Marko's Nesting and Wintering in 2007

21. březen 2008

Marko spent the whole spring and summer in his nesting territory. Location data show that he hung around his familiar part of river Taats. Some locations point directly to his nest. We assume that he probably successfully nested in 2007. Available albeit scarce data suggest that he behaved in a similar manner as in 2005 and 2006, when we could watch him successfully breed his young.

He set off for the south some time between September 29 and October 4, 2007. He passed the same points along the route as in the previous years, reaching the wintering grounds between October 25 and 27. His migration, whose timing was similar to 2005, took 22 to 29 days.

Marko spent most of the winter on "his" island in Brahmaputra. A detailed view from Google maps shows that the river created a broad, most likely gravel-send bed with many streamlets in this area. When the river raises due to melting snow in the Himalayas, the riverbed changes substantially due to erosion and accumulation of gravel deposits. These "rivers-gone-wild" regularly cut new channels and create new islands on the deposits. Marko's data for all three winters (2005/6, 2006/7, 2007/8) overlap closely with a common central point. He always stayed in this place until the beginning of February when he flew on to one of the smaller tributaries some 100 km to the east, closer to the foothills. Despite a lack of data (especially in 2007) we can see a very regular migration pattern each year: February 4 - 6, 2006, February 6 - 16, 2007, January 30 - February 5, 2008 (the former date of each interval means the last day the stork was certain to be on the island, the latter denotes the first appearance in the other wintering area). His departures in the previous years (March 27 or 28, 2006, between March 23 and 28, 2007) suggest that Marko will stay there some more time before setting off for home. It remains to be seen, though, whether we will be able to get that information because the battery in his transmitter is almost flat.

autor: Lubomír Peške
Spustit audio