22 June 2011

Common House Martin, Asian House Martin or Hybrid?

21/06/2011 – Dhahran Hills

Whilst bird-watching at the percolation pond I noticed a group of four Barn Swallows and a martin which were late for the species. I have not seen a Common House Martin in Dhahran since the 20th May and this was a month after the previous one. The martin looked slightly odd as, although distant it appeared to have a very dingy appearance including the rump. I gradually got closer to the bird and took a few photographs although this was second to trying to get details on the bird in the field. Unfortunately the martin was on its own with no other martins to gauge size on. At close range, although in evening light, the bird did not look clean as all the previous Common House Martin have looked that I have seen here. The most striking thing was the pale rump appeared very small for a Common House Martin and also was not white but had a slightly dirty wash (possibly slightly orange?). This combined with the brownish washed throat, under-wing coverts and under-tail coverts and paler although not white belly gave the bird a distinct but not typical Common House Martin appearance.
Thoughts then turned to Asian House Martin, due to the restricted pale rump, although the bird did not fit my recollection of these birds. Size was not possible to tell as it was only with Barn Swallows and I could not see any dark feathering below the bill on this bird despite watching it for maybe 30 minutes until it became too dark. The bird had brownish under-tail coverts which I remember was a feature of Asian House Martin but had a dusky wash across the throat which should be white in Asian House Martin. The under-wing coverts, although not as pale as on some Common House Martin, were not as dark as on Asian House Martin and are not darker than the rest of the under-wing. The tail fork was also not easy to assess as the bird had quite worn plumage but the bird did not give me the impression of having a particularly short (squariesh ended when spread) tail. Asian House Martin has not been recorded in Saudi Arabia.
Another possibility is that the bird is a hybrid Common House Martin x Barn Swallow or similar? Many of the features fit this well as it structurally looks quite like a Barn Swallow and would probably have longer tail streamers if they were not so abraded. It also has a clean cut throat pattern with a buffy throat and greyish boarder that many Barn Swallow hybrids have. Hybrid Common House Martin x Barn Swallow is rather common in Italy apparently.

A point to note here is that hirundines in the Middle East can become stained due to oil – see earlier post on the website about the subject (Unusual Hirundines – May 2011). This, however, does not look the case with this bird as the throat and under-tail coverts are the darkest and belly the palest.