As temperatures plummet in Greenland, this goose makes an incredible 1,500km journey back to the UK to spend the winter. Since 1999, fewer and fewer geese make it here. WWT is working hard with others at GWGS (the Greenland white-fronted Goose Study group of dedicated volunteers) and NPWS (the National Parks & Wildlife Service, Ireland) to discover why.
Diagnosing why a species is in decline is often difficult and requires a major investment of time and money over many years, but in the case of the Greenland white-fronted goose it is particularly challenging. They breed in one of the most remote and hostile areas of the world and so studying them on the ground is extremely challenging. Their migration route across the great ice cap of Greenland, for example, is impossible to study through human observation alone.
Each year GWGS and WWT count the numbers of Greenland white-fronted geese that arrive on our shores. In the late 1990s Britain and Ireland hosted nearly 36,000 Greenland white-fronted geese but just 20 years later that number has almost halved.
We know that these birds fail to breed as successfully as other grey goose species, such as greylag geese, so the numbers of goslings produced in any year has struggled to keep up with mortality losses from the population.
Recently we have been looking at the effect that climate change is having on the snow conditions in western Greenland where they nest. It is thought likely that the conditions are hampering Greenland white-front breeding success because a warm spring can mean more snowfall in western Greenland. If snow covers key breeding and feeding areas, this can affect the timing of nesting attempts and in some years birds may choose not to breed.
Average reproductive success is generally lower now than it was in past periods. This could be a key reason why Greenland white-fronts are suffering such a dramatic decline. So we are using new technology to looki in detail at this critical part of their yearly cycle.
By 2009 it was apparent this flyway population was in steep decline. We joined forces with partners to produce an Action Plan that details the measures needed to save this charismatic bird. We have been working with wintering flocks across Britain, Ireland, and at their migration stopover sites in Iceland. The team has been catching, tagging, GPS tracking and x-raying the birds, to uncover the problems they face and the habitats they rely on throughout their incredible journey.
Since 2012 we have fitted over 100 white-fronts with GPS collars. From 2016 onwards these collars have also incorporated accelerometers which allow us to decipher the behaviours of the birds as often as every 5 minutes 24/7. The live updates on each individual bird’s location and behaviour are received through the mobile phone network. They weigh 25-30g, which is less than 1% of their body weight during migration.
With the extremely detailed GPS and matching behavioural data, from my desk in Scotland I can tell exactly when, down to the nearest few minutes, a bird laid its first egg or settled down on its nest to start incubation, even though it was in a remote valley inhabited by Musk Ox on the west side of Greenland thousands of kilometres away...
Larry Griffin, WWT researcher
The information that we get back from each tag gives us a detailed understanding of each individual’s daily life and allows us to establish whether or not a female attempts to breed and at what stage during incubation or chick rearing she fails. We have now x-rayed 100 birds that winter in Scotland plus a sample from Ireland, with plans to increase this number over the coming winters.
The data from these x-rays and our tags shows that there is still an unacceptably high number - considering their full protection along the flyway - being illegally shot and either dying outright or being crippled and carrying the shot for many years with unknown effects on their future survival and reproductive performance.