Author: Mike Alibone

The Stanford Northern Wheatear

Posted on by Mike Alibone

Phil Tizzard raised the question of ageing Northern Wheatears in the UK in autumn. This is far from easy in the field, particularly with females. I’ve always thought that adult (winter)males exhibited a plainer, darker wing with less obvious feather fringing than juvenile/first-winter males, which is why I would have been inclined to have aged the Stanford individual as a juvenile/first-winter had I seen it in the field. It appears, however, that this is far from clear cut. According to Svensson (Identification Guide to European Passerines), the only infallible criterion for ageing these birds is the colour of the inside of the upper mandible, which is yellow in juveniles/first-winters as opposed to grey-black in adults. This means that attempting to age autumn Northern Wheatears in the field could be very tricky! The Stanford individual had a yellow inside upper mandible and so could be aged confidently as a first-winter (or, if you like, ‘older juvenile’). Here is another photo of it with its wings closed. Note how the upperparts appear greyer here than in the image in the previous post. 

Juvenile/first-winter male Northern Wheatear, Stanford Res, 27 August 2011 (Mike Alibone)

I like a challenge so I will be paying a lot closer attention to autumn Northern Wheatears in future … Thanks to Phil for bringing this up and to John Cranfield for helpful comments.

Spotlight on Stanford

Posted on by Mike Alibone

At the moment Stanford Reservoir is looking good. Very good. I spent this morning there with the Stanford Ringing Group, during which time 104 birds were trapped – although 28 of these were local retraps. As well as local breeders, many of those caught were autumn migrants with Blackcaps and Common Whitethroats predominating, although there were reasonable numbers of Willow Warblers, a few Chiffchaffs and a couple of Lesser Whitethroats and Reed Warblers. From next week just about all of the warblers trapped will be migrants. Two Treecreepers provided a great opportunity for close, in-hand scrutiny of their intricate plumage detail, which also enabled them to be confidently aged. The best bird trapped, however, was a Northern Wheatear, which is only the second ever to be ringed at Stanford (the other was on 5th September 1982) and, as

Juvenile Northern Wheatear, Stanford Res, 27th August 2011 (Mike Alibone)

such, caused a not undue amount of excitement among the members of the SRG! This individual was a juvenile and the black lesser and median coverts – along with some grey just visibly appearing on the scapulars – sex this as a male. It’s worth mentioning that the SRG will, for a small donation, organise ‘demo days’ in order to raise funds now that their previous funding has recently been withdrawn. By the way, rings now cost 20p each and the group is responsible for its own finances. With mist-nets costing in the region of £100 each ringing is not an inexpensive activity!

The water level at the reservoir itself is very low, almost resembling a small estuary, and the habitat there is proving a massive draw for waders. Among today’s haul were Knot, Spotted Redshank – initially found by Mark Piper – 7 Greenshanks, 11 Ringed Plovers, 2 Dunlin, Black-tailed Godwit and, together with Dave Warner, I counted a total of 18 Ruff – a tremendous figure for Northamptonshire in recent years.

My thanks to SRG’s John Cranfield, Mike Townsend, Adam Homer, Ed Tyler and Debbie for their jovial and instructive company this morning.

It’s the wader season

Posted on by Mike Alibone

Autumn waders start to appear at local reservoirs and gravel pits from July, although some (e.g. Green Sandpiper, Common Sandpiper) are as early as mid-June. These are returning adults but from about mid-August the first juveniles start to appear. Here are a couple of waders which were at Hollowell Reservoir this evening. Dunlin and Ringed Plover are common enough but how hard do we look at them? These two individuals are clearly

Juveniles of Dunlin and Ringed Plover, Hollowell Res, 19th August 2011 (Mike Alibone)

juveniles. The Dunlin has many fresh, broad, pale fringes to the upper parts – including a white mantle ‘V’ – and coverts but already there are two plain grey scapulars, with a dark shaft streak, of first winter plumage clearly visible. The Ringed Plover, as well as having a partly broken brown breast band, also has neat pale fringes to the mantle and coverts and I’m guessing it’s a nominate hiaticula race as it’s fairly pale, the supercilium behind the eye is quite broad and the bill appears quite thick, even though it’s collected a lot of mud. Other waders at Hollowell this evening were five move Ringed Plovers, three Green Sandpipers, two Common Sandpipers and four Greenshank. The water level continues to drop and it’s looking good for autumn …

Black-necked Grebe outwitted!

Posted on by Mike Alibone

Found late yesterday at Pitsford Reservoir and, despite its best attempts to outwit and elude this morning’s would-be observers (including me!), this fine summer-plumaged Black-necked Grebe finally gave itself up to those who entered Maytrees Hide and found it hugging the shoreline behind the reeds, where it remained invisible to birders looking from the perimeter path.

Black-necked Grebe, Pitsford Res, 14th August 2011 (Robin Gossage)

Only a few Black-necks are found in the County annually and many of these are juveniles in early-mid autumn plus the odd one or two in winter. Summer-plumaged individuals are rarely encountered so this one provided a real treat to those who were fortunate to see it this afternoon.

Red-backed Shrike at Thrapston GP

Posted on by Mike Alibone

A Red-backed Shrike was showing well in bushes by the river, opposite the hide on stilts at Thrapston GP’s Tichmarsh reserve late this afternoon. Alan Bull captured images of this splendid male, which is the first in the County since the last accepted record of a male at Hartwell on 24th May 2004. This species last bred in Northamptonshire in the 1960s.

Red-backed Shrike, Thrapston GP, 11th July 2011 (Alan Bull)

Northern Willow Warbler … in June!

Posted on by Mike Alibone

The Stanford Ringing Group has again been busy trapping rare warblers, having yesterday netted Northamptonshire’s second only Northern Willow Warbler. Identified on biometrics this race, acredula, which breeds as close as Norway, is regularly recorded on passage in the UK but what an odd time to find one inland in the Midlands!

Northern Willow Warbler, Stanford Res, 30th June 2011 (John Cranfield)

Normally Willow Warblers start moving south at the end of July. So where did it originate? It is a female with a brood patch growing over so maybe from Scotland (where this race is believed by some to breed) or maybe a Scandinavian breeder whose brood has failed and it decided to return south early? I would be pleased to receive comments on its possible origin. Interestingly, the only previous record of this race for Northamptonshire was also trapped by the SRG on 23rd August 2008.

At last … Honey Buzzard

Posted on by Mike Alibone

It’s about time we had one this year and John Peacock was lucky enough to catch this individual as it passed over the footpath near the Screen Hide at Summer Leys this morning. Initially mobbed by a crow, it circled and quickly gained height before moving off north-west at about 08.15.

Honey Buzzard, Summer Leys LNR, 30th June 2011 (John Peacock)

Plumage characteristics, such as the slightly darker secondaries than primaries, with barring conspicuous and filling the space between the covert barring and the darker trailing edge – as well as the outer primary barring extending out toward the darker tips – point to this individual being an adult female. Honey Buzzard is a scarce annual passage migrant with, over the last ten years, 2-4 records per year. In 2000 a record 37 were recorded as part of a national autumn invasion but prior to that there had been only 12 records in the 20th century.

Leucistic Willow Warbler

Posted on by Mike Alibone

Keith Smith sent me these images of a leucistic Willow Warbler, with plumage reminiscent of a domestic Canary, recently photographed at Summer Leys. It was along the old railway track at the far end of the reserve (opposite end to the car park) frequently dropping down out of view to feed, then appearing again in the same general area.

Leucistic Willow Warbler, Summer Leys LNR, June 2011 (Keith J Smith)
Leucistic Willow Warbler, Summer Leys LNR, June 2011 (Keith J Smith)

Leucistic Willow Warblers are rare but not without precedent. There are two recent, similarly striking, examples from Scotland involving returning breeding individuals (paired to ‘normal’ Willow Warblers) with a female on Mull in 2003 and 2004 www.mullbirds.com/Leucistuc%20Warbler.html and a male near Dalry, north Ayrshire in 2010 and again this year www.lizworld.com/Leucistic/Leucistic_WW.html.

To the tundra

Posted on by Mike Alibone

I found a flock of thirteen Ringed Plovers (with five Dunlin and a Little Ringed Plover thrown in for good measure) at Hollowell Reservoir this afternoon. The Ringed Plovers all seemed to be Tundra Ringed Plovers appearing relatively small and neat with quite dark mantles and, for those in the vicinity, only a ‘half size up’ from the Little Ringed Plover. But look at the contrast between the two birds pictured here. One is clearly

Presumed Tundra Ringed Plover, Hollowell Res, 30 May 2011 (Mike Alibone)

a male (black ear coverts, apparently wholly black breast band and sharp demarcation between the orange bill base and the black tip) and the other presumably is a female,

Presumed Tundra Ringed Plover, Hollowell Res, 30th May 2011 (Mike Alibone)

with dull brownish ear coverts and a narrower breast band as well as a narrower black band on the forehead. Unlike nominate race hiaticula Ringed Plovers, tundrae undergoes a late winter moult to summer plumage and so should always appear fresh in spring. I always get the impression that the breast band on tundrae is perhaps slightly narrower and more even in width than that on hiaticula but that’s just a personal perception – I haven’t seen it in the literature and I could be wrong. The two races intergrade and individuals with intermediate morphometrics and moult patterns have been recorded. To make matters worse, tundrae becomes larger again, further east in Siberia. Ringed Plovers are anything but simple!

All you ever wanted to know about optics … and more

Posted on by Mike Alibone

Just back from three great days in Wetzlar, Germany, with Carl Zeiss. No birds. Just optics. A very informative two-day seminar and factory tour which really brought home the reasons why top tier optics cost what they do. Expensive? Relatively speaking, they’re not. Find out why here. To Suzanne Challinor (Cley Spy), Richard Caplan (Richard Caplan), Ryan Longley (Focalpoint Optics), Tim Strivens (Viking Optical), Richard Cross (London Camera Exchange) and Paul Longley, Gary Hawkins and Walter Schwab (Zeiss) – a big thank you for being such good company over the last couple of days!