Dear All
Sillem's Mountain Finch /Leucosticte sillemi/ is a species known only from two specimens collected by Dutch explorer Jérôme Alexander Sillem during the Netherlands Karakoram Expedition in 1929 from Kushku Maidan, a barren plateau in the Xinjiang Autonomous Region in western China, at an altitude of 5125m. One bird is a worn adult male, and the other a juvenile male with wings not yet fully grown (implying that the species bred in the area).
Both specimens languished in a mixed drawer of /Leucosticte /and /Montifringilla /finches in the collection of the Zoological Museum of Amsterdam, labelled as Brandt's Mountain Finch /L. brandti/, until Prof.
C. S. Roselaar noticed in 1991 that they did not match the other specimens in the drawer. A comparison with 400 specimens of /L. brandti/ established that the birds represented a new species; in particular, the grey-fringed flight feathers, tawny-cinnamon head and neck, and an absence of black on the lores and forehead all serve to separate it from Brandt's Mountain Finch. In addition, the juvenile is heavily streaked above, unlike any juvenile Brandt's. He named the new species L. sillemi in a paper in the Bulletin of the British Ornithologists' Club in 1992.
Oriental Bird Images (OBI), the image database of the OBC, has photographs of the type specimens, kindly contributed by Prof. Roselaar.
Yann Muzika is an excellent wildlife and nature photographer who has for a while been a regular contributor of superb bird photos to OBI. In August, he sent me a batch of photographs he had taken during an (ultimately aborted) trek in June in the Yenigou Valley on the Tibetan Plateau in western Qinghai, China. This batch included “..a mystery bird (!), a snow finch that I can't ID with the McKinnon [field guide] and having browsed the OBI database… please have a look and let me know which bird I have overlooked!”
I processed and uploaded Yann’s photos to the website one-by-one until I came to the mystery bird. It’s hard to describe exactly my feelings when I set eyes on the image. The words “Sillem’s Mountain Finch” simply popped into my head, and I sat there for a little while somewhat awestruck. I did some initial checking and then emailed Yann back with a somewhat understated “Rather worryingly, it looks rather like the long lost Sillem's Mountain Finch.”
Yann had taken more images but was currently away from the computer where he had them stored, and it took him a while to send those to me.
There followed a considerable period of checking of references to make sure we hadn’t overlooked any other possibilities. We then checked with Jesper Hornskov, Dave Farrow and Paul Holt who had all had considerable experience of birding the Tibetan Plateau. All are agreed that this has to be Sillem’s. The crowning confirmation came when we sent the photos to Prof. Roselaar who immediately replied “Phantastic! At last proof that sillemi still exists.”
Since then Yann has gone back and checked through other photographs he had obtained at the site, of what he had originally taken for female Tibetan (Roborowski’s) Rosefinches /Kozlowia (Carpodacus) roborowskii/, which were fairly common there. He found that he appeared to have two similar but actually rather different streaked female types in his photographs. One is definitely female /K. roborowskii/; the other shows the same structure as the male Sillem's and, on further analysis, appears to differ from all other similar finches. We think it is the hitherto undescribed female of Sillem’s Mountan Finch.
Yann deserves full credit for this exciting find and plans to go back to the area again next summer to look for the bird. Obviously, more work has to be done in order for full scientific verification. This will probably involve trying to relocate the birds, trapping some for full examination and taking a small blood sample for DNA analysis, for which permits and the co-operation of the local authorities will be needed.
The original specimens were collected near the western end of the Kunlun Mountain Range at an altitude of 5125m on the Tibetan Plateau. Yann found his birds two days trek away from the nearest road in a boggy area at around 5000m towards the eastern end of the Kunlun Range on the Tibetan Plateau, about 1500km from the original collection site. The species appears therefore to be a high altitude specialist. Since the area experiences little snowfall in winter, it may well remain on or near this area throughout the year. However, it is probably fairly scarce, since no one has seen it since it was first collected. We would therefore encourage birders to look out for the bird anywhere in this vast potential habitat, perhaps at more accessible locations along the Golmud-Lhasa highway, and in particular around and above the Kunlun pass (4760m, 160km South of Golmud) and the Tanggula pass (5230m, around 200km further south). More sightings and photographs would be very welcome. Hopefully, we may learn more about its distribution and habitat requirements and endeavour to ensure that it continues to survive.
I will try to post some more information about comparisons with similar species soon. In the meantime, here are some links you may wish to follow to see photos of the bird, etc.:-
- Yann’s blog:
http://thewildernessalternative.com/2012/10/20/sillems-mountain-finch-rediscovered/
- Page on OBI:
http://orientalbirdimages.org/leucosticte-sillemi.html
- Specimen photos:
http://orientalbirdimages.org/search.php?Bird_ID=1973
- ZMA site:
http://nlbif.eti.uva.nl/zma3d/fringillidae9.html
- Artist's impression from skins, but text includes some nonsense about bisexual birds:
http://www.sillem-family.com/sillems-finch.html
Best regards
Krys
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Krys Kazmierczak
OBI Editor
krys AT krys.net
imagemaster AT orientalbirdimages.org
www.orientalbirdimages.org
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