jersey Mocha 1.

Amid the general doom and gloom about birds being fewer than they used to be Black-tailed Godwit is one thing that's logged far more frequently at Portland these days than it used to be. Our records have thus far all been of the Icelandic subspecies which is doing considerably better than the declining Continental subspecies © Pete Saunders:

In amongst the various rarer immigrants a moth we were really pleased to catch overnight at the Obs was this Peacock. Having only recently trapped plenty of Peacocks in northern France we'd been reminded just how blindingly obvious the genuine article is when we're used to seeing only Sharp-angled Peacocks at Portland. Peacock has a bit of a chequered history here with only one fully confirmed record for the island although there are probably one or two others that currently languish as collected specimens that haven't been revisited; oddly, at least one further specimen that had been 'confirmed' by several usually reliable consultees proved on dissection to be a Sharp-angled Peacock! © Martin Cade:

13th August

Portland Bill
Grounded migrants Wheatear 70, Willow Warbler 20, Sedge Warbler 5, Yellow-legged Gull 1, Whinchat 1, Grasshopper Warbler 1, Reed Warbler 1, Spotted Flycatcher 1.
Visible passage Sand Martin 40, Dunlin 4e. 
Sea passage Mediterranean Gull 200w, Black-headed Gull 56w, 6e, Lesser Black-backed Gull c50etc, Balearic Shearwater 20etc, Common Scoter 2e, Sooty Shearwater 1w; also Bottle-nosed Dolphin c8etc.

Pied Flycatcher 1. 

Whinchat 2, Spotted Flycatcher 1.

Little Tern 3, Sanderling 2, Knot 1.

Selected immigrants Obs: Diamond-back 43, Rush Veneer 15, Rusty-dot Pearl 11, Dark Sword Grass 9, Saltmarsh Knot-horn 3, Silver Y 3, Tufted Button Acleris cristana 1, Spindle Knot-horn 1, Beautiful Marbled 1, Bordered Straw 1. Grove: Saltmarsh Knot-horn 2, Spindle Knot-horn 2.

12th August

Portland Bill
Grounded migrants Wheatear 30, Willow Warbler 20, Sedge Warbler 6, Pied Flycatcher 2, Spotted Flycatcher 1.
Visible passage Swallow 100, Sand Martin 40, Little Egret 2, Yellow Wagtail 1.
Sea passage Mediterranean Gull 500w, Black-headed Gull 55w, Balearic Shearwater 40w 11etc, Lesser Black-backed Gull 19s, Common Gull 3w ,Sandwich Tern 2w, Common Scoter 1w, Whimbrel 1e; also Bluefin Tuna 1etc.

Pied Flycatcher 1.

Selected immigrants Obs: Diamond-back 19, Dark Sword Grass 11, Rusty-dot Pearl 9, Rush Veneer 8, Spindle Knot-horn 3, Vagrant Piercer Cydia amplana 1, Saltmarsh Knot-horn 1, Small Marbled 1, Silver Y 1. Weston: Saltmarsh Knot-horn 1. Blacknor: Saltmarsh Knot-horn 1.

We renewed our acquaintance with an old friend today when this Sedge Warbler popped up in a mist-net in the Crown Estate Field; the ring number looked familiar and it turned out to be a bird ringed here as a youngster on outbound passage on 18th September last year. That date's getting pretty late in the season for a Sedge Warbler (last year only 11 of the autumn's all-time record total of c350 were ringed after this bird) but this bird clearly made it to its winter quarters and returned - presumably to Britain - again this year; it's also got tardiness out of its system since, if we had a check of the data, we wouldn't mind betting that this year's departure date of 12th August must be very close to our median date for autumn Sedge Warblers © Martin Cade:

Immigrant-wise, mothing in the recent blistering heat has been a little lame, but there has been a fair bit of local movement afoot. Cabbage Piercer Selania leplastriana is extremely range-restricted in Britain although easy enough to find amongst Wild Cabbage on West Cliffs at Portland - today's single at the Obs was one of very few to ever make it into the moth-traps there:

Eyed Bell Eucosma pupillana and Starry Pearl Cynaeda dentalis are also both very range-restricted specialities of Portland that are straightforward to find in the vicinity of their larval foodplants - Wormwood and Viper's Bugloss respectively - but rarely stray far away from them:

For us, the best capture in recent nights has been this Roseate Marble Celypha rosaceana; although reported to be 'occasionally common' in the Victorian era we have no evidence of it being anything other than a very infrequent stray/immigrant to the island in modern times © Martin Cade:

11th August

Portland Bill
Grounded migrants Wheatear 30, Willow Warbler 15, Sedge Warbler 5, Whinchat 1, Lesser Whitethroat 1, Spotted Flycatcher 1.
Visible passage Sand Martin 160e, Swallow 100e, Redshank 2, Tree Pipit 2, Whimbrel 1.
Sea passage Mediterranean Gull 400w, Balearic Shearwater 155e 10w, Black-headed Gull 13, Common Scoter 1w, Common Gull 1e, Sandwich Tern 1w; also Bluefin Tuna several offshore.

Pied Flycatcher 1.

Selected immigrants Obs: Rusty-dot Pearl 7, Rush Veneer 6, Dark Sword Grass 5, Diamond-back Moth 3, Tree-lichen Beauty 2, Wax Moth G. mellonella 1, Spindle Knot-horn N. angustella 1, Saltmarsh Knot-horn A. oblitella 1, Silver Y 1 + Red Admiral butterfly 1.

The Sweethill Pied Flycatcher © Debby Saunders:

10th August

Portland Bill
Grounded migrants Wheatear 40, Willow Warbler 20, Sedge Warbler 5, Pied Flycatcher 2, Yellow-legged Gull 1, Blackcap 1, Garden Warbler 1.
Visible passage Swallow 200e, Sand Martin 180e, Redshank 1.
Sea passage Balearic Shearwater 60e, Common Scoter 5w 3e, Lesser Black-backed Gull 14s, Sandwich Tern 3e, Teal 2e, Arctic Skua 2e.

Mediterranean Gull c1000, Sanderling 2, Knot 1, Whimbrel 1, Redshank 1.

Selected immigrants Obs: Rush Veneer 18, Rusty-dot Pearl 10, Dark Sword Grass 7, Pearly Underwing 3, Diamond-back Moth 1, Silver Y 1, Small Mottled Willow 1; Grove: Lesser-spotted Pinion 1, Saltmarsh Knot-horn A. oblitella 1.

This morning's Whimbrel at Ferrybridge © Pete Saunders:

Spot the differences between the two Sedge Warbler age classes at this time of year - the adults have been wearing the same set of feathers for ten months or so (...and won't moult them until they get to Africa) whereas the youngsters are more or less mint fresh © Martin Cade:

Saltmarsh Knot-horn Ancylosis oblitella is an occasional stray in the moth-traps at this time of year, often during spells of hot easterly weather; far from annual here and presumably originating from southeast England or the near Continent, they tend to arrive in little influxes so the singles yesterday and today at the Obs and the Grove respectively may prove to be the precursors of a few more © Martin Cade:

9th August

Portland Bill
Grounded migrants Willow Warbler 20, Wheatears 10, Sedge Warbler 10, Whitethroat 10, Garden Warbler 2, Tree Pipit 1, Reed Warbler 1, Blackcaps 1, Pied Flycatcher 1, 
Visible passage Swallow 250, Sand Martin 25, Swift 7.
Sea passage Mediterranean Gull c100 w/etc, Balearic Shearwater 10e 8w, Manx Shearwater 3e, Common Scoter 1w.

Tout Quarry
Pied Flycatcher 1.

Dunlin 118, Ringed Plover 62, Sanderling 7, Curlew 4, Little Tern 3, Knot 1.

Selected immigrants Obs Rush Veneer 35, Rusty-dot Pearl 20, Silver Y 6, Dark Sword Grass 6, Bordered Straw 1, Pearly Underwing 1, Small Mottled Willow 1, Saltmarsh Knot-horn Ancylosis oblitella 1; Grove Convolvulus Hawkmoth 1.

8th August

With the heat continuing to build there was ample reason not to dwell in the field through the middle of the day but early and late coverage revealed a fair bit of variety if nothing in quantity. A seawatch fly-by Stone Curlew was an exciting and bizarre little event at the Bill where some egret movement saw 2 Cattle Egrets and 4 Little Egrets arrive in off the sea. The light scatter of grounded migrants was dominated by the usual quartet of Wheatear, Sedge Warbler, Whitethroat  and Willow Warbler, with the odd singletons including a Garden Warbler and a Lesser Whitethroat at the Bill and a Pied Flycatcher at Tout Quarry; Ferrybridge was busier with a largely unchanged tally of waders that included singles of Knot and Redshank. The sea totals included 10 Balearic Shearwaters and an Arctic Skua through off the Bill.

Overnight moth-trapping was a little more productive for immigrants that included a Dark Crimson Underwing at the Obs and a Convolvulus Hawkmoth at the Higher Light.

7th August

With no end in sight to the dry, scorching conditions it was no great surprise that today didn't come up with numbers even if it wasn't too bad on the variety front. The modest arrival of 25 apiece of Wheatear and Willow Warbler at the Bill was accompanied by a few Sedge Warblers and singles of Tree Pipit, Reed Warbler, Garden Warbler, Lesser Whitethroat and Spotted Flycatcher, whilst overhead there was a light passage of hirundines along with the likes of 2 Dunlin and a Little Ringed Plover; the wader theme also saw a small increase into a three figure total of Dunlin at Ferrybridge, singles of Knot and Bar-tailed Godwit new there and 2 Turnstones and a Whimbrel through off the Bill. Mediterranean Gulls continued to make up the bulk of the moving numbers offshore with 200 through off the Bill, where 7 Balearic Shearwaters and a Yellow-legged Gull also passed by.

Two Scarce Bordered Straw and a Bordered Straw were the best of the immigrant moths at the Obs where a small arrival of 4 Crescents was also of note.

Knot and Bar-tailed Godwit looking dazzling amongst the waders at Ferrybridge today; it's so easy to take them for granted and forget the backstory that in the three months since we last saw their kind in this plumage on the sandflats at Ferrybridge they've likely been right up to the Russian Arctic tundra and back © Martin Cade:

The Southwell Barn Owls continue to perform nicely © Pete Saunders:

6th August

Hot, sunny and hardly bird-filled today. With the conditions far too benign to drop passerines in quantity it was hard work on the ground at the Bill, where the light scatter of routine warblers and Wheatears included in their midst just a lone Garden Warbler of minor note. Waders were a little better represented, with 125 Ringed Plovers, 83 Dunlin, 14 Sanderling and 4 Redshank making up the bulk of the tally at Ferrybridge. Visible passage was poorly covered but included a steady passage of Sand Martins everywhere and a gathering of 30 Swifts over Weston.

The clear sky and cool, brisky breeze did little for overnight mothing, with singles of Cosmopolitan and Bordered Straw as good as it got amongst the immigrants at the Obs.

We mentioned a couple of days ago the occasional paler Willow Warblers - at this time of year most likely nearly all 'just' adults rather than birds of more distant origin - amongst all the dazzling youngsters and the capture of one of these adults afforded the opportunity to have a closer look at it (in these pairs of photos the adult is at the top and the youngster at the bottom). The underparts are conspicuously more silky-white, with just a wash of pale yellow on the throat and under tail coverts; in contrast the youngsters are yellow to a varying degree across the whole of their underparts. Note also the much broader pale tips to the primaries in the adult:

Adults have noticeably broader, more round-ended tail feathers than youngsters; notice also how the better quality feathers in the adult tail are showing hardly any signs of wear, whereas the poorer quality feathers of the youngster are already beginning to get chipped and frayed at the tips. As usual, a note of caution: ageing's straightforward when the differences are as obvious as they are in our examples here but plenty of tricky intermediates crop up that aren't nearly so easy and these are always best left un-aged! © Martin Cade:

Finally, sad news to convey of the death last week of Nick Wright. 

Nick moved to Dorset in 2003 after a career as a Royal Air Force officer and, after retirement, spells in university and school administration. His interest in natural history - as a youngster in the early 1960s he'd had a spell as a long-term volunteer at Bardsey Bird Observatory - led him to gravitate toward PBO where he served as our Honorary Secretary between 2007 and 2012; many members and visitors will perhaps have known him best during this period for also managing our Bookshop. In mid-life Nick had been struck down literally overnight by a profound disability that severely impacted his mobility but he always made light of this and resolved to make as much of the rest of his life as he could - a resolution that he certainly fulfilled. He maintained the affairs of both his secretaryship and the bookshop in the most meticulous of fashions and was always willing to assist his successor. Nick did much good work for the Obs for which we're extremely grateful and we offer our sincere condolences to his family.

A couple of yesterday's flight shots of showing comparison with the Dunlin the Ferrybridge White-rumped Sandpiper pic.twitter.com/I2ImWkULg5

5th August

The presence of a good-sized, making moon in the clear night sky had been reasoned to be beneficial on the hitherto quiet wader front but today's variety in that line came as quite a surprise, with the star of the show the island's fourth White-rumped Sandpiper that showed up at Ferrybridge; 2 Little Ringed Plovers there and singles of Snipe and Green Sandpiper at the Bill were also additions to the varied tally of more routine fare. Passerines weren't to be outdone, with another flurry of 70 Willow Warblers and 20 Sedge Warblers at the Bill being joined by the likes of singles of Tree Pipit and Spotted Flycatcher on the ground and a trickle of Sand Martins and a few extra House Martins overhead. Three Balearic Shearwaters and an Arctic Skua were as good as it got on the sea at the Bill.

The first Convolvulus Hawkmoth of the year was easily the pick of an otherwise very limited selection of immigrant moths at the Obs.

The White-rumped Sandpiper at Ferrybridge © Pete Saunders (flight), Keith Pritchard (settled) and Martin Cade (video):

The morning's two Little Ringed Plovers at Ferrybridge © Pete Saunders...

...and the Snipe and Green Sandpiper over the Bill © Martin Cade:

The next week or so ought to see autumn Sedge Warbler passage reach its peak - at the rate things are going there'll need to be a massive perking up in numbers for the season's total to reach even faint respectability, let alone get close to matching last year's record © Martin Cade:

First Convolvulus Hawk of the year from the Obs moth-traps this mrng pic.twitter.com/sieeXUxERO

4th August

With the murky conditions of the last couple of days well and truly cleared away by the passing of the weakest of weather fronts clear skies were the order of both the night and the day. Migrants were afforded the opportunity to make onward progress and a fair number paused at least briefly at the Bill, where 100 Willow Warblers and 30 Sedge Warblers made up the bulk of the the totals accrued from woefully inadequate coverage; a Garden Warbler and a handful of Wheatears were also logged, with 10 Sanderling the best amongst the grounded wader selection at Ferrybridge. Overhead passage wasn't as conspicuous as might have been hoped: a Honey Buzzard over Easton was the stand-out highlight, with the few pulses of hirundines through at the Bill hardly amounting to a concerted passage. Sea movement was limited but did include 4 Balearic Shearwaters, 2 Yellow-legged Gulls and a Black-tailed Godwit through off the Bill.

The clearer, fresher conditions did no favours for overnight moth-trapping, with a lone Porter's Rustic - the third of the season and the 27th record for the island - the immigrant highlight at the Obs.

The vast majority of the day's little flurry of Willow Warblers were dazzling youngsters...

...but amongst them were a few - likely mostly adults - of more subdued saturation.

Adult Linnets are looking far from their best right now - this female was right in the middle of its post-breeding moult with its still unmoulted outer primaries showing all the signs of being a year old...

...in contrast, this year's juveniles are looking really dapper with their altogether more subtle body moult not taking its toll on their looks:

For whatever reason - was it the little bit of moisture in the air at times yesterday? - there was a good hatch of flying ants this evening that in turn attracted lots of gulls; around the top of the island large gulls were to the fore but along the Beach Road and at Ferrybridge many hundreds of Mediterranean Gulls - looking really spectacular against the clear, blue sky - made up the bulk of the feeding frenzy:

Despite being a rewarding season for a range of immigrant lepidoptera this summer hasn't been much cop for Clouded Yellows so it was nice to see two lingering beside the pathways in the Crown Estate Field this morning: 

Porter's Rustic is hardly one of the most inspiring scarcities and such is its anonymity that it's surprisingly easy to overlook in a busy moth-trap - we've done it ourselves! However, once seen/learnt it does have a look all to itself...

...here's today's specimen with a Small Rufous, one of the many other species that could be construed to bear some passing resemblance to Porter's Rustic photos © Martin Cade: