Mingulay seabirds’ strong season

The Outer Hebridean island of Mingulay has had its best seabird season since 2000 according to new figures from the Trust.

Scotland’s largest conservation charity has been monitoring seabird populations on Mingulay since it became responsible for the protection of the island. The summer of 2017 has been a bumper season for razorbills and guillemots. The population of guillemots reached over 19,000 this year - an all-time high.

Razorbills

The charity cares for some of Scotland’s most significant seabird nesting sites, including St Kilda World Heritage Site, St Abb’s Head National Nature Reserve and Fair Isle, which are home to over a million seabirds every summer.

Over the past few years, the charity has been highlighting concerns about the future of the kittiwake, which has been in serious decline at all of its sites. This year there is some cause for optimism as the populations increased slightly at both Canna and St Abb’s Head: 4,803 were counted at St Abb’s Head, up from 2,779 last year but still well below the historic level of over 17,000 in 1990.

Another species for which there is serious concern is the vulnerable Leach’s storm petrel - St Kilda is the largest colony for this species in the north-east Atlantic. To try to understand the reasons for recent declines, 47 nest boxes have been installed, with three chicks hatching this summer. Wild weather conditions in early summer made it very difficult to monitor other seabirds on St Kilda.

Leach’s storm petrel chick

National Trust for Scotland Senior Nature Conservation Adviser Dr Richard Luxmoore said:

“Some species have had a really strong season this summer at sites across the country. However, we remain very concerned about the long-term plight of the kittiwake which, despite a more successful season at a few locations this summer, continues to decline at an alarming rate.
“It is always difficult to disentangle the many factors at play here and change in the availability of prey is often implicated. In the case of kittiwakes and puffins, which feed largely on sand eels, the long-term trend has been linked to the inexorable rise in sea temperatures caused by climate change, which is obviously a real concern.”

On Canna, the impact of the rat-eradication programme that was completed in 2006 seems to be having a positive impact, particularly for ground- and burrow-nesting species such as guillemots, razorbills and Manx shearwaters whose populations are all showing signs of recovery. There are now thought to be around 20 shearwater nests, up from a tiny handful in 2000.

Scotland is internationally important for its seabirds, having some 45% of the breeding populations in the whole of the European Union. The National Trust for Scotland hosts almost a fifth of these at its properties of St Kilda, Mingulay, Fair Isle, Canna, St Abb’s Head, Iona, Staffa and Unst.