Golden eagle satellite tracking (Scotland)
Tracking golden eagle dispersal via satellite
Juvenile golden eagle
fitted with a satellite transmitter
Golden eagles are long-lived birds that do not reach maturity until their fourth year. Much is known about their ecology, but this concentrates on established breeding birds. Next to nothing is known about their ecology whilst they explore large areas of the uplands prior to becoming breeders.
Conservation and management decisions are made about golden eagles and other long-lived species that are focused on territorial pairs and use information from breeders. Obviously, this breeder-centric approach does not give us the full story, and our ignorance about golden eagle movement and ecology prior to them becoming breeders may undermine their long-term conservation. For example, upland development (e.g. windfarms, forest plantations, etc.) often takes into account the local breeding golden eagles. However, some areas that may not be important to breeding golden eagles may be important to non-breeders. The lack of information on non-breeders undermines the ability to site these developments wisely. It is true that established breeders should be a conservation focus, but by ignoring the requirements of younger birds, long-term conservation objectives are undermined.
Since 2004, Natural Research staff have fitted golden eagles with long-lived satellite-received radio transmitters (PTTs). These allow us to track birds during the first years of their life, giving us a first insight into their movements and what habitats are of importance to them. Their movements may highlight the importance to pre-breeding eagles of open areas in the uplands that are not within the home range of territorial eagles, thus affecting the way these areas are seen in terms of sustaining a healthy golden eagle population.
To date we have tracked over 30 young golden eagles in the months following fledging. Some examples (below) of the movements carried out by young eagles illustrate that after dispersing from their natal home ranges, golden eagles in Scotland can travel over a very large area. We are interested in the length of time that young eagles spend in their natal territory before dispersing, the movement strategies they use during their first few years of life and the areas they visit. This information should be of use to our understanding of dispersal processes, particularly of large raptors as well as being of benefit to conservation organisations within Scotland. Currently, we are tracking several golden eagles, which were hatched in 2008, 2009 and 2010. We will be fitting many more satellite transmitters to golden eagles in the next few years to better understand this important, but poorly understood stage in their life-histories.
Natural Research is committed to finding out more about the ecology of non-breeding eagles. In October 2009 Ewan Weston started a Natural Research co-funded PhD at the University of Aberdeen looking at the dispersal ecology of juvenile golden eagles in Scotland. This and other initiatives aimed at gathering more data are on-going. Click here to have a look at the way we are using DNA to monitor turnover of breeding eagles in Scotland. We are also carrying out a similar project in conjunction with several other organisations looking at dispersal of white-tailed eagles in the re-introduced population on the west coast of Scotland.
Please follow this link to see the first paper produced from Ewan Weston’s PhD http://www.biomedcentral.com/content/pdf/1472-6785-13-42.pdf
For more information about golden eagle satellite tracking, please contact info@natural-research.org
Photo: E. Weston