On the 3rd October 2010, Horwich Moors regular Ken Haydock discovered a dead Ring Ouzel besides a six foot chain link fence which surrounds one on the mast buildings on the very top of Winter Hill, actually within Lancashire. Conditions preceding it's discovery had included days of complete cloud cover over the moorland at the top of Winter Hill with visibility very poor indeed and only three days prior to this find, I had flushed a female/immature ouzel from very close to the mast itself in just such dire conditions. With this in mind and the location of the corpse, it seems plausible that it had collided with the fence to meet it's most unfortunate demise. Ken left the corpse in situ but I subsequently discussed it with moors fanatic Andy Makin who sought it out, retrieved it and a few days later handed it over to me.
Whilst initially examining the corpse (on the bonnet on Andy's car, where in the photos below both photographer and on looking Makin can just be made out!) it was obvious that moult contrast was present in the greater upperwing coverts and that the tail feathers appeared quite pointed, both good indicators for a first-winter bird. The patent white crescent on the breast of our first-winter ouzel left us in no doubt that the bird was a male, but could a first-winter male really show such a distinct and pure white crescent? Ringing literature back at home confirmed my thoughts of covert moult contrast but the presence of such a blatantly adult like pure white breast crescent for a first-winter bird seemed to be covered by scant information at best. The Collins Field Guide (admittedly always going to be limited by space as to how much detail it can provide) illustrates a first-winter male as having a barely paler brown crescent and this was echoed by the vagueness of Svensson's Identification to European Passerines which states 'pectoral band invariably discernibly lighter than rest of underparts'. Most literature also stated that first-winter males have a paler throat with consequently more obvious dark lateral throat stripe (malar stripe) but 'our' bird did not and its throat was largely all dark but for a very small paler area on the chin. In fact, only Nils Van Duivendijk's Advanced Bird ID Guide offered some direction with the comment under first-winter Ring Ouzel of 'breast-patch rather distinct (in first winter male) to completely absent (in first-winter female) whilst The Birds of the Western Palearctic (Cramp et al.) depicts an illustration of a 'first adult male' with a similarly white breast crescent yet the text claims 'white chest band less distinct' (than a full adult male).
In fact, first-winter ouzels undergo a partial post-juvenile moult which includes the head, body, lesser and median coverts plus a variable number of inner greater upperwing coverts. Evidence of the wing moult can be clearly seen on the images below and this individual has obviously attained a rather adult male like breast crescent subsequent to it's body moult.
Above: Note the apparent pure whiteness of the breast crescent, of which a single feather has been displaced. The throat is all dark (save for a very small pale area on the chin) and completely lacks any lateral throat stripe (malar stripe).
Above: Note again the purity of the breast crescent and of course the intricate beauty of those underparts. The bill is all dark, lacking any paler base.
Above: Note the clear moult contrast in the greater upperwing coverts. The inners have been replaced with adult like feathers which are noticeably larger and more rounded with a pale edge on both webs and a very slightly barred appearance to their darker internal markings. The outers however are shorter and slimmer as we would expect from a juvenile. Their pale edges are confined to the outer web only, although here their internal markings vary from the entirely uniform ones described in Svensson's 'Identification to European Passerines'. The lesser coverts appear to have all been moulted whilst the median coverts show freshly moulted inners but older juvenile outers. Note also the 'scaly' upperparts, complete with quite broad pale fringes, apparently wider than those of adults (per. Birds of the Western Palearctic).
Above: Depiction of greater coverts from Identification to European Passerines (Svensson 1992) and of the 2010 Horwich Moors bird. (Ian McKerchar)
Above: The typically long primaries of Ring Ouzel are evident here and give rise to it's characteristic in-flight profile.
Above: The tail feathers appear rather pointed at their tips (although it is the central pair which are more important to view in this respect) whereas those of adults are more rounded.
Clearly, the ageing of Ring Ouzels at any time of year can often be fraught with a degree of difficulty and attempting to do so should be undertaken with caution in all but the most obvious or extreme of individuals. Adult females in spring/summer can appear very similar to the plumage of adult males and, as with this Horwich Moors bird, ageing autumnal males is not always as straight forward as it might seem, particularly with brief or poor field views only. Either way, I certainly learned plenty from this single corpse, one which will now reside in the collection at The Manchester Museum.
Svensson, L. 1992. Identification Guide to European Passerines.
Cramp, S. 1988. The Birds of the Western Palearctic. Volume V
Svensson, K., Mullarney, K. and Zetterstrom, D. 2009. Collins Bird Guide
Van Duivendijk, N. 2010. Advanced Bird ID Guide
Thanks to Ken Haydock and Andy Makin for finding and then retrieving the corpse respectively and to Paul Brown for his discussion on it's ageing.
Ian McKerchar, October 2010
BACK TO THE IDENTIFICATION ISSUES HOMEPAGE
BACK TO THE MANCHESTER BIRDING HOMEPAGE