A Whimbrel showing the characteristics of Steppe Whimbrel Numenius phaeopus alboaxillaris in the Seewinkel, Austria, April 2017
By Johannes Laber & Gary Allport
In the course of a waterfowl survey on 22nd April 2017 in a meadow north-east of the Lange Lacke, Seewinkel, Austria, JL found a loose group of 25 Whimbrels. Amongst them was a slightly larger and brighter individual. Having recently become aware of the Whimbrel subspecies rogachevae and alboaxillaris (see previous Birding Frontiers post from 2016, Allport & Cohen 2016, Allport 2017) the bird was studied carefully.
In flight the striking pure white axillaries and underwings were seen, as well as a whiter rump and tail. The next day, Ernst Albegger was informed of the observation, which led to photographers looking for the bird and successfully securing some good photos.
Photos by Richard Katzinger (flight shots), Wolfgang Trimmel and Heinz Kolland (pictures of the standing bird) show many features of the subspecies alboaxillaris. The photographers are warmly thanked for their efforts to capture these images and the use of the photos in this blog post.
On the ground the bird appeared larger-bodied than adjacent phaeopus, and the overall paler coloration was evident due to the larger and coarser pale spots on the upper side as well as the reduced flank barring. The bird also has a paler face than adjacent nominate phaeopus, with notably paler cheeks, nape and supercilium. In addition, it appeared more dumpy or “potbellied” in shape. Note that the bird is relatively short-billed and so is probably a male, making the size contrast even more significant. Male Numeniini are smaller than females, some very markedly so in certain species, but amongst Whimbrel taxa sexual dimorphism is thought to be least prominent in Steppe Whimbrel.
Unfortunately there are no detailed photos of the complete vent and undertail area but it looks to be pure white insofar as can be seen in the images. The primary projection is difficult to judge from the photos but appears not to extend notably beyond the tail – as in the bird thought to be a female in Maputo – but is similar to the male bird in Maputo (DNA analysis has now confirmed the suspicion that that bird was a male).
Note that the very small area of visible tail edge in the photo below appears to show the correct ‘laddered’ pattern for Steppe Whimbrel, but it is the pattern of the whole tail span that is critical for sub-specific identification so, whilst this is consistent with Steppe Whimbrel it is not sufficient to fully support the identification.
In flight the bird shows a clear very pale underwing. Unfortunately the quality of the images are not good enough to be absolutely sure of the detailed axillary and underwing pattern but the characters look strongly consistent with alboaxillaris showing an apparently unbarred clean white underwing, grey-barred underwing primary coverts and contrasting dark wings tips (which ironically tend to show up more clearly in poor quality images of alboaxillaris). The rump looks to be very pale but again the images are not clear enough for detailed analysis.
What is also very nice to see in this comparison is another structural feature that fits alboaxillaris – namely the dumpy body shape. On the below images another feature is the barring of the inner primaries; alboaxillaris (top left) are banded inner five primaries significantly. In comparison, a normal phaeopus (bottom right) generally shows darker inner primaries.
Overall the Austrian bird is a very strong candidate for the form alboaxillaris; all the key features, insofar as they are evident, point towards Steppe Whimbrel. However we are still so early in our understanding of this form that it should still remain categorised as a strong candidate, as a bird which shows features of the subspecies alboaxillaris and we hope that in the future as we understand Steppe Whimbrel better we can assign this bird with a greater confidence.
This is a remarkable record in several respects. On the one hand, the world population of the subspecies is estimated to be <100 individuals, and on the other hand, this breeding bird is best known from the Kazakh steppes and the Orenburg region of Russia from where it is assumed they migrate to the coast of East and South Africa – a significantly more eastern migration. There are, however, specimen records of birds on passage from Hungary in the 1960s which have not been re-examined since they were first catalogued, and there was also a recent breeding record of alboaxillaris in European Russia in 2009 (Morozo & Kornev 2009), albeit in Orenburg, one of the very easternmost provinces.
This record in Austria is significant and may point to a more westerly breeding population, or it may be that as numbers have dwindled that Steppe Whimbrel have become mixed with the nominates. Either way, there is significant interest in finding birds in the ‘western’ side of the potential range. Christoph Himmel is planning surveys of migrating birds on the Azerbaijan coastline of the Caspian Sea with a specific target of finding Steppe Whimbrels. More on his proposed work is here, and you can support the research here.
Donating to the African Bird Club’s research fund is also a very valuable way of supporting this work too.
Thanks to the photographers Richard Katzinger, H. Kolland, W. Trimmel and Ross Hughes for permissions to use their photos.
Allport, G. 2017. Steppe Whimbrels Numenius phaeopus alboaxillaris at Maputo, Mozambique, in February–March 2016, with a review of the status of the taxon. Bull. Afr. Bird Club 24(1): xx-xx
Allport, G. & Cohen, C. 2016. Finding Steppe Whimbrel: discovery and identification in southern Africa. African Birdlife 4(6):48-54
Morozov V. V. & Kornev S. V. 2009. [Ornithological news from the Orenburg Oblast.] Russ. J. Orn. 18: 2069–2081. [In Russian.