Morphological variation of the saker (Falco cherrug) and the implications for conservation
The saker (Falco cherrug) is a traditional and valued bird of Arabic falconry. Harvesting birds from the wild raises questions of its conservation status and sustainability. The external morphology of this species is highly variable and the Arabic system of classification identifies over 11 saker ‘types’, some of which are more favoured among Arab falconers than others. Our study assessed morphological variation of birds chosen for known natal origin. Although most variation was between individuals-within-regions, the remaining variation in size and plumage characters may be appropriately described as a gradual cline between small dorsally uniform brown sakers from western lowland regions (e.g. lowland Kazakstan, and south-west Russia) to large, dorsally barred russet, dark brown and grey coloured sakers from eastern highland regions (e.g. south-east Russia, Mongolia, and China). Between these extremes exists a plethora of highly variable and contiguous populations. Although preferred falconry types may originate from any of these populations, the preferred ‘jarudi’ and 'sinjari’ sakers from northeastern Altai, Tuva, and Sayan populations, and the large sakers from eastern populations may be over exploited through trapping. The demand for wild sakers, however, may be substituted by an increasing number of captive bred falcons used for Arab falconry.