Ringing

An evening session at Badaan yesterday caused us to ponder a potential terminal point for the period or occurrence on passage of some species passing through Bahrain. The migration regarded as the "Spring" in terms of a European time frame has slowed to a crawl. The fields are largely bare of migrants leaving our resident species more visible than usual; however a few species including possibly even some sub species of others thought to have all ready passed continue to be observed and even netted. Yesterday three Garden Warblers in our nets if added to the glut of others recently trapped indicate that for this species, May is their main period of passage. The Orioles seen last week that were present in good numbers have now disappeared; having first arrived around the end of April mid May represents the terminal date for their occurrence in the spring. The Roller and Cuckoo seen last week had gone but observations of both these species have been prolonged and spread over the last few months. Last week we had a flush of Reed Warblers none this week or the week before, is this indicative of possibly a very short period for their movement through. Willow Warblers and Chiffchaff were both observed in good numbers last weekend however only a few fleeting glances yesterday of a few remaining birds gave note that they would not be seen again till autumn. However being some of the earliest species to arrive are these late comers a different population or sub species to those that passed before. With the variations between many sub species only slight, often with separation identifiable only in the hand, it is possible our and similar ringing campaigns in the Middle East will be able to determine and identify positively the species involved and provide the missing links to answer these questions.