12 February 2012

Steppe Gull Spread Wing - Sabkhat Al Fasl

I have found two dead Steppe Gulls in the last week, one was on my local patch, but I did not find it until late in the evening and the photographs of the spread wing did not come out well as the colours are not accurate due to the late evening light. By the next morning it had be taken, presumably by the resident Arabian Red Fox that lives very close by to where I found it. Fortunately for me, but not for the bird, I found a second bird at Sabkhat Al Fasl on Thursday. This allowed me to take a photograph of the spread wing in good light which is shown here.
Steppe Gull - Spread Wing

The features showing this is a Steppe Gull wing-tip pattern include the following:
·         Black markings on the primaries extend to P3 (counting primaries from outermost feather P10). This is often seen on Steppe Gull as well as Armenian Gull and Heuglin’s Gull but not in Caspian Gull where black generally only reaches P5.
·         Equal pale tongues are visible on P7 & P8. Tongues are longer in Caspian Gull and not present in Armenian Gull or Heuglin’s Gull.
·         Primary moult has finished on this bird which is normal for Steppe Gull (moult is still active in Heuglin’s Gull with P10 still growing and often P9 & P10 but is finished in Caspian Gull by January)
·         This bird has only one primary mirror, 10 – 44% of birds have a second mirror measuring 3-19mm in size on the inner web of P9
·         The dark on the wing is obvious but not as extensive as would be the case with an Armenian Gull. It is, however, more than would be expected for a Caspian Gull.
I would like to express my thanks to AbdulRahman Al-Sirhan (Kuwait) for discussion on this spread wing photograph.