31st August

Although abject on the migrant front today was saved by some more unexpected happenings on the sea. It was Manx Shearwaters that again made up all the numbers, with several pulses of many hundreds in quick time passing through off the Bill, with it looking like yesterday's total of c3000 may well have been reached again; Balearic Shearwaters featured a little more conspicuously, with at least 36 through, whilst further interest came in the form of singles of Sooty Shearwater and Arctic Skua. A Goshawk heading north at the Grove was a surprise but, common migrant-wise, it was a dreadful day with only Wheatear getting beyond a double figure total on the ground at the Bill.

As we mentioned last evening, Nick Hopper had a couple of good nocturnal recording sessions when he was staying with us last weekend; Tree Pipits dominated but the totals of Robin and Pied Flycatcher were also the best recorded to date - the combined totals for the nights of 24th/25th and 25th/26th were:

Tree Pipit calls 1122
Robin calls 161
Pied Flycatcher 47
Spotted Flycatcher 3
Yellow Wagtail 18
Little Ringed Plover
Green Sandpiper 4+
Greenshank 1
Turnstone 1
Redshank 5+
Common Sandpiper 6+
Knot 4 flocks
Dunlin 5 flocks
Ringed Plover 8 flocks
Common Tern 2 flocks
Grey Heron 2

30th August

Although dawn had seen more cloud in the sky than had been expected this soon cleared and the day was for the most part bright and breezy, as well as being really quite warm by the afternoon. The day's oddest event was an extraordinarily strong - but very short and sharp since it lasted for less than an hour - eastward movement of c3000 Manx Shearwaters off the Bill midway through the morning; the sea otherwise produced little more than 20 Balearic Shearwaters and a lone Great Skua. The land was the quietest it had been all week, with routine passage restricted to barely more than double figure totals of even the commonest migrants; 3 each of White Wagtail and Grasshopper Warbler was about as good as it got at the Bill, with a single Pied Flycatcher at Thumb Lane the only other worthwhile sighting. Finally, apologies to Nick Hopper who worked really hard to collate a report for us from a couple of really busy night's of nocturnal recording earlier this week; we've been so pushed for time since then that we still haven't been able to upload any of this to the blog - hopefully tomorrow!

We don't log/trap anything like the numbers of Grasshopper Warblers that are recorded at some spots along the south coast but by our standards this autumn has been a good one for the species: the three trapped today take our autumn ringing total to 17 which we think is the highest ever (our record annual total is only 21); since we don't target Grasshopper Warbler with, for example, pre-dawn sound lures it seems like there's been a much stronger than usual passage through the island this year © John Martin:

29th August


A reminder that there's an In Focus field event at the Obs between 10am and 4pm this Saturday, 31st August.

Just a brief update as we're a bit pushed for time this evening. A quieter day for numbers with the freshening southwesterly and clear skies that arrived in the wake of last evening's drizzly rain seeing many migrants - particularly the bulk of the Yellow Wagtails - move on. A Wryneck trapped in the Crown Estate Field was the best of the day's newcomers.

The fifth Passenger for Portland from the Obs traps was the pick of the night's moth catch.

The Wryneck © Martin Cade/Erin Taylor...

...and the Passenger © Martin Cade:

28th August

The surge in migration that materialised over the Bank Holiday weekend lost more momentum today but there was still plenty enough on offer around the island even if scarcities remained doggedly absent or undiscovered. Wheatear and Yellow Wagtail remained the most conspicuous species, with 100 or more of each at the Bill alone, whilst among the varied collection of back-ups in lower numbers 3 White Wagtails, a Green Sandpiper and a Firecrest at the Bill were of note. A trickle of passage at sea included 3 Balearic Shearwaters and singles of Arctic Skua and Yellow-legged Gull through off the Bill.

We find it hard to believe there isn't a Wryneck or two lurking somewhere on the island but some pretty conscientious legwork failed to uncover anything out of the ordinary today. We could add that a lot of fieldwork yesterday failed to turn up any sign of this very vocal and very mobile Budgerigar at any time other than for the few minutes it was present in the Obs garden - how did it escape attention for the rest of the day? We also received a message yesterday reporting 'the' flock of 20 released White Storks that had evidently been settled on Chesil Beach close to the island boundary for a considerable time last Saturday morning; although they were spotted later over Abbotsbury it seems their sojourn in the Weymouth area completely escaped the attention of any 'mainstream' birders - these sort of events really do make you wonder how much we're missing! © Martin Cade:

Although absolutely nothing to do with natural history, our highlight of today was the sight of this faintly sinister-looking B52 bomber right over the Obs just after dawn - having spent a chunk of our childhood goggle-eyed at TV footage of these things napalming Vietnam is was oddly surreal to finally see one 'in the flesh' and still in military service getting on for 50 years later © Martin Cade:

27th August

A slight anti-climax compared to recent days but there was still plenty of action to keep us on our toes all day. A mystery bird with an unidentified call finally materialised into the bird of the day- a rather smart blue and yellow Budgie in the obs garden. A close contender for the best bird was the first Firecrest of the autumn, a young male that blundered into a net in the early morning. With the exception of these two events the day tally was much as we'd expect given the past few days, Yellow Wagtails continued to be the most conspicuous migrant and Wheatears maintained a steady stream throughout the day. The flycatcher passage recommenced with a whole island count of 12 Pied Flycatchers and six Spotted Flycatchers. One Pied Flycatcher retrapped in the garden was ringed five days ago and has gained over 5g since its initial capture and now weighs a whopping 17.6g. Whinchats were down on yesterday but still reached a respectable 11 across the obs area, the decline was also noticeable in Tree Pipits where only 5 were trapped of a much reduced flock within the crown fields. Other singles included an Osprey fishing in the harbour, a fly-by Greenshank and a Reed Warbler in the crown fields.

There were plenty of nice migrant photo opportunities today; Wheatear and Whinchat © Tim Downton...

...Redstart © Debby Saunders...

...Yellow Wagtail and Spotted Flycatcher © Nick Stantiford:

And some of the locals were showing nicely - Little Owl and Stonechat © Tim Downton:

26th August

Where do we begin today? A day of quantity over quality, but as they say quantity has a quality of its own. The first real autumn fall of the year with 114 birds ringed across all sights including 51 Willow Warblers. Following on from the recent theme Yellow Wagtails were the most conspicuous species with 175 around the Bill area alone and 250+ across the whole island. Tree Pipits continued to move and 50 were recorded within the obs area. Wheatears and Whinchats were also visibly moving through throughout the day with 150 and 20 respectively. Across the island there was a noticeable increase in flycatchers with an island total of 27 Pied Flycatchers and 14 Spotted Flycatchers. Other migrants of note included a pair of Redstarts (including one trapped in the garden), 12 White Wagtails amongst the feeding flocks of Yellow Wagtails, a Marsh Harrier heading south down the East side of the island and the first Water Rail trapped of the autumn.

Ferrybridge continued its streak with high counts of the regular migrants as well as a flock of 8 Knot and a very smart looking Little Gull ©Debby Saunders:

25th August

A touch of excitement today as the calm misty morning brought in numbers of Yellow Wagtails unseen on the island for a number of years. The trapping of 38 birds in the crown fields has brought the annual totals in line with those from the early 70's. Tree Pipits also put in a good showing with a flock of 60 around the Bill. A trickle of warblers through the obs area included a Garden Warbler, Grasshopper Warbler, 12 Sedge Warblers and double figures of Willow Warblers. A Green Sandpiper over the top fields was a timely delight along with two Whinchats.

24th August

A better feel today with the breeze having shifted firmly into the east but the rewards were still very much on the lean side for late August. At the Bill lingering hirundines were still plentiful and a late pulse of 50 Swifts was noteworthy but on the ground only Yellow Wagtail (40), Wheatear and Tree Pipit managed double figure totals of between 10 and 40 apiece; 3 Pied Flycatchers, a Marsh Harrier and a Grasshopper Warbler provided the only minor quality there, with elsewhere singles of Snipe and Pied Flycatcher were at the Grove and singles of Knot and Redshank were amongst the waders at Ferrybridge. Conditions were less than ideal for the seawatchers so 7 Balearic Shearwaters and a Storm Petrel were a bonus off the Bill.

We wouldn't have been surprised to be featuring a photo of something like the year's first Wryneck today but, sadly, it was a struggle to get beyond the likes of Wheatear © Geoff Orton...

...and Redshank © Pete Saunders:

A 'yellow' Clouded Yellow for comparison with yesterday's helice individual © Geoff Orton:

After the influx of Small Marbleds earlier in the summer it's not been a surprise to hear that larvae have been found at several sites in Dorset; we've only had a cursory look at the Fleabane in the Bill area and haven't noticed any feeding signs but the rich, dark colours of the moth trapped overnight at the Obs suggest that it may well have been locally bred  © Martin Cade:

23rd August

The murky skies of dawn that preceded an otherwise gloriously warm and sunny day had an air of promise about them but certainly didn't deliver. Apart from a fair-sized gathering of off-passage hirundines over the fields only Yellow Wagtail, Wheatear, Sedge Warbler and Whitethroat managed double-figure totals at the Bill, where a Grasshopper Warbler and the autumn's first passage Grey Wagtail provided the best of what little else could be uncovered; elsewhere, 3 Pied Flycatchers at Southwell wouldn't have attracted much comment in a routine late August but merited 'birds of the day' status this year. Ferrybridge continued to draw in the numbers, with 3 Sanderling, 2 Common Sandpipers and a Whimbrel providing a bit of minor interest.

One of the three Pied Flycatchers at Southwell today © Debby Saunders:

Clouded Yellows haven't exactly been numerous this year and we can't remember a mention of a helice individual until this one showed up near Culverwell today © James Phillips

Rather unexpectedly there looked to be a mass clear out of Painted Lady butterflies today; Hummingbird Hawkmoths though were still popping up pretty widely - this one was at Thumb Lane © Ted Pressey:

22nd August

Another little trickle of late August migrants as the Yellow Wagtails and Tree Pipits continued to increase slowly in number. The nets were quiet once more but a Grasshopper Warbler, Reed Warbler and 5 Sedge Warblers were added to the day list from trips around the crown field. Hirundine passage recommenced with another triple figure tally from the Swallows, 35 Sand Martins and 16 House Martins. Ferrybridge was a little quieter for numbers but maintained its excellent form on variety with singles of Greenshank and Curlew, two Knot and five Sanderling.

The two Knot at Ferrybridge had a similar expression to the assistant warden at that time in the morning... © Pete Saunders: 

21st August

Autumn progressed slowly on today with the first decent passage of Yellow Wagtails and Tree Pipits in the early hours followed by triple figures of Swallows and Sand Martins. The crown fields were once again harbouring a small flurry of Sedge Warblers while the sea was largely quiet with little more than five Balearic Shearwaters and an Arctic Skua along with low tallies of the usual fare. The wader flock at Ferrybridge continued to thrive with a pair of Whimbrel and a Knot joining the Ringed Plovers on the shore.

The island's still  awash with Painted Lady butterflies - surely many thousands in total - so it probably shouldn't be a surprise to see the odd freaky-looking one amongst them: this pale individual - seemingly lacking pigmentation rather than just faded - was at Coombefield Quarry yesterday © Duncan Walbridge:

And, as usual, there's plenty of other lepidoptera activity: Jersey Tiger, Adonis Blue and Wall Browns at High Angle Battery yesterday © Ken Dolbear...

...and the autumn's first Convolvulus Hawkmoth trapped overnight at the Obs © Martin Cade:

Ferrybridge is really alive with birds at the moment and the first juvenile Sanderlings are beginning to arrive amongst the 200 strong Ringed Plover flock © Debby Saunders (top) & Pete Saunders (bottom):

20th August

Just a hint of an upturn in passage today as the relentless wind of recent days finally begun to subside. Numbers were far lower than might have been hoped for the last third of the month but variety at the Bill included 30 Wheatears, 25 Sedge Warblers, 20 Whitethroats, 10 each of Yellow Wagtail and Willow Warbler, 2 Little Egrets and singles of Redstart, Grasshopper Warbler and Reed Warbler. An impressive 320 Ringed Plover topped the numbers at Ferrybridge, where 64 Dunlin, 8 Sanderling and singles of Knot and Redshank were also on show, whilst seawatching at the Bill came up with a steady southbound passage of Lesser Black-backed Gulls, 11 Sandwich Terns, 8 Manx Shearwaters, 5 Balearic Shearwaters, 3 Arctic Skuas.

19th August

Another unremarkable day was only saved from the recent monotony by a passing Osprey - initially seen heading south past Chesil Cove it was soon re-sighted as it headed on out to sea over the Bill. The sea was quiet with just a handful of Manx Shearwaters and a Bonxie west. Ferrybridge was still very busy, with 2 Black-tailed Godwits an addition to the tally for the last few days.

The autumn's first Osprey heading south high over the Bill © Martin Cade:

One of the two Black-tailed Godwits at Ferrybridge © Pete Saunders:

18th August

 A post-dawn deluge preceded a little flurry of migrants, particularly within the crown fields where two Grasshopper Warblers, 15 Sedge Warblers and a Tree Pipit were both seen and ringed throughout the morning. A small movement of Wheatears was evident with 13 recorded predominantly through the top fields. The sea was anti-climatic with only a single Arctic Skua of note. Ferrybridge was once again the place to be with a selection of waders including singles of Green Sandpiper, Whimbrel and Knot.

17th August

If yesterday was a day to forget then today barely merits a mention, even the Manx Shearwaters didn't make it to double figures. Four Balearic Shearwaters and 2 Bonxies made up the mornings sea-watch totals. The land was almost deathly quiet with a pair of Willow Warblers and four Wheatears making up the entire grounded passerine count for the day at the Bill. Ferrybridge held little to inspire with the usual selection of waders accompanied by the 2 long-staying Little Gulls.

The pick of the day's lepidoptera were a noticeable hatch/arrival of Clouded Yellows that included at least 11 at the Bill.

We've occasionally made reference on the blog to the acoustic bat monitoring - primarily to inform research into the migration of Nathusius' Pipistrelle - being undertaken at the Obs. Sadly, beyond managing the hardware, we still haven't found time to get involved in the analysis of the recordings obtained so we're fortunate that Adrian Bicker, who instigated this project in the first instance, is still on board to undertake this work. We were very excited to hear back from Adrian this week that amongst our latest batch of recordings he'd identified calls of the rare Kuhl's Pipistrelle from the evening of 3rd May (at 21:16; sunset on this date was at 20:19) when the bat detector was situated at the top of the Obs lighthouse tower:

Adrian comments that: Nathusius' Pipistrelles produce similar calls to Kuhl’s, with a strong, near-vertical FM “chirp” but such calls would be at or just above 40kHz. These calls are much lower – just like the 1,900 Kuhl’s calls collected from the Brittany coast as part of my spring Nathusius' Pipistrelle migration survey. Many of the Brittany calls had the diagnostic low, slow “ChowChowChow” (or “ChowChow”) social calls which confirm Kuhl’s. The spectrograms shows the calls.  The vertical axis is frequency (grid lines at 40kHz and 36kHz). The strong echoes show that the bat flew over the observatory’s flat roof; the 27ms delay indicates that the echo travelled 9m further than the call!

16th August

A day to forget, with the rain that rolled in as promised by mid-morning still not having cleared through by dusk. The sea was well-watched for as long as it was visible(!) but there were few rewards at the Bill beyond c200 Manx Shearwaters, 3 Balearic Shearwaters and an Arctic Skua. Odds and ends from what little other fieldwork was possible included a Tree Pipit at the Bill and 2 Little Gulls at Ferrybridge.

15th August

A break in the unrelenting wind and rain came with the first glorious sunshine for what feels like ages. The relaxed wind and clear skies didn't do us any favours on the birding front but the sea still produced 16 Balearic Shearwaters, three Arctic Skuas, singles of Bonxie and Storm Petrel, a strong passage of c.160 Mediterranean Gulls and the first two Guillemots since the colony dispersed at the end of last month. Land based passage was underwhelming with little more than a Yellow Wagtail over Ferrybridge, singles figures of Tree Pipit, 11 Wheatears, 10 Sand Martins and two Swifts at the Bill and 8 Sanderling and 2 Little Gulls at Ferrybridge.

Little Gulls have been a semi-permanent feature at Ferrybridge in recent weeks - one of these two has been pretty well daily there although the other bird was today making its first appearance since 1st August © Pete Saunders:

14th August

As the current spell of unsettled weather continued it was the partially obscured, rolling sea that was the focus for much of the day. With observers present throughout the daylight hours highlights from the Bill included a single Sooty Shearwater, three Arctic Skuas, 32 Balearic Shearwaters and 24 Arctic Terns. Chesil Cove was also watched at intervals through the day and produced singles of Black Tern and Storm Petrel as well as an additional 12 Balearic Shearwaters and 16 Sandwich Terns.

There were quite a few nice 'Balearic in amongst Manx' fly-bys today © Martin Cade:

13th August

A misting damp that refused to move for the early morning put pay to much of the ringing attempt. Land-based migrants were thin on the ground, even after the rain passed, and single figures of Wheatear, Tree Pipit and Lesser Whitethroat were all we could muster. The sea was also far less productive than of late with just 17 Balearic Shearwaters and 35 Manx Shearwaters, however, some oddities driven in by the rough weather included singles of Grey Plover, Pomarine Skua and Storm Petrel

The slightly droopy Grey Phalarope looked to have met a rather unfortunate end this evening as the local Kestrel obviously noticed its sad looking posture. The Little Tern flock continued to dwindle, it can't be long now before they're all gone for another year. Smaller numbers of common waders were accompanied by a lone Knot, six Sanderlings and 16 Turnstones.

Not long after dropping in on the Grey Phalarope this evening we'd turned our back whereupon we heard it call several times as if it had taken flight; on looking round we couldn't see the bird but then noticed a Kestrel landing nearby with prey that it immediately started plucking. When approached for a clearer view of its hapless victim the Kestrel flew off still carrying its meal that, at least from the feathers left behind, looked very much like it had been the phalarope...© Martin Cade:

12th August

Apart from a sudden and rather torrential downpour at midday the rain remained mostly in the channel. The looming storm clouds that slipped between us and the continent had the fortuitous effect of pushing the passing seabirds shoreward and as such the Balearic Shearwater tally for the morning reached 239, accompanied by double figures of Manx Shearwater, Common Scoter, Kittiwake and Mediterranean Gulls. The amassed gull flock, including a pair of Yellow-legged Gulls, attracted the interests of two passing Arctic Skuas although they did not linger for long. On the land the calming of the wind saw a trickle of migrants with the first double figure count of Tree Pipits, two Pied Flycatchers (dispersed across the island), 19 Wheatears and a Grasshopper Warbler in Culverwell. 

The wader-fest at Ferrybridge continued to gather steam with a maximum flock of 20 Knot, triple figures of Ringed Plovers and Dunlin and the lingering Grey Phalarope

Amongst the flock of Ringed Plovers at Ferrybridge the eagle-eyed watchers spotted a colour-ringed individual that it transpires was originally ringed on 7th July 2017 at Bylot Island, Nunavut, Canada - close to the northwestern limit of the species' breeding range. Of 93 birds ringed at this site 10 have been re-sighted on migration of which 4 were in the UK - 2 of these have been at Ferrybridge (the previous record being in 2014). We couldn't be more grateful to our dedicated local birders for this kind of brilliant information © Pete Saunders: 

The co-ordinator of this ringing project, Don-Jean LĂ©andri-Breton, kindly passed Pete and Debby Saunders an aerial photograph of the bird's breeding site in the Canadian high arctic and a link to a paper documenting certain aspects of the annual migration cycle of this population of Ringed Plovers: Seasonal variation in migration strategies used to cross ecological barriers in a nearctic migrant wintering in Africa

The local butterflies don't seem to have been put off by the recent spate of showers and wind, although the female of this Common Blue pair appears to be much smaller this is evidently typical of a second generation. The Painted Lady is so fresh its not too greater stretch to suppose it may have hatched here on the island © Ken Dolbear: 

11th August

Ferrybridge remained the place with both numbers and variety today, amongst which an early storm-driven Grey Phalarope was nice new arrival and a Little Ringed Plover was the first there for a while. Ten Wheatears, a handful of Willow Warblers, 3 Turnstones, 2 Swifts and singles of Sanderling and Sand Martin made up the very meagre migrant tally at the Bill where 2 Balearic Shearwaters passed by on the sea.

The Grey Phalarope was still showing traces of summer plumage and at first glance looked pretty sorry for itself © Pete Saunders...

...although it was perfectly able to fly about without any obvious sign of being inconvenienced © Debby Saunders:

And some video from the evening when it had moved from the main mudflats onto the creek and small pools beside the car park © Martin Cade:

The fledged Little Terns are still being fed by their parents but will surely be off any day now © Pete Saunders:

10th August

The wind that had freshened throughout yesterday reached well into gale force overnight and barely abated all day; with passerine hunting a lost cause all the day's attention was given to the sea and Ferrybridge, with largely expected results from both. It was way too windy off the Bill, where 8 Balearic Shearwaters, 7 Manx Shearwaters, 7 Dunlin, 3 Great Skuas, a Sooty Shearwater and an Arctic Skua were the only rewards amongst the c700 Gannets and c100 Kittiwakes that made up the bulk of the commoner fare on the move; 3 Yellow-legged Gulls were also grounded at the Bill, with 2 more off Chesil Cove where a lone Arctic Skua also put in an appearance. Ferrybridge was busy with routine waders, amongst which 23 Sanderling, 10 Kittiwakes, 3 Whimbrel and singles of Knot, Redshank, Little Gull and Arctic Tern provided interest.

The second Scarce Striped Grass-veneer Ancylolomia tentaculella for the island was an unlikely highlight from the Obs moth-traps on a night when nothing in its right mind should have been flying!

The ever-reliable Ferrybridge chipped in with a nice selection of storm-driven birds that included Arctic Tern, Kittiwake and Knot © Pete Saunders:

They're such an interesting-looking moth that we can't imagine even their eventual likely colonisation will ever truly devalue tentaculella but, status-wise, they're never again going to be the massive rarity they once were © Martin Cade: