An Interesting Chiffchaff in Staffordshire

Alrewas Pits, Staffordshire
Photo by Adam Archer

On the 25th January 2014 a Siberian Chiffchaff (of the race tristis) was reported from Alrewas Pits in Staffordshire. Last Saturday Dave Hutton and I visited the site in order to study the bird along with the accompanying Common Chiffchaffs (of the race collybita) of which there were at least six birds feeding around the perimeter of the sewage works. Almost immediately we located a frosty looking individual in the glorious late winter sunshine. We carefully tracked the highly mobile bird for a long while in hope that we would hear the typical mournful 'cheeet' call that would clinch it as a Siberian Chiffchaff. What we did witness however was something rather unexpected. The bird uttered a fairly typical 'hweeet' call of Common Chiffchaff. We left the site slightly confused in order to undertake more research into the intriguing and sometimes frustrating subject of chiffchaff identification. There were more straight forward birds to admire on site however with a distant female Long-tailed Duck and a female Smew along with a Little Egret and a single Oystercatcher.

Reported Siberian Chiffchaff - Alrewas Pits, Staffordshire
Photo by Dave Hutton

After spending hours studying the calls of various Siberian Chiffchaffs online and within the pages of my wonderful 'Sound Approach' books it was pretty obvious that the Alrewas bird was very unlikely to be a tristis. Dave then sent me through a series of excellent photos to look at and a quick glance at those shown here also made me think that the bird was not a Siberian Chiffchaff. In structure it did not appear to resemble the definite tristis birds that were present along the River Tame at Ladywalk Nature Reserve last year. The legs are nowhere near as dark in the Alrewas bird and the bill does not resemble the dark, slightly upturned looking spike of a typical tristis.  In an attempt to add to our knowledge Dave and I chased up another report of two Siberian Chiffchaffs at Hartshill Sewage Works last Sunday. Unfortunately all we found on site were several Collybita calling birds, including a slightly dull looking, brownish individual.

Hmmmm an interesting Chiffchaff - Alrewas Pits, Staffordshire
Photo by Dave Hutton

Yesterday (1st March) we headed back to Alrewas Pits for yet another look at the bird and hopefully this time we would secure a recording of the call. Unfortunately we left empty handed with the pale bird proving to be much more elusive and frustratingly quiet this time around. I did however manage to locate the female Scaup that I missed last week and the female Smew also showed quite well again so it was far from a wasted trip. With some mundane yet crucially important jobs to do around the house this morning it was left to the tenacious Mr Hutton to visit the site alone today. This time he managed to grab a few recordings of the bird, all of which sounded like the standard calls of collybita. Surely therefore this intriguing bird is much more likely to be of the subspecies abietinus or what is known in the trade as Scandinavian Chiffchaff. 

Probable Scandinavian Chiffchaff - Alrewas Pits, Staffordshire
Photo by Dave Hutton

Probable Scandinavian Chiffchaff - Alrewas Pits, Staffordshire
Photo by Dave Hutton

A sonogram of the Alrewas bird kindly provided by Alan Dean
This proves the bird to belong to the race collybita or abietinus... or hybrid?

Siberian Chiffchaff - Ladywalk Nature Reserve, Warwickshire
Photo by Dave Hutton (January 2013)

Siberian Chiffchaff - Ladywalk Nature Reserve, Warwickshire
Photo by Dave Hutton (January 2013)

An interesting Chiffchaff calling as tristis (possibly fulvescens?)
Photo by Dave Hutton (January 2013)

We have come a long way since the great British naturalist Gilbert White became one of the first to separate Chiffchaff, Willow Warbler and Wood Warbler by their songs in his classic 1789 book 'The Natural History and Antiquities of Selbourne' however we still have a lot to learn when it comes to breaking down the whole Chiffchaff complex even further. Here is a short overview of the various races of Chiffchaff courtesy of Birdipedia.

• P. c. collybita

This, the nominate form known as Common Chiffchaff breeds in Europe east to Poland and Bulgaria. It mainly winters in the south of its breeding range around the Mediterranean and in North Africa. It has apparently been expanding its range northwards into Scandinavia since 1970 and is now close to the southern edge of the range of P. c. abietinus.

• P. c. abietinus

This form known as Scandinavian Chiffchaff occurs in Scandinavia and northern Russia and winters from southeastern Europe and northeastern Africa east to Iraq and western Iran. It is intermediate in appearance between P. c. tristis and P. c. collybita, being grey-washed olive-green above with a pale yellow supercilium and underparts whiter than in P. c. collybita, but it has very similar vocalisations to the nominate subspecies. Due to individual variation it can be difficult to reliably separate P. c. abietinus and P. c. collybita outside their main breeding and wintering ranges. Some Common Chiffchaffs in the Middle East are browner and have a more disyllabic 'swee-hu' call than P. c. abietinus, and may belong to a poorly known taxon "brevirostris", further research is needed to clarify the affinities of this form.

• P. c. tristis

The Siberian Chiffchaff breeds in Siberia east of the Pechora River and winters in the lower Himalayas. It is also regularly recorded in western Europe in winter and it is likely that the numbers involved have been underestimated due to uncertainties over identification criteria, lack of good data and recording policies (Sweden and Finland only accept trapped birds). It is a dull subspecies, grey or brownish above and whitish below, with little yellow in the plumage, and the buff-white supercilium is often longer than in the western subspecies. It has a higher pitched 'suitsistsuisit' song and a short high-pitched 'cheeet' call. It is sometimes considered to be a full species due to its distinctive plumage and vocalisations. Nominate P. c. collybita and P. c. tristis apparently do not recognize each other's songs. Pending resolution of the status of P. (c.) fulvescens, which is found where the ranges of P. c. abietinus and P. c. tristis connect and may or may not be a hybrid between these, tristis is maintained in P. collybita.