Identification of female Pine Buntings Colin Bradshaw and Martin Gray ontroversial birds are a double-edged sword for the British Birds Rarities C Committee. They take up an inordinate amount of members' time and effort, but out of this frequently comes a clearer understanding of a complex problem. It is rather more frustrating if, after all the effort expended, we are only a little nearer the Solution than when we started. Such is the Situation with the 'Big Waters bunting', present in Tyne & Wear from 18th February to 16th March 1990. Was it a Rne Bunting Emberiza kucocephalos, as originally claimed, a Yellowhammer E. citrinelk, perhaps of the less-yellow eastern race erythrogenys, or even a non-yellow Yellowhammer as others have maintained (and do genuinely non-yeüow Yellowhammers really exist?), or was it perhaps even a hybrid between the two species? On first circulation to the Committee, nine members voted to 'pend for more information' and one to reject on the grounds that female Pine Buntings are probably not identifiable in the field. Two subsequent claims of female Pine Bunting, from North Ronaldsay, Orkney, on 12th-13th October and lst- 5th November 1991, were also 'pended'. When such an impasse occurs, the BBRC frequently enlists the help of outside experts, often from abroad (which helps to explain why some records of 'difficult' birds take a long time before a final decision is reached). On this occasion, we sought help from three bunting experts, two of whom opted for Pine Bunting (with detailed reasons why) and the third From the Rarities for Yellowhammer (without giving reasons). Following Committee's files much discussion, and in the uncommon Situation where Sponsored by 'present knowledge' was insufficient, the BBRC decided to 'go public' on this issue and to discover what other IZEISS sources of information and opinion could be tapped by explaining the current position and various personal Germany views. 378 \Brit. Birds 86: 378-386, August 1993] Identification offemale Pine Buntings 379 Big Waters bunting, 1990 This bird has appeared in words and photographs so many times over the past two years that there can be few who are unaware of its general appearance. Since it was at a feeding Station for a month, thousands of birders were able to watch and photograph it at close ränge (plates 124 & 125). Initially, it was provisionally identified as a female Pine Bunting on the following characters: (i) it stood out from the Yellowhammers present in being noticeably pale, especially on the mantle, which was a cold, pale grey-brown; (ii) in the Seid, despite close and detailed scrutiny, it showed no visible yellow; all other plumage colours appeared normally saturated, making leucism less likely; (iii) the fringes of the primaries were a gleaming white, with no hint of yellow; (iv) a very prominent white submoustachial stripe curled behind the ear-coverts and joined a pale grey nape side; (v) the belly was white and unstreaked, extending as an inverted 'V into the lower breast; (vi) the lesser coverts were a uniform grey-brown, with no hint of Yellowhammer's pale notching. In addition, it showed several other features, many of which CB had noted on Pine Buntings in Siberia: (i) a prominent white eye-ring; (ii) a distinctly bicoloured bill, with dark upper and pale lower mandible; (iii) a whitish central nape spot bordered on each side by a short dark bar; (iv) a row of thin streaks on the white throat, with an isolated crescent of unmarked white below (see fig. 1); (v) the cap was pale grey, but so heavily and regularly streaked as to appear uniformly dark, and it never showed the pale central crown present on many Yellowhammers (and some Pine Buntings). Controversy revolved around the general plumage tones of this individual. Why was it so cold and grey, with very little brown in the plumage? It seemed unlikely to be leucistic, as the rufous on the rump, tertials and lowest row of scapulars appeared normal. Admittedly, it did become marginally browner during its stay and some chestnut became visible in die streaking on the breast sides, but, given the limited Information available in the literature, it seemed difficult to believe that a Pine Bunting could be this cold. Fig. 1. Head pattern of presumed female Pine Bunting Emberizfl laxocephalos, Big Waters, Tyne & Wear, February/March 1990 {Martin Eccks). Note: prominent white submoustachial stripe, white eye-ring, bicoloured bill, row of thin streaks on white throat with isolated crescent of unmarked white below, heavily streaked crown with no pale central streak Identification of female Pine Buntings 381 FACING PACK 123-127. Fine Buntings Embaiza leucoaphalos and Yellow-hammers E. cibimlta 123. 'Fop left, female Pine Bunting, North Ranaldsay, Orkney, 1st November 1991 (D. Paltmcm) 124 & 125. 'Pop right and upper centre, 'Big Waters bunting' (see text), with Yellowhammers in lower photograph, Tyne & Wear, February 1990 (C. Braitshcuv} 126. Lower centre, putative hybrid between 'Big Waters bunting' of 1990 and Yellowhammer, with two Yellowhammers, Big Waters Reserve, Tyne & Wear, January 1991 (C. Bradshaw) 127. Bottom, male Pine Bunting with male Ycllowhammer, Northumberland, February 1992 {Eric Birdi In a subsequent article on identification of female Pine Buntings (Birding World 3: 89-90), Ian Lewington highlighted the following as being important features: the crown streaking; pattern of the malar stripe; relative absence of streaking on undertail-covcrts; and the contrasting breast pattern, with blackish streaking in the centre fading to the sides. He concluded drat the Big Waters bird was an abnormally pale Pine Bunting: a conclusion that many found difficult to believe, feeling that this was either a normal Pine Bunting or a very abnormal Yellowhammer. Big Waters buntings, 1991 During January-February 1991, two unusual-looking buntings intermittently visited the feeding stations at the Big Waters Reserve. Bodi showed the same washed-out mantle coloration as the 1990 individual, but both had bright yellow primary edges and a pale yellow suffusion on tire belly; one also had a yellow throat (plate 126), while the other had an intriguing yellow spot in the middle of the crown. Again, both looked quite unlike any of the Yellowhammers present and were immediately striking owing to their pale plumage. The question then posed was: were these hybrids of the 1990 'Pine Bunting' with a Yellowhammer, or was there a 'non-yellow' gene in the local Yellowhammer population which manifested itself in these three birds in different ways? Expert opinions The BBRC sought advice on the identity of the three buntings, on the criteria useful in identifying female Pine Bunting, and on the identification of hybrids. We received detailed comments from Urban Olsson and Professor Eugeny Panov. Both thought that the original 1990 bunting was a female, that it was probably a first-winter, and that its coloration was within die normal range for Pine Bunting. UO pointed out that this coloration is due partly to broad pale fringes to the body and covert feathers obscuring the colours below (these were visible on tire photographs which had been sent); as the fringes wore off, 382 Identification of female Pine Buntings the bird would become less cold, darker and brighter. EP stated that the coloration of female Pine Bunting is rather variable, particularly with regard to the following characters, all of which vary more or less independently: (i) light background to head, breast and belly plumage (varies from dull, dirty sandy to almost white); (ii) amount of dark markings on head and throat; (iii) amount of chestnut (feathers) on head and diroat; (iv) colour of dark streaks on sides of upperparts; (v) amount of white on nape; (vi) general colour of mande (which also tends to be slightly paler and duller in winter). They differed in their opinions of the 1991 buntings. UO felt that these looked exactly as he would expect a hybrid to look, 'a sort of mosaic between mainly Pine Bunting-type pale plumage and uhen rather bright yellow colours in limited areas', but added that the only way to be sure would be through DNA analysis. EP felt that they were more likely to be first-year Yellowhammers with a limited amount of yellow, but that it was 'impossible to distinguish on phenotypical characters only between first-year Yellowhammer and first-year hybrids'. Bom enlarged upon the question of hybrids (see below). In contrast, Hadoram Shirihai consulted with colleagues in Israel, where both Pine Bunting and Yellowhammer winter. They came to the conclusion that the original 1990 bunting was a non-yellow Yellowhammer, but time and workload prevented HS from giving reasons. Orkney buntings, 1991 In autumn 1991, MG, despite being on crutches, found two different female buntings on North Ronaldsay: on 12th-13th October, and on lst-5th November. Both gave excellent views and were identified as female Pine Buntings, the second being aged as a first-winter (plate 123). The most immediate feature of both was their general cold, pale plumage, which MG likened to die effect of a Common Redpoll Carduelis flammea of the 'mealy' race flammea in a flock of the 'lesser' race cabaret. Neimer was quite so cold as the 1990 Big Waters bunting, and both showed fairly obvious chestnut streaks on the breast sides (a very difficult feature to see on the Big Waters individual). These appeared to be more typical Pine Buntings, but bom records were 'pended' by the Committee while investigations were .carried out into the identification features of the species. What was noticeable from the descriptions of all three buntings was the large degree of overlap in features that were noted as 'different'. It is from these areas of overlap that the list of potential separation features (see below) is drawn up.