Up to 60 lambs are to be fitted with tags
Newborn lambs have been fitted with radio tags to help investigate claims that sea eagles prey on large numbers of the young livestock.
The fortunes of 60 lambs are to be monitored from birth to weaning.
Crofters on Skye and in Wester Ross have claimed the UK's biggest raptors feed on their stock.
Radio tagging of lambs on two holdings in Gairloch, Wester Ross, has begun. Field workers will also observe the animals and eagles.
Scottish Natural Heritage (SNH) has appointed FERA (Food and Environment Research Agency) to do the study.
SNH said the study aimed to provide a scientific measure of the true level of lamb deaths directly attributable to sea eagles as opposed to other causes.
Each death will be mapped and the carcass traced and recovered to allow a post-mortem examination to determine the exact cause of death.
With an 8ft wingspan the soaring sea eagle is the UK's biggest bird of prey, followed by the golden eagle.
Hunted to extinction almost a century ago, their reintroduction began in the 1970s and since then a small breeding population has established itself on islands such as Rum, Mull and Skye.
More recently, the birds have been seen in north east Scotland and in February experts confirmed that one spotted over Cumbria and Dumfries and Galloway flew down from Fife.
The sea eagle was seen over the Solway coast near Carlisle and later above Annan in southern Scotland.
It prompted a flurry of activity among bird spotters to catch a glimpse of the eagle.