Friday, August 28, 2009

27th August, 2009

A really mixed day for weather with a light SW wind and almost calm conditions, increasing wind and rain half the afternoon and then sunnier times, ending with a wild wind and lashing rain in the evening.!

Seawatch counts over 2 1/2 hours showed bird numbers differ substantially from day to day with 2700 Manx Shearwater and around 600 Gannet moving today, no waders other than 2 Turnstone and virtually no auks again and passage finishing much "earlier" even though the conditions were better. Similarly virtually no Fulmar were on the move, but variety was provided by several Arctic Terns, Arctic Skua and Great Skua. Kittiwakes appear now to be moving as almost 60 went south, some being of mixed parties of adults with beautifully marked juveniles.

At home the sudden arrival of 2 Northern Wheatear and a Whinchat suggested some passerines were on the move too, as had happened yesterday with the brief appearance of 2 Common Whitetroat, young birds that were obviously moving together.

Having been hooked on migration since an early age details of what routes birds used , where they went and how quickly they completed their journeys was a mystery until the recent use of satellite technology. Ringing recoveries showed their presumed eventual destination, but even this was complicated by some species moving around significantly , e.g. Swallow, in their winter quarters. Fascinating details are now increasingly being revealed that takes us another quantum leap forward in our understanding of migration . A report yesterday relating to Eurasian Hobby, based on work carried out by Meyburg and colleagues , is no exception. Large numbers of Eurasian Hobby have been ringed but virtually no recoveries ever received. A bird fitted with a transmitter in 2008 in Germany left its breeding area in mid August and went south to the island of Elba, where it took a "week out". It then continued south into Africa into its winter quarters in Angola, the whole journey taking 49 days with the average distance travelled being 174 km. per day ( more if you take out the "rest week" ). Absolutely stunning and underlining the fact that even the Common Whitethroats moving through the garden at this time of year may be an appreciable distance away the next morning!! My utter and permanent conversion into being permanently in awe of this phenomenon happened many years ago. Spending time on the east coast of Yorkshire, at Spurn Bird Observatory, and witnessing the arrival of Goldcrests from continental Europe in autumn was an almost religious experience!! The fact that a little bundle of less than 5 grams could make that journey across the North Sea, with all the potential accompanying difficulties, turned me into the obsessive nut I am today when it comes to anything to do with migration!!!

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