First for Hampshire – Iberian Chiffchaff in the New Forest
Iberian Chiffchaff by David Thelwell
Dan Houghton and Nigel Jones
Abstract
An Iberian Chiffchaff Phylloscopus ibericus was present at New Copse Inclosure near Brockenhurst, New Forest from May 10th-17th 2009. During this time, it remained faithful to a small area around a stream, often singing. The identification of this individual during its stay was not conclusive although most aspects of its plumage and song indicated an Iberian. The record has been accepted by the British Birds Rarities Committee (BBRC) and is the first record for Hampshire.
The following is an account of the finding and identification of the bird.
Introduction
[DH]: On May 10th 2009, Alan Butler, Mark Rolfe and myself visited New Copse Inclosure, near Brockenhurst in the New Forest to look for Pearl-bordered Fritillaries Clossiana euphrosyne. Whilst walking along a woodland ride towards a small stream, a chiffchaff began singing, however after the first few notes the song deviated from that of a typical Chiffchaff Phylloscopus collybita and my interest was aroused. I took video of the bird singing, on my digital camera, to record the song for later investigation. None of us had ‘scopes with us and the bird kept to the top of the trees, so no critical analysis of plumage was possible, but views through the bins revealed a yellow wash to the throat and upper breast and brownish legs. I commented to the others that the song sounded a bit like Iberian Chiffchaff but did not consider this as a serious possibility.
On getting home that evening I listened to recordings of Iberian Chiffchaff songs on the internet. These did indeed sound rather similar to the bird in question but not identical. I returned to the site the following day and watched and listened to the bird from 1100-1230 hrs, studying the plumage and getting a few more recordings of the song.
My only experience of Iberian Chiffchaff was a singing male in Devon in 2006. Being unsure
as to how much variation there is with the song of this species, I was reluctant to put the bird out as anything other than a possible. I posted about it on hoslist to try and generate some interest and get further opinions and a number of birders visited the site over the following week to see and hear the bird in question.
[NJ]: On the afternoon of May 12th, after reading comments on hoslist about the ‘iffy chiffy’, I decided to try to see the bird and see what could be made of its plumage and song. I had some previous knowledge of the species having seen the UK’s first record at Portland and had also studied them in Spain. It did not take long to find the bird perched up high in an ash and singing a mixed song. Very much like the well-known sketch with Morecambe & Wise and André Previn ‘It was playing all the right notes, but not necessarily in the right order’. The sequence of the notes were jumbled from what I would describe as a pure Iberian and more classic ‘chiff-chaff’ calls were being uttered in response to collybita Chiffchaffs singing locally. However, the plumage and structure looked fine for Iberian. I played collybita Chiffchaff song to the bird from my i-pod and got a lukewarm response. However, when I changed the song to Iberian Chiffchaff, and placed the player on the ground, the bird danced over the speaker within inches, singing incessantly and fluttering its wings in display. I took some photos and made some recordings. I knew the key feature to try and record was the down-slurred ‘piu’, but even though it was heard, I could not trace it on my recordings.
After returning home, I chatted with Brian Small (ex BBRC) and asked him what he thought
of the recordings I had made. He thought the BBRC would not accept the bird, as it was a
mixed singer. However, I should try to get a recording with the ‘piu’ call! Luckily, Dan Houghton had made some video recordings of the bird and captured this call – in the literature this call is described as ‘diagnostic of the species’. I knew we were now in with a good shot at getting the record accepted – despite all the people who had seen the bird and rejected it as a ‘funny collybita Chiffchaff’ or a hybrid!
Description
Plumage
 Crown, nape, mantle and scapulars an olive green-grey, the crown being slightly darker mottled. Tail feathers dark grey with narrow and whitish fringes. The flight feathers were also grey with pale fringes. These fringes were most prominent and off-white on the five outermost primaries and two innermost secondaries. The rest of the secondaries and inner primaries had narrower yellow fringes. Wing coverts appeared to have greyish centres with fairly diffuse pale yellowish fringes. Tertials were dark grey on the inner web. The outer web was paler grey becoming paler towards the fringe where it was greyishwhite. The rump and uppertail coverts were not seen.
Face – a dark eye stripe quite ill-defined extending behind the eye almost to the nape.
Supercilium widest, most prominent and lemon yellow in front of and above the eye,
becoming whiter and narrower behind the eye and extending as far back as the eye stripe.
Ear coverts pale grey with pale yellow mottling.
Underparts pale. A pale lemon yellow wash to the throat and upper breast down to the wing
bend, some limited yellow along the flanks and yellow undertail coverts. Belly and lower breast white.
Bare parts
Eye dark, appearing black. The eye ring was fairly weak being pale yellow above and white
below. Legs a mid-dark brown colour. Lower mandible of bill extensively pale pinkish-orange with a dark tip, this being very evident from below. Upper mandible dark brown. Bill appeared rather fine and ‘spiky’.
Structure/behaviour
 It always appeared longer-winged and longer-tailed than a collybita Chiffchaff though no direct comparison was possible. The tail was distinctly notched. The primary projection was difficult to judge in the field, due to the bird keeping to the tops of the trees. It had a habit of drooping its wings slightly so that the primaries fell parallel with the tail, when it could be seen that the wing tip fell just short of the tips of the longest undertail coverts. The wingtip/point appeared more elongate and less ‘blunt’ than a collybita Chiffchaff.
From photographs, the primary projection was judged to be just less than two-thirds that of
the exposed tertials, possibly longer.
When singing the bird preferred high, fairly exposed perches near the tops of the trees c.10-15 metres up and had a tendency to remain perched in one spot for relatively long periods rather than flitting from perch to perch. It seemed to favour a couple of Ash trees which were just breaking into leaf.
Vocalisations
Call A down slurred, sad ‘piu’, sounding rather Siskin Carduelis spinus-like.
Song The song basically consisted of up to three different sections:
Section 1 – a series of ‘chiff’ notes repeated five to nine times. There was some variation
in pitch but nothing as marked as the chiff-chaff song of collybita Chiffchaff. The delivery of
these notes was also faster than that of collybita Chiffchaff. Every song began with these.
Occasionally the rattly section was followed by one or two chiffs.
Section 2 – a series of ‘wheep’ notes repeated two to six times. When given this formed the
second section of the song following the chiffs and preceding the rattle.
Section 3 – a rattly phrase reminiscent of Cetti’s Warbler Cettia cetti which could be repeated up to three times and often the terminal part of the song when uttered.
DH recorded 26 bursts of song given by the bird over two days. These were timed using a
stopwatch and two were less than three seconds in length, 21 were between three and four
seconds and three were longer than four seconds with the longest being c.4.5 seconds. The
majority (14) were 3.6–4.0 seconds in length.
Each song was made up of at least two of the sections described above. Of the 26 songs,
the order they were delivered in and the frequency of each are detailed below:
‘chiffs’ followed by ‘wheeps’ (12)
‘chiffs’ and rattle(s) (5)
‘chiffs’, ‘wheeps’ and rattle(s) (3)
‘chiffs’, rattle and ‘chiff(s)’ (1)
‘chiffs’, ‘wheeps’ and ‘chiffs’ (3)
‘chiffs’, rattles and ‘wheep’ (2)
The low ‘tsrr tsrr’ notes between bursts of song that collybita Chiffchaff often makes was
never heard.
Discussion
It is very likely that this bird had been present at the site for some time prior to May 10th, as it is not the kind of place that would be regularly watched and therefore the song could have been ‘corrupted’ before discovery. It was last reported on May 17th.
Apart from the song, the bird appeared to be a classic Iberian Chiffchaff and whether the
variation in song could be explained by it being in its first-summer and having not crystallised
its song, or a hybrid influence, was unknown to us. From reading the literature it appears that male Iberian Chiffchaffs that are in territories alongside collybita Chiffchaffs may include more classic ‘chiff-chaff’ in their song repertoires – the so-called ‘conflict song’.
It was felt that if the bird was not a pure Iberian Chiffchaff, it should still be documented as
fully as possible and submitted to the British Birds Rarities Committee. Subsequently, the record was accepted as a pure Iberian Chiffchaff.
Acknowledgements
We would like to thank Ashley Howe for getting the first good photos of this bird, Martin Collinson for doing the clinching sonograms from recordings of the song and call, and everyone who showed an interest in this bird.
References
Collinson, J.M. and Melling, T. 2008. Identification of vagrant Iberian Chiffchaffs – pointers, pitfalls and problem birds. British Birds 101: 174-188.
Dubois, P.J. 2008. Mixed-singing Iberian Chiffchaffs: is it their ‘swan song’? British Birds 101:
379-380.
Richards, C. 1999. The Iberian Chiffchaff in Dorset. Birding World 12: 193-200.
Small, B. Iberian Chiffchaff in the UK. Surfbirds online article.
D.P. Houghton
Nigel Jones 29 Straight Mile, Romsey, SO51 9BB
Photos copyright Nigel Jones
Painting copyright David Thelwell (http://www.dathelwell.co.uk/)
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