Scotland's seabird populations decimated in recent survey

The data was gathered during annual monitoring surveys by the conservation charity’s staff, and groups it supports on its islands, to measure the health of the seabird population in its care.

The seabird breeding season runs from April to September, and with over 1 million seabirds nesting at National Trust places every year, the conservation charity has recruited additional staff to work on new initiatives aimed at protecting the country’s natural heritage.

Two new ecologists, James Crymble and Liz Morgan, have joined the charity to help rangers complete the annual monitoring surveys and record vital data about the seabird species that breed in Scotland.

Mr Crymble says that despite the low breeding numbers being reported in many places, there is still some positive notes to highlight.

He said: “Preliminary results are in from our rangers recent monitoring surveys and though numbers do seem to be down for many species, it is not all doom and gloom.

“Kittiwakes, which had undergone dramatic population declines in Scotland over the last 30 years, appear to be bucking the trend this year with numbers increasing at most of our locations.

“We suspect for some species that part of the reason for the poor breeding season may be a knock-on effect from the avian flu that has been having a devastating impact on Scotland’s seabird populations in recent years.”

James and Liz have recently been working on St Kilda carrying out vital seabird monitoring research alongside the Trust's other seabird rangers and researchers. (Image: National Trust for Scotland)

Ms Morgan said: “Some of these declines in seabird numbers such as Great Skua can be put down to the impact of avian flu over the last couple of years, but other things will also have impacted population numbers and nesting activity this year too."

The news comes a few months after the National Trust for Scotland warned that rare seabird colonies living on the remote islands of St Kilda face ‘disappearing forever' in the face of climate change. Ms Morgan has suggested that the weather has contributed to the low population.

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She added: “We suspect that the drop in numbers may be due to poor conditions experienced by birds over winter, such as stormy weather, which makes it hard for them to feed, and a lack of food more generally. Seabirds will sometimes take a ‘sabbatical’, taking a year off from having chicks, especially if they are not feeling at their best, which may be the case for some birds this year. So, there is hope things will improve next year.”

The surveys carried out so far on bird population cover the Trust sites of Canna, Fair Isle, Iona, Mingulay, Staffa St Abbs, St Kilda, and the Treshnish Isles.

Shag populations have declined dramatically on Canna, St Abbs, Staffa, and Treshnish Isles, in some cases dropping by more than 70 per cent compared to last year.

The Canna ringing group reported that no Fulmars have bred there this year, with numbers dropping from around 600 pairs in the early 1990s). Guillemots are also having a particularly bad season, but Puffin and Kittiwake appear to be stable.

Fair Isle Bird Observatory monitoring results indicate Fulmar numbers are increasing making it larger now than St Kilda, which has traditionally been the largest Fulmar colony in the UK.

St Kilda reported that Kittiwake breeding numbers are at their highest since 2008, Gannet numbers are low due to the avian flu, while numbers are similar last year for Skuas, Fulmar, Guillemot, and Razorbills.

On St Abbs, Herring Gull numbers are up slightly, and productivity is being monitored for the first time this year.

A Gannet nest on the isle of St Kilda (Image: National Trust for Scotland)

Guillemot and Razorbill numbers are down by 23 per cent and birds have been seen with unusual plumage variation. The Gannet population is going from strength to strength, with an increase of 24 per cent this year and Kittiwake numbers are also up by 9 per cent. Fulmars are stable with numbers similar to last year.

Counts undertaken by the Treshnish Isles Auk Ringing Group (TIARG) report there have been marked increases in breeding numbers since last year for Razorbill, Fulmar, and Puffin. However, there has been a 74% drop in Shag numbers compared to last year with some key absent nests.

All species are down in numbers on Iona.