10 April 2012

Northern Wheatear – Dhahran Hills

A study using light-level geolocators, has recently demonstrate that Northern Wheatears from Alaska migrate to overwinter in northern sub-Sahara Africa, mainly in eastern Africa (Sudan or Uganda/Kenya). This migration route takes birds across the Arabian Peninsula, with birds travelling approximately 14,500 kilometres each way. These journeys, last up to three months in autumn and two months in spring, depending on breeding location and result in mean overall migration speeds of up to 250 kilometres a day (Bairlein et al). The study showed Northern Wheatears used a route further to the north of Dhahran in the autumn, through Kuwait and Israel, but came right across the Eastern Province area near Dhahran in spring. This agrees with the status of the species in the Eastern Province, with birds being seen more commonly in spring than autumn. The sub-species involved, according to this paper, is Oenanthe oenanthe oenanthe although these birds were named O. o. oenantoides by Portenko, but this name was later ignored by subsequent authors. Little is known about the Siberian/Alaskan birds, although they cover the greatest distance of any Northern Wheatear so probably have long wings and a larger size than the European birds? as pointed out by Norman Deans van Swelm.
Northern Wheatear (male)

The above photograph is probably of one of these birds, a male in full breeding plumage. The photograph was taken in Dhahran in March 2011 and they crtainly look large but without direct comparison to European Wheatear it is difficult to judge. Brendan Kavenaugh has caught a few Noorthern Wheatears in Bahrain and it will be interesing to see what his measurements show when I have the oportunity to see them.
Bairlein, F., Norris, D.R., Nagel, R., Bulte, M., Voigt, C.C., Fox, J.W., Hussell, D.J.T and Schmaljohann, H. 2011. Cross-hemisphere migration of a 25 g songbird. Biol. Lett. doi:10.1098/rsbl.2011.1223. Published online