Feb 2022
by Matthew Wilson

The early years of monitoring throughout the 1980s was mainly under contract to RSPB when my 'beat' was from the North coast of Knoydart to the Sound of Mull and into the Great Glen. In those days there were far fewer sea eagles and the release programme was still underway.

The male is wing tagged White 'L' who was hatched on Mull in 2007. Most of the wing tag has now broken off but in certain lights you can see one small remainder of the tag folded over on the left underwing. The tag on the other wing came off completely some years ago. The current female is untagged and has no leg rings, as was her predecessor. The females changed in 2017. As the original female was 'unmarked' it is impossible to say what happened to the original female.

The original birds paired up in 2010 and I thought that they fledged their first chick that year. This was not confirmed as the tree wasn't climbed but the prey remains and activity at the nest suggested that there was a high likelihood that this new pair bred successfully. The original pair reared a further two single chicks up until 2017 when this original female was displaced. The chick in 2016 was found dead under the nest at 6 weeks old. The weather had not been particularly windy and there were a lot of prey items in the nest. A new non-breeding female with a broken wing feather had been seen causing hassle at the nest site. It is pure conjecture but it is possible that the chick got knocked out of the nest in one of these skirmishes. It was this female who then took over as the resident female. These unusual occurrences have been observed at sites elsewhere. The chick from 2014 went East to pair up at Abernethy, Inverness-shire where she is currently successfully breeding. She was at the nest site last week. The new female who turned up on Eilean Shona in 2017 bred successfully with White 'L' in their first year and have done so every year since then. (5 single chicks).

Every year when the chick is ringed with a BTO and Colour Ring, the nest is checked for prey remains to record diet. Unless freshly brought in, smaller items like some fish species disappear quite quickly and recorded remains of prey tend to be bones, feathers, scraps of hide or skulls. Up until ringing, which is generally in June, this pair of sea eagles prey on a wide variety of species. Flounders, dogfish and mackerel remains are often found plus a variety of seabirds including fulmars, gulls, ducks, shags and tern fledglings. Only two remains of lambs have ever been found in the nest and one common seal pup remains. Judging by the skull and normal weight of a seal pup it is possible that this was a still born pup which had been scavenged but it is impossible to say with certainty.

I have been monitoring sea eagles since 1984 and Eilean Shona is one of my favourite places that I visit. It is always a privilege to do so and I am always very grateful for your permission and your continued interest in this breeding pair.