Rarity Round-up, 25th to 31st August 2018

Apart from a prolonged spell of rain on 26th, the weather remained largely dry and undramatic, with a westerly bias to the wind and a wave of warm air pushing up from the continent at the week’s end. Waders were again at a low ebb, Ospreys were widespread and then there was the curious case of a roadrunner …

In the absence of any other wildfowl – save three Pintails at Pitsford Res – Garganeys were this week’s ducks deluxe, with one at Hollowell Res on 28th and the other hanging on in there at Stanwick GP until at least 29th. The latter site also held on to its mobile Great White Egret and two were there on 29th, while up to two were still present on Thrapston GP’s Titchmarsh LNR throughout the period. Some interchange between these two sites is highly likely.

Ospreys just keep coming. Singles were recorded from seven localities – one up on the last review period – these including Hollowell Res and Pitsford Res on 25th, Thrapston GP on 27th with a juvenile south over Daventry CP and then south over Fawsley Park Lake 25 minutes later on the same date (great tracking!) and at Ditchford GP and over Borough Hill on 31st.

Which brings us on to the bizarre tale of a small, spotty bird seen scuttling across the A428, just west of Clifford Hill GP, early in the morning on 29th. The county’s first Spotted Crake since Stanwick in August 2012 narrowly avoided an untimely end under the wheels of the observer’s vehicle but it was seen well enough to identify – spots an’ all – before it disappeared into Hardingstone Dyke on the south side of the road. Has it been looked for since? You have to go back to the last century for records prior to the Stanwick bird so they’re not that easy to come by locally. The closing hours of daylight may pay dividends for the keen optimist hoping for a dalliance at dusk …

Juvenile male Ruff, Hollowell Res, 27th August 2018 (Mike Alibone)

The dearth of waders continued, with Hollowell producing the only waders of note – a Ruff on 27th and two short-staying Spotted Redshanks two days later, on 29th. The latter date produced both of this week’s Mediterranean Gulls – evening juveniles at Boddington Res and Ringstead GP, while single-figure counts of Yellow-legged Gulls came from Daventry CP, Hollowell Res, Pitsford Res and Wicksteed Park Lake, although twenty-one were counted at Stanwick on 30th.

Juvenile Mediterranean Gull, Boddington Res, 29th August 2018 (Gary Pullan)
Yellow-legged Gull, Wicksteed Park Lake, 27th August 2018 (Alan Francis)

On the passerine front, just two Common Redstarts were found this week, comprising one at Borough Hill on 28th and a juvenile male trapped and ringed at Stanford Res on 31st. More Whinchats appeared, with singles at Welford Quarry on 25th, Borough Hill on 28th and Chelveston AF on 30th and two were near Kettering at Wicksteed Water Meadows on 28th-30th. An arrival of Northern Wheatears saw thinly-scattered singles at Harrington AF on 25th, Pitsford Res on 28th, Alderton and Chelveston AF – both on 30th – and two were at Orlingbury on 29th.

Northern Wheatear, Alderton, 30th August 2018 (Mike Alibone)

Migrant Tree Pipits continued to be found, with 25th producing flyover singles at Croughton Quarry and Naseby Res and one ‘on the ground’ at Welford Res, followed by two at Borough Hill on 28th.

Rarity Round-up, 11th to 24th August 2018

The weather for the last two weeks, now firmly dominated by Atlantic low pressure systems, has remained largely dry and has not been a key influencer on the appearance of birds locally. While wader passage has yet to gather pace, the movement of passerines gained momentum, with the mist nets of Stanford delivering yet more surprises.

Apart from a Ruddy Shelduck at Welford Res on 24th, keeping wildfowl afloat during the review period, Garganeys were present at four localities, the most notable of which was Stanwick GP, where an eclipse drake was present between 11th and 20th. Elsewhere, singles visited Summer Leys LNR on 12th and 15th and both Pitsford and Hollowell Reservoirs on 18th.

Eclipse drake Garganey, Stanwick GP, 16th August 2018 (Mike Alibone)

Meanwhile, the site most consistent for producing Great White Egrets was again Thrapston GP, where two were frequently present on Titchmarsh LNR throughout the period, with the same site producing three together on 19th. There may have been some movement of the third bird between here and Stanwick, where one was seen on 11th-12th, 14th and 23rd-24th with perhaps the same individual visiting Ditchford GP on 24th. The one lingering at Daventry CP was seen almost daily until 18th and one visited Hollowell Res on 20th.

Ospreys were recorded from six localities, again prominent at Thrapston GP and Hollowell Res – both sites producing two together on several occasions. Away from these locations, two drifted north over Moulton on 13th and singles were at Pitsford Res on 14th, Priors Hall (Corby) on 19th and Ditchford GP on 23rd.

Osprey, Hollowell Res, 19th August 2018 (Martin Swannell)
Osprey, Thrapston GP, 21st August 2018 (Alan Francis)
Juvenile Osprey, Ditchford GP, 23rd August 2018 (Tony Vials)

Marsh Harrier action ramped up during the period with two juveniles flying west over Ditchford GP’s Irthlingborough Lakes & Meadows on 11th, followed by singles north of the causeway at Pitsford Res on 14th-15th, over Thrapston GP on 16th and 21st-22nd and over Keepers Lodge Bay and adjacent fields at Stanford Res on 21st.

It was the worst two-week period for waders with, aside from small numbers of commoner waders, the only birds of note were two Ruffs at Summer Leys on 15th – and that’s scraping the barrel!

The second Black Tern of the autumn, a juvenile, appeared at Hollowell Res on 22nd and the season’s first Little Gull was found off the dam at Stanford Res on 21st but it did not linger. Mediterranean Gulls were rather more obliging, however, with single juveniles visiting Ditchford GP IL&M on 11th, Hollowell Res on 14th, Pitsford Res on 15th and Stanwick GP on 20th, while an adult was found at Daventry CP on 23rd.

Juvenile Mediterranean Gull, Stanwick GP, 20th August 2018 (Steve Fisher)

There were only three Caspian Gulls, though, an adult at Hollowell Res on 11th and two – an adult and a first-summer – together at Daventry CP the following day and Yellow-legged Gulls were reported from five localities, with a maximum count of eight at Stanwick on 20th.

Adult Yellow-legged Gull, Stanwick GP, 23rd August 2018 (Steve Fisher)

And so to passerines, which saw a bit of an upturn in numbers as well as another quality warbler – even if only a ‘sub’ – being pulled again from a mist net at Stanford Res. The fourth Northern Willow Warbler for the county was trapped and ringed on 21st, following the previous three identified by the same means there in 2008, 2011 and 2014.

Northern Willow Warbler (left) and Willow Warbler, Stanford Res, 21st August 2018 (Chris Hubbard)

Beyond this, up to four Common Redstarts were regularly to be found at Twywell Hills & Dales between 14th and 23rd, with the same site producing a Whinchat on 16th-17th, while further singles were at Borough Hill on 20th and near Glapthorn on 22nd.

Male Common Redstart, Twywell, 16th August 2018 (Bob Bullock)

Back to Stanford for one of the most difficult passerines to find locally since it stopped breeding locally: Tree Pipit. No less than four were trapped on 21st

Tree Pipit, Stanford Res, 21st August 2018 (Chris Hubbard)

If you’re lucky it’s a late August flyover migrant at Borough Hill or Harrington – a tease or ‘teez’, whichever way you look at it.

Northern Willow Warbler at Stanford

Northamptonshire’s fourth-ever Northern Willow Warbler was pulled from the nets of the Stanford Ringing Group, at Stanford Reservoir, this morning.

Willow Warbler comprises three subspecies – nominate trochilus from Britain, central Europe and southern Scandinavia, acredula (‘Northern Willow Warbler’) from northern Scandinavia, Russia and western Siberia and yakutensis (‘Siberian Willow Warbler’) from central and eastern Siberia. However, the subspecies are not well defined and there is extensive intergradation. Furthermore, variation is not linear, and birds showing the characters of one subspecies occur regularly within the range of another (BWP).

Northern Willow Warbler, Stanford Res, 21st August 2018 (Chris Hubbard)

Fortunately, visual characteristics, when combined with in-hand biometrics allow identification of acredula to be made. Trying to do so in the field, however, is more than a challenge on an out of range individual! This one is a typical, cold, pallid individual, with reduced yellow tones and quite a striking supercilium.

Northern Willow Warbler (left) and Willow Warbler, Stanford Res, 21st August 2018 (Chris Hubbard)

This is the fourth record of acredula for Northants, all of which to date have been trapped at Stanford! Previous records were 23rd August 2008, 30th June 2011 and 8th September 2014.


Rarity Round-up, 28th July to 10th August 2018

With local temperatures hitting 30°C, this two-week period saw the heat waver before coming to an abrupt end during the last two days. It was back to sweeping Atlantic low pressure systems, average temperatures and heavy showers setting in on 10th, creating a truly autumnal atmosphere. Among the more common migrants, there were a few surprises – not least of which was Northamptonshire’s fourth-ever Marsh Warbler.

Three Garganeys appeared during the latter half of the period, comprising singles at Pitsford Res on 3rd, Hollowell Res on 7th and Stanwick GP on 8th and 10th, while the only other wildfowl were five Red-crested Pochards still at the first of these localities on 3rd. A Bittern at Stortons GP on 5th was, at first sight, surprising, although this species is now being seen more frequently outside of the traditional winter period as the UK population continues to grow. Also doing well, Great White Egret totals increased by 150% as the two long-stayers at Thrapston GP became three on 8th and further singles were at Stanwick GP on 28th-31st and presumably the same again on 8th-10th, while another was at Daventry CP from 7th to 10th.

Great White Egret, Daventry CP, 7th August 2018 (Gary Pullan)
Great White Egret, Stanwick GP, 8th August 2018 (Steve Fisher)

Three localities produced Ospreys. Singles visited Stanford Res on 31st and 6th, Hollowell Res on 5th, with two there on 8th, and Thrapston GP on 4th-5th, with three there on 9th. Thrapston also produced a Marsh Harrier on 28th and further singles were subsequently seen at Summer Leys LNR on 1st and at Priors Hall, Corby on 5th.

In stark contrast to the large flock recorded at Stanwick on 27th July, the only Whimbrel during the period was one which stayed briefly at Hollowell Res on the evening of 4th.  Black-tailed Godwits, too, were fewer in numbers with singles at Stanwick on 30th-31st and 10th, although three were present there on 9th. Further singles were at Ditchford GP on 3rd (followed by two there on 7th), Stanford Res on 4th, Hollowell Res on 5th and 8th, Naseby Res on 5th, while two were at Thrapston GP on 8th-9th and four adults – one with a series of colour rings – visited Daventry CP on 9th. The only other notable wader was a Turnstone at Thrapston GP on 3rd-4th.

Black-tailed Godwit, Stanford Res, 4th August 2018 (Chris Hubbard)

The first Black Tern of the autumn was found at Clifford Hill GP on 28th but gulls were poorly represented over the period. Hollowell Res produced an adult Caspian Gull on 5th and a juvenile visited Daventry CP on 9th-10th but there were no large counts of Yellow-legged Gulls. Singles of the latter species were at Thrapston GP on 3rd-4th and Hollowell Res on 7th-8th, while four were at Stanwick GP on 4th and at least four were at Daventry CP on 7th and 9th, with 5 there on 10th.

Passerines were certainly well represented in quality, if not quantity, during the period. A Wryneck was discovered ‘anting’ along the track approaching Foxhill Farm, just south of Daventry, on 4th. Shortly after its discovery, it appeared to move off to an adjacent woodland and was not seen subsequently. This follows a spring record at Thrapston GP so two of these amazingly-marked little ‘woodpeckers’ in one year is excellent.

Marsh Warbler, Stanford Res, 9th August 2018 (Chris Hubbard)

Outshining them in rarity but not in character, was the county’s fourth-ever Marsh Warbler – and the first record for twenty years – trapped, ringed and released at Stanford Res on 9th.

Juvenile Whinchat, Stanford Res, 6th August 2018 (Mick Townsend)

Other than that, a juvenile Whinchat was also trapped at Stanford Res on 6th and a Northern Wheatear was found at Harrington AF on 4th.

Marsh Warbler at Stanford

A routine ringing session at Stanford Reservoir this morning produced Northamptonshire’s fourth-ever Marsh Warbler.

It was trapped, ringed and released along the rear edge of Blower’s Lodge Bay at approximately 11.00. Thanks to Chris Hubbard for the images below.

Juvenile Marsh Warbler, Stanford Res, 9th August 2018 (Chris Hubbard)

The lack of contrasting rufous rump (of Reed Warbler) is an immediate pointer to identification, as are the pale-tipped primaries, although they are not as obvious as on some Marsh Warblers. Also pale fringes to tertials are more obvious than on Reed Warbler.

Juvenile Marsh Warbler, Stanford Res, 9th August 2018 (Chris Hubbard)
Reed Warbler (left) and Marsh Warbler, Stanford Res, 9th August 2018 (Chris Hubbard)

Marsh Warbler’s slightly shorter bill, plus eye-ring and supercilium equally distinct compared to Reed Warbler’s, are just about visible in the above image. Visually, though, they are still difficult to tell apart!

Marsh Warbler is just about hanging on as a rare breeding species in the UK, with perhaps only eight pairs restricted to sites on the east coast. Otherwise, it is a rare migrant.

Interestingly, two of the previous three records are from Stanford and include one trapped on 17th June 1984 and a singing male on 16th May 1989. The third was a singing male at Stanwick GP, twenty years ago, on 7th-9th June 1998.

Please note access to Stanford Reservoir is by permit only, issued by Severn Trent Water Authority.