Back on track

After a difficult start to her migration when she made a long overnight crossing of the North Sea from Scotland to Denmark, the juvenile female honey buzzard from Moray has made good progress south-west through Europe over the past three days and last night roosted in Belgium, a few miles from the Luxembourg border.

In our previous update the young honey buzzard was flying south over the islands of the Wadden Sea National Park on the Danish coast on the afternoon of 17th September. She crossed the border into northern Germany at 17:50 that evening and then settled to roost in a small wood between the villages of Büttjerbüll and Bordelum very close to the marshes of the Wadden Sea coast, having flown 237 km during the course of the day. 

Next morning she remained in the local area until 10:40, when she resumed her migration, once again following the coastline as she flew south. She made steady progress, and by the time she crossed the River Elbe at 15:10 she had flown 100 km from her overnight roost, flying at altitudes of up to 600 metres.

The young honey buzzard followed the Wadden Sea coastline as she headed south on 18th September

Half an hour later she was circling over the town of Bremerhaven where the River Weser reaches the Wadden Sea, and at this point, rather than following the coastline to the west, she continued south along the course of the river, before eventually settling to roost in a small wood in an agricultural area just north of the town of Brake at 17:37. She had flown 170 km during seven hours of migration, at an average speed of 24 km/h. 

The honey buzzard flew 170 km through north-west Germany on 18th September

On the following morning, 19th September, the honey buzzard left her roost site at 08:40. She crossed over Brake, before stopping again for just under an hour in an area of scattered trees and large gardens just to the south. She was flying again at 09:46 on a south-westerly heading, now diverting away from the course of the River Weser. An hour later she was approaching the city of Oldenburg. She skirted around the eastern side of the city, flying at an altitude of less than 100 metres, as she had done since leaving her roost.

Once past the city she maintained the same south-westerly course as before, likely influenced by an easterly wind of 19 km/h. At 12:37 she was flying at an altitude of 148 metres over the town of Cloppenburg and had now flown 70 km since leaving her roost. 

She continued south-west through Lower Saxony during the afternoon, soaring up to a maximum altitude of 634 metres. By 16:10 she was just five kilometres from the Netherlands border, and half an hour later she was circling over the town of Ahaus in the state of North Rhine-Westphalia in western Germany. She then settled to roost in a small wood a few kilometres south of the town after flying 188 km during the course of seven-and-a-half hours of migration, at an average speed of 25 km/h.

She maintained a south-westerly course throughout the day on 19th September, flying 188 km

Yesteday morning the young honey bizzard remained close to her overnight roost until 10:40 when she set-off south-west again. Her GSM transmitter was now sufficiently charged to enable us to collect 1 GPS fix every minute, which provides a very detailed insight into her altitudinal changes, as well as her route during the day. It showed that for the first 40 minutes she flew at low altitude, often less than 100 metres, but then as the temperature increased and thermal updrafts became available, she began soaring at higher altitudes, initially up to 200-250 metres and then from midday, up to 500 metres. At 12:40 she crossed the River Rhine and had by that stage flown 56 km in two hours since leaving her roost site, aided by a light north-easely tailwind of 14 km/h.

The GSM transmitter, which logged points every minute on 20th September, showed how the young honey buzzard exploited thermal updrafts during her flight south-west that afternoon (note she is flying right to left in the image).

She maintained the same south-westerly heading during the afternoon, and flew directly over the German city of Mönchengladbach between 14:20 and 14:40, flying at altitudes of between 200-400 metres. Then, as she crossed into Belgium at 16:20, the landscape would have begun to change as she approached the Ardennes mountains. She continued on the same south-westerly heading until just before 18:00 when she settled to roost in forested valley 5 km from the border with Luxembourg, having flown 232 km during the course of the day. Her faster average speed of 32 km/h almost certainly due to the north-easterly wind that provided tailwind assistance all day. 

A north-easterly wind enabled her to fly 232 at an average speed of 32 km/h on 20th September

It is now clear that after nine days of migration the juvenile honey buzzard has recovered from the difficult start to her journey, and, aided by helpful north-easterly winds, and perhaps having met other migrating honey buzzards en route, is now almost back on her expected path. She is likely to continue south into France and then Spain before, we hope, crossing the Strait of Gibraltar to Africa.