At last weekend’s British Birdfair at Rutland Water we joined with Chris Packham to launch a new joint project.
Privately funded by a pair of extraordinarily generous and supportive philanthropists, this project has been in development since the New Year. We are grateful not only to our funders, but also to a number of people without whose help the project would have been a non-starter.
This year our project has focused on fitting satellite tags to young golden eagles across Scotland. At this stage we’re not announcing how many eagles have been tagged, or where, exactly, they’ve been tagged (the location of nest sites must remain confidential for obvious reasons), but let’s just say we’ve tagged a shedload. Here’s a small subset:
The tags were fitted in June and July by highly experienced & appropriately licensed fieldworkers, with the support of several landowners, some of whom came along on tagging days. All the tagged eagles have fledged successfully and they are all hanging out in their natal territories, as expected.
Researchers have been satellite-tagging golden eagles in Scotland since 2004. This new technology has revolutionised our ability to better understand golden eagle ecology, and particularly the birds’ early years of life when they leave their parents’ territory and wander around the country before they attempt to settle in a territory of their own and join the breeding population at between 3 to 5 years of age. For an excellent first-hand and simple explanation of how the technology works in practice, have a read of this blog written last week by Stuey Benn of the RSPB.
Understanding golden eagle juvenile dispersal behaviour has important conservation implications because at present, Special Protection Areas designated specifically for golden eagles are based on the number of breeding pairs present in a particular area, and not on the number of juvenile eagles present. Research on 36 satellite-tagged golden eagles, undertaken by Ewan Weston for his PhD (published in 2014), identified nine distinct areas, known as Temporary Settlement Areas (TSAs) where these young birds tended to spend a lot of time during certain months of the year. Here’s a map we’ve created, based on data published in Ewan’s PhD, of these nine TSAs.
The identification of these areas would have been virtually impossible without the use of satellite tags. The data collected from our tagged eagles will contribute to this ongoing scientific research to help determine the importance of these, and perhaps other yet-to-be-discovered TSAs, which may lead in future to some areas being newly designated / protected for golden eagle conservation purposes.
Of course, along with the invaluable scientific data generated by these satellite tags, showing us how golden eagles utilise different landscapes, we are also learning a lot about how one type of land-use, intensively managed driven grouse moors, is impacting negatively on the golden eagle population. This has been known for some time, but the recently published Golden Eagle Satellite Tag Review clarified in which particular grouse moor areas satellite-tagged eagles are being illegally killed or are ‘disappearing’ in suspicious circumstances.
When the Review was published in May this year, we created this map to show the significant clustering of satellite-tagged eagles that had either been confirmed as illegally killed or the tags had suddenly stopped working in suspicious circumstances and the tags and eagles had ‘disappeared’ off the face of the earth:
The clusters around the Cairngorms National Park, including the Monadhliaths to the NW and the Angus Glens to the SE, are all areas where the land is intensively managed for driven grouse shooting.
Interestingly, when you overlay these data of killed or ‘missing’ satellite tagged eagles on to the map showing the Temporary Settlement Areas utilised by juvenile golden eagles, this is what you get:
[Yellow stars = satellite-tagged eagles confirmed as illegally killed; red stars = satellite tags that suddenly stopped functioning in suspicious circumstances and the tag & eagle nowhere to be found].
It’s quite clear then, that in some driven grouse moor areas, particularly in the Angus Glens, the Monadhliaths, and the NE and SW areas of the Cairngorms National Park where young golden eagles are spending a lot of time, illegal persecution is an ongoing threat.
Obviously we don’t yet know where our tagged eagles will disperse to, and whether they might head for some of these dangerous TSAs, but we’re about to find out.
We’ll be providing updates on our eagles’ movements over the coming months and if the tag data indicate that any of our birds have come to any harm, we’ll first be reporting it through the proper channels to the Police and then we’ll be publishing appropriate details on this blog.