Guest blog The SEA EAGLE: was its extinction justified? by John A. Love

Nurture 2023-09-01

Born and bred in Inverness, with a zoology stratum from Aberdeen, I managed the reintroduction of Sea Eagles from Norway to Rum 1975 to 1985, for NCC, and remain on the UK Project Team as an independent. Moved to South Uist as Zone Officer for SNH/NatureScot tent Uist, Barra and St Kilda 1992-2006. Retired to lecture on small trip ships virtually the world until present and written several books including ‘The Return of the Sea Eagle‘ ( 1983) and ‘A Saga of Sea Eagles’ (2013). Still living on South Uist.

Sea Eagle delivering a Barnacle Goose. Photo: Steve Duffield

The White-tailed Sea Eagle seems unchangingly to receive a bad printing these days, expressly during lambing time. It has never been denied that some eagles have killed young lambs – but we now know that this tends to be a local issue and in truth, despite all the media hype, it is quite rare. Furthermore, recent research has now shown that this is happening plane less nowadays than in the primeval days of the reintroduction. It must be wonted that if a Sea Eagle is seen eating at a lamb or sheep carcase it does not midpoint the eagle had killed it. And indeed, Sea Eagles have never been known to have killed an sultana sheep (nor cows which some have tried to claim!)

Although shepherds do not like to shoehorn it, sheep still die out on the hill from a variety of causes. A study by Dr David Houston, of crow predation in Argyll in the 1970s found that some 15-20% of lambs died, mostly in the first week of life. 254 lamb carcases were brought in by shepherds: 27% were still born, 9% were diseased, 5% had been unwittingly killed (crushed by ewe, strangled in fences, hit by cars, killed by dogs), 45% of them had worn-out fat levels and only 7% seemed perfectly healthy. Perhaps this level of mortality no longer prevails today and there is currently a study underway to examine such ‘black losses’ amongst lambs.

Adult sheep in poor condition can be attacked and killed by foxes, dogs or by gulls, Ravens or crows. Sea Eagles never peck the vision out, a track to who really had been the culprit. Although a bird of prey (and therefore equipped to kill) the White-tailed Sea Eagle is increasingly related to vultures – in habits as well as lineage. Indeed, stuff increasingly unreceptive to vultures than they are plane to Golden Eagles it is not surprising that Sea Eagles should be expressly fond of carrion. This was recognised by Robert Gray In his ‘The Birds of the West of Scotland’ where in 1871 he wrote’: ‘The senior supplies of [the Sea Eagle] appears to be stranded fish, procured in the vicinity of its maritime haunts, sufferer sheep found on the moors, and occasionally a salmon left by some scared otter – a selection increasingly in keeping with the innocent life of a vulture than the plundering habits usually ascribed to eagles.

I have scrutinised a lot of old books, collectors’ notebooks etc from those early days. They are important considering they were written by people with first-hand experience, at a time when there were still native Sea Eagles around. Professor William MacGillivray, brought up in Northton, Harris confirmed in 1886 how ‘at seasons of mortality among sheep, as in the end of autumn, when braxy commits its ravages, or at the end of spring, when severe weather often causes the death of young lambs, [Sea Eagles] are not uncommonly seen hovering about’.

Let us not forget that in the nineteenth century, during the Highland Clearances, many people were stuff cleared from their homelands to make way for increasingly sheep. Grasping landlords replaced their tenants with huge flocks of Blackface and Cheviots. The island of Rum, where I once lived and well-nigh whose human history I have written a book, was one specimen in point – and it was by no ways unusual. In 1826 and 1828 over four hundred islanders were shipped off to Canada, to be replaced by no fewer than 8000 Blackface sheep. Not surprisingly this wet, unforgiving and rocky island was quickly overgrazed and soon could not possibly support such numbers. The sheep walk never did make the expected profit, and the flock remoter dwindled. Rum became a sporting manor until, in 1956 the sheep were all gone, and the island was sold as a nature reserve.

Immature Sea Eagle eating Red Deer carrion, Rum.

This state of wires was worldwide throughout the Highlands and Islands so, given the Sea Eagles’ taste for carrion, we have to ask was its total extermination in the UK by 1916 really justified? The species was widespread here surpassing humans appeared on the scene. It was the Sea Eagles’ very fondness for uncleanness that was proving its undoing. It was accused of taking lambs, so poison baits were hugely destructive, later slantingly shooting and egg collecting.

It seems only right, in these enlightened times, that this magnificent bird should be when where it belongs. As part of a third reintroduction attempt, in 1975 (bringing birds wideness from Norway and to be released on the Isle of Rum nature reserve) I looked in detail at the history of Sea Eagles in Britain. Most of the old literature confirmed the Sea Eagle’s love of uncleanness (hence its fatal vulnerability to poisoning) but I was surprised to find such finance had less to say well-nigh the bird’s impact on lambs. Several communities plane went as far as to make the word-for-word opposite claims – that their local Sea Eagles never touched lambs. St Kilda, South Uist, the Shiant Isles and Fitful Head in Shetland were examples. I noted 141 prey items that had been found in Sea Eagle eyries by egg collectors etc. Only 12 (9%) involved lambs; and 7 of these were from a single nest in the Lake District. It is often difficult to tell whether lamb remains found in nests had been killed or found once dead. Certainly when then, with upper losses amongst sheep flocks for a host of reasons, there had been no shortage of uncleanness for Sea Eagles. And we now know that large, conspicuous items such as sheep, lambs and deer, unchangingly tend to be over-represented at nests, compared with fish and small creatures whose wreck could be ingested and – if not digested completely – were regurgitated later in pellets elsewhere.

I moreover found a remoter 46 observations of Sea Eagles feeding yonder from the nest, mostly in winter. But the old literature would imply that Sea Eagles were never as responsible for killing lambs as history later came to assert. Thus, it seems that nowadays some arch-critics of the Sea Eagles’ comeback are re-inventing the mistakes of the past. Sea Eagles are lazy hunters so readily find uncleanness as an easier meal. But still, it is stuff unsupportable that eagles seen feeding on sufferer sheep or lambs are unsupportable to have killed them. Sure, Sea Eagles can skiver small lambs but, at the end of the day, just how many shepherds have unquestionably seen it happen and are not merely making false assumptions based on others’ claims?

One study had taken place when in 2010 to investigate so-called lamb losses in the Gairloch area. It was here that, in 1900, Charles Dixon observed: ‘[the Sea Eagle] is a regular scavenger of the shore . . . Healthy vigorous birds or animals are seldom attacked by this eagle: it confines its attentions to the weakly and the wounded creatures that cannot move fast or offer any serious resistance.’ But in fact, the 2010 study found no lambs lost to eagles that season (however the complainants went on to counter that it was considering there were too many researchers around!) Mull was regularly seeming as a major problem zone for lamb kills in the early days, and it is here that some of the weightier studies have been undertaken ( by Mick Marquiss and colleagues). One nest in Mull did present a worst-case scenario, but only in one year over several studied. Of the 45 lamb remains taken by this pair in 1999, 21 were intact unbearable to show the rationalization of death and revealed that only 13 (or 62%) had been taken alive. Plane then, this suggested that this pair might well have killed a total of 30 all season. Rabbits had been scarce that year due to an older myxomatosis outbreak. In the year 2000 this pair moved to flipside nest nearer the tailspin where fewer lambs were misogynist and Rabbit numbers had recovered. That year, of 19 lambs examined in this nest only four (21%) showed signs of predation.

In 1999 it was found that a second pair had scavenged all but one of the 11 lambs examined; no data was misogynist the pursuit year since their tastefulness struggle failed. A third Mull pair investigated that year took whimsically any lambs despite having to fly over lambing areas to reservation seabirds on the tailspin 15 km distant. In 2001, at a nest in Skye with the highest total of lambs found, all had been scavenged and none had been killed. Local crofters there might dispute these results. But it is clear, from good science, that incidences of eagles killing lambs is very much a localised problem and not plane an yearly one. When, a decade ago, the study had been widened to include data from all the other Mull nests the yearly consumption of lambs, was in the order of 200, and most of them would have been scavenged rather than killed.

It was unscientific that Mull supported over 20,000 tastefulness ewes in total but the research had confirmed that numbers of lambs taken varied between Sea Eagle pairs, and from year to year, while some pairs never looked at lambs. Furthermore, the losses owing to eagles were small compared with other sources of mortality. Losses had minimal impact on the sheep economy of the island as a whole – though perhaps not on those few unfortunate crofters with an odd rogue pair of eagles.

Sea Eagle eyrie, 1995.

A study has now just been completed over several years, examining over 11,000 prey items recovered without the Sea Eagles’ tastefulness season, from no fewer than 92 variegated eyries. We now know increasingly well-nigh the nutrition of Sea Eagles than most other birds of prey in this world. White-tailed Sea Eagles have been known to take several hundred variegated prey species, working or dead. Seabirds, fish with Rabbits constitute the main nutrition of Scottish Sea Eagles. They moreover venery and skiver other predators of lambs – gulls, crows, Ravens plane the odd fox. Currently we have some 130 to 150 pairs of Sea Eagles now tastefulness in Scotland and Ireland. Norway on the other hand (where our original reintroduced eaglets came from) protects its Sea Eagles and now has 3000-4000 tastefulness pairs; rarely, if ever, do Norwegian sheep farmers wits any Sea Eagle predation on livestock. And we can’t seem to live with only 150 pairs!