Thread by @IrelandsEnviro

Sea-eagles and hill lamb losses: Today I’ll talk about one of the most headline-grabbing suspected causes of lamb losses- predation by white-tailed eagles, often known as sea eagles, the UK’s largest bird of prey. 1/13

Like in Ireland, sea eagles went extinct in Scotland during 1916 following sustained persecution and egg collection. They were reintroduced in three phases: 1975-1985 Isle of Rum 82 eagles released, 1993-1998 Wester Ross 58 released, and 2007-2012 Fife 79 released. 2/13

The population has been steadily growing, with an estimated 150 pairs and an unknown number of juveniles. Their diet is very species diverse, reflecting the fact that sea eagles are considered generalist predators and scavengers. 3/13

However, individual pairs of eagles can become specialists in certain prey species, with Marquiss et al., (2004) noting that only three species, northern fulmar, rabbit and lambs, made up over half of the items collected in some nests. 4/13

The sea eagle remains a contentious issue, with many hill sheep farmers and crofters reporting that losses due to predation have increased with the ever-growing number of breeding pairs in recent years. 5/13

The first half of the nestling period coincides with the main lambing period in western Scotland. Lambs weigh about 3kg at birth and by weaning they will have increased to about 25kg, and so any dead lambs at this time would need to be dismembered to be brought to the nest. 6/13

@nature_scot Sea Eagle Management Scheme aims to reduce the number of lambs lost to eagles through measures like extra shepherding and trialling scaring devices. It supports those who have adapted their system to mitigate lamb losses like changing lambing location. 7/13

I will analyse flock management and lamb losses from farms and crofts in the scheme. The data will be used to investigate the role that sea eagles are playing in lamb losses, and what prevention and mitigation measures are being used by the participants to reduce losses. 8/13

I also have data from nest clearance work carried out as part of the scheme. This data can be used to find the dietary breadth of sea eagles, as well as the minimum number of lambs. Unfortunately, it is usually impossible to tell if these lambs were predated or scavenged. 9/13

The flocks in my study are all located close to active sea eagle nests and the farmers and crofters have reported losses to the eagles. We are hoping to collect prey remains from these nests to determine what the eagles are feeding on, however bird flu may prevent this work.10/13

Sheep farming can, and does, coexist with the presence of sea eagles elsewhere, such as in Ireland, Norway and Greenland. The situation in Scotland highlights the importance of stakeholder engagement in species #reintroductions and #rewilding. 11/13

Had these issues been predicted early on, mitigation actions could have been in place to prevent or reduce lamb losses. A recent example of excellent stakeholder engagement was the Lynx to Scotland study treesforlife.org.uk/lynx-to-scotla… 12/13

With growing appetite for species reintroductions and rewilding across the UK and Ireland, we need to carefully consider what impacts these species may have on those working the land, ensuring schemes are in place to protect their way of life or secure a just transition. 13/13