The evocative calling of geese crossing autumn skies encourages birders and non-birders alike to gaze upward. Some will ponder on where these straggly skeins are going, some may wonder what kind of geese they are?
I think of the lead bird and marvel at the navigational skill that it shares with the more experienced in the flock, that take their turn in forging the way ahead by creating an aerial wake to make the passage of the following birds marginally easier.
The constant calling as they make their way, especially useful in misty mornings, can’t just be juveniles asking if we’re there yet or back-seat drivers arguing about the quickest route.
The geese we most commonly see are not on long distance migration although of course some may be. These are Pink-footed Geese on a daily commute to and from feeding and roosting areas. They come in their thousands from the Arctic lands of Greenland, Iceland and Svalbard and are our most abundant winter visiting geese.
At the other end of the number spectrum are Taiga Bean Geese, a mere 200 of which choose to overwinter with us in Scotland, making them the UK’s rarest regular wintering goose. Typically, they arrive on the Slamannan plateau near Falkirk in late September/early October and stay until February although climate change is creating an ever-shortening sojourn.
Thirty-five years ago, another migrant arrived in Falkirk! Angus Maciver: a birder known to many in the SOC. He took an interest in this internationally important wintering flock and helped develop a study area that had been created by RSPB, John Simpson and others.
In time this interest matured into the creation of a small body called the Bean Goose Advisory Group (BGAG) comprising NatureScot, the RSPB, Forestry and Land Scotland, Scottish Agricultural College, Falkirk and North Lanarkshire Councils, and other interested partners.
We try to encourage feeding and roosting areas free from disturbance with the support of local landowners. We also undertake to improve our understanding of the birds both here and in their breeding area and migratory flyways.
In the beginning little was known about where ‘our’ birds came from and how they got here (indeed BirdFacts state that they breed in Lapland!); however, after gathering ringing and tracking data over the last fifteen years, we now have a more complete understanding of their annual movements. In the main, the Scottish flock breed in Dalarna County, central Sweden. Interestingly, the birds follow one of two separate flyways en route to us. One group stages in south-eastern Norway as they move south before flying directly to Great Britain. The other group stop to feed up in south-west Sweden, then moves to Jutland (Denmark) before crossing the North Sea. See Fig 1.
Fig 1: Map of the two flyways (click on the image to enlarge it)
This September, to help us better understand these migration routes, a small group of BGAG members followed our lead bird (Angus) on a flying visit to the staging areas.
Three main objectives were set for our mission: i) to see if we could positively identify ‘Scottish’ birds in migratory flocks; ii) meet our counterparts in Sweden and Norway to share knowledge and benefit from their experience; iii) attempt to establish productivity rates for this season.
Ringing birds provides invaluable data on life expectancy and productivity. During this last breeding season, we had two operational GPS collars on breeding females. Data from these devices confirmed that both birds sat on clutches but both breeding attempts failed. One bird was probably predated at the nest site and the other left her nest site after four days of brooding. Breeding grounds research remains the weakest area in our understanding of the Taiga Bean life cycle.
Productivity rates are low, and our best estimates come from juvenile counts after the Scottish winterers arrive at Slamannan. Anyone interested in this subject can find more information in the downloads section of our website at Scotland's Bean Geese - Downloads.
BGAG members with Dan Mangsbo (standing centre)
Objectives i) and ii) were achieved with the assistance of Dan Mangsbo in Sweden and Simon Rix in Norway. Flocks found by our country hosts contained birds collared and ringed in Scotland which was heartening to experience, however viewing conditions on moving water or birds up to their oxters in stubble rendered objective iii) unachievable.
Time constraints and distances to cover made our trip more of a Scandinavian rally with occasional bird watching! That said, we were privileged to spend time with a juvenile White-tailed Eagle (also watching the geese!). We detoured to catch up with some Common Crane - we got distant views but those were more than made up for with terrific views of Hobby, Marsh Harrier and soaring eagles. On arrival at our Norwegian cabin in the woods a pair of Black-throated Divers were on the lake to welcome us, and on our final evening a Black Woodpecker came to the garden as we sat on the veranda chatting about our adventure.
Footnote:
Our flight home from Gothenburg to Edinburgh took 1 hour 30 minutes; 23 days later the geese followed. The Norwegian contingent crossed the coast west of Kristiansand in benign weather conditions but 40 miles or so into their migratory flight they encountered a strong northerly airflow. This forced their passage further south from their original Fife Ness heading and they made landfall just north of Whitby, North Yorkshire. You might think that after an eight hour battle with crosswinds they might touchdown in a quiet grassy field in the Dales and rest up for a while, but no. They immediately turned north to follow the Pennines, not the coast, all the way to sunny Slamannan with only a brief water stop at Burnhope Reservoir in Upper Weardale. Total journey time of 22 hours. More information on the autumn migration including the route map can be found on Angus’ Beangoose Blog at beangoose.blogspot.com.
Quick reminder for anyone coming to visit the geese, please follow the advice in the SOC’s ‘Where to Watch’ app. Thanks.
W.A. Thomson
Images © Billy Thomson
