SARUM U3A
OCTOBER 2013 COFFEE MORNING
It was a full house to hear Steve Oakes’ talk “The magic of Bird Migration” and we were rewarded with a fascinating avian journey. Bird migration was first recorded in the Bible where Jeremiah commented on the annual flight of honey buzzards and cranes around the Mediterranean.
Scientific recording and analysis began in the 19th century when Hans Christian Mortensen wanted to know the destination of the large number of starlings soaring above him. He introduced bird-ringing, and this technique has helped to answer many questions. Wing tags, neck collars, radio transmitters, and satellite tracking have developed and refined the naturalists’ research.
How does a sedge warbler weighing 12gm survive a 6000 mile journey to South Africa, crossing the Sahara desert? In early September these birds consume vast quantities of aphids, doubling their weight, to make their one-stop journey via northern Spain. Swallows only fly by day, and eat on the wing. How does a cuckoo, abandoned by its mother, know how to migrate to South Africa? Is this genetic inheritance? Experiments with birds in registration boxes show that they may have a sun compass and are sensitive to ultra-violet light. Using a planetarium we know that night-flying indigo buntings navigate using the stars. Fledged blackcaps map their local area to return after migration to the same nest site.
Birds make these epic journeys to survive.
Steve’s animated talk and excellent RSPB images gave a vivid insight into the wonderful world of birds.