Shiants episode seven: An enchanting summer
Welcome to the seventh instalment of our work on the Shiant Isles Recovery Project from Iain Maclean. The project is an initiative to remove non-native black rats from the isles in order to provide safe breeding sites for Scotland’s globally important seabird colonies. It is part funded by the EU LIFE+ programme and is a partnership between RSPB Scotland, Scottish Natural Heritage (SNH) and the Nicolson family, who have been the custodians of the Shiant Isles for three generations.
In our last instalment we filled you in on the survey work that had started on the islands and now with autumn on its way Iain, a research assistant in the project, reflects on his summer spent on the Shiants.
Our seabird surveys carried on throughout July and early August much as they started; puffins, guillemots, razorbills and shags were all monitored for chick productivity and it has been a real pleasure to see the chicks develop from small downy balls of fluff to adult size. Although the numbers have yet to be analysed it seems (fingers crossed!) like a good year for seabird productivity on the Shiants. Sitting in the late July night twilight and hearing the calls between adult razorbills and their newly fledged chicks has been touching as has seeing puffins arrive with mouthfuls of sandeels to provide for the thousands upon thousands of hungry chicks.
It’s been exciting to see the Shiants so full of life this summer. We’ve witnessed an abundance of birdlife, cetaceans and some memorable otter sightings. Most days diving gannets can be seen all around the islands and curious seals are an ever present enthralling accompaniment to our work on the coast. It’s a reminder that while the removal of the rats will have positive effects on the seabirds, their continued survival is also linked to the health of the surrounding seas.
On the coast lots of young oystercatcher chicks have grown steadily to adult size alongside a smaller number of more hidden common sandpiper chicks. Large waves spill over the causeway at high tide, where we watched the young eider chicks catching food in the surf. Despite being hit by wave after wave these young birds always seem to bob back up to the surface unharmed, and seem truly at home in the sea. Among the rocks the shags seem to be having a good year: upon leaving the island many of the chicks were close to fledgling, and had started to scold us in a threatening manner much like the adults have been doing all summer.
On the top of the hill many bonxie chicks were approaching adult size, and the birds are impressively fast and powerful as they chase auks across the causeway. The bonxies also seemed to enjoy pulling apart our invertebrate traps in their spare time! Large flocks of twite would gather on fence posts and young meadow pipits, wheatears and pied wagtails also bumbled about, not quite as cautious of our presence as their parents. It was incredibly special to see a pair of peregrine chicks flying above the island regularly testing their powers of flight.
During July the islands were host to the annual visit of the Shiants Auk Ringing Group. This dedicated group arrive every year in order to catch and attach identifying rings to the legs of the seabirds. Once ringed the movement and lifespan of the bird can be more easily monitored, revealing valuable information which aids in conservation efforts.
Tagging along with some of the ringers outings was a great experience, and the enthusiasm with which the group goes about their work was energising during a wet and cloudy week on the islands. Although the group works with many different species, the highlight for me was the storm petrels. Setting a loudspeaker next to nets during the Hebridean twilight, storm petrel song was played luring in many of these small ethereal birds. The storm petrels seem to appear out of the night, fluttering excitedly around the speaker and occasionally flying around us.
Our more regular storm petrel loudspeaker lures, playing each night over the summer months in order to encourage the birds to nest, have also been popular with the petrels. While no evidence of nesting was found this year we’re confident they will be breeding here in the near future.
Much of July was also spent surveying the botany of the islands. It’s one of the pleasures of this work that we have had the opportunity to carry out such varied surveys – invertebrates, plants and birds. Identifying plants requires you to get up close to the ground and really gives you a different perspective on the island. An area of ground scarcely noticed on our way to carry out bird surveys upon closer inspection becomes rich and fascinating, with many different elegant grasses, tiny mountain flowers stretching out in abundance, and a whole diverse range of fascinating insect life roaming through what to their scale must seem like a vast forest. On sunny days many blue butterflies were found along the coastline. These surveys will allow us to monitor how the flora and invertebrate species of the Shiants respond to the removal of the rats.
So all in all it has been a great summer, with a lot of enjoyable work, much time appreciating the amazing beauty of these islands and hopefully a successful year for wildlife. It is humbling to have been a small part in this story over the summer and I hope it can lead to the islands being a secure haven for more of Scotland’s fragile seabird populations.
The Shiant Isles Recovery Project is a partnership between RSPB Scotland, Scottish Natural Heritage and the Nicolson Family, it is funded by EU LIFE+ Nature [LIFE13 NAT/UK/000209 – LIFE Shiants] and private donations. The eradication is being led by Wildlife Management International with the support of Engebrets and Sea Harris Ltd.
A particularly unusual plant called yellow bird’s nest has been found growing at RSPB Scotland’s Skinflats reserve, which sits on the edge of the River Forth. This is only the fourth time that it has been seen in Scotland since 2000 and all of the previous records were at sites near Glasgow.
Yellow bird’s nest is interesting because of the complex relationship it holds with its surroundings. The flower is pale yellow in colour because it lacks the green pigment chlorophyll, which is essential for photosynthesis - the process by which plants convert the sun’s rays into energy. Because yellow bird’s nest doesn’t have this pigment it needs to look elsewhere for energy. It does this by stealing nutrients from a certain type of fungi which is, in turn, gathering its own food through a mutual relationship with nearby trees – as fungi do.
We think this complicated relationship may well be one of the reasons yellow bird’s nest is so rare in Scotland – there are a lot of elements that need to be in place for it to thrive. However, it may be that a lack of the right type of habitat is likely to be another factor.
This particular plant was discovered in an area of scrubby woodland at Skinflats. The reserve is relatively small with its expanse of salt marsh and mud flats providing a rich winter feeding ground for wading birds like oystercatchers and curlews, especially in autumn and winter
Paul Walton is RSPB Scotland’s Head of Habitats and Species. He recently made a visit to the kittiwake colony at Sumburgh Head, Shetland, that he surveyed in the 1990s. In this blog he writes about this visit and what he discovered about the colony on his return trip. If you love seabirds as much as we do we could use your support right now. RSPB Scotland is currently asking supporters to sign a marine e-action calling for better protection of Scotland's seabirds. It is part of a public consultation on 10 potential new protected areas. If you would like to add your name and show your support for our seabirds you can do so by clicking here.
On a bleached cliff-top, sea-pinks tremble in the gusts and breezes. Fulmars cut the air with stiff wings, juddering and swaying against updrafts. Below them, kittiwakes wheel and holler, guillemots whirr in at speed, trafficking prey fish to the offspring, careering in to the breeding ledges, greeting and quarrelling, chicks begging and gulping and digesting. Gulls and skuas are patrolling, seeking the next predatory opportunity, and beneath it all a deep green Atlantic swell batters and caresses the rock face. This is pungent fertility, grace and menace on an oceanic stage.
I only have to sit here at this basement desk and imagine a seabird colony in June, and my pulse quickens. For most of the 1990s I worked for Glasgow University as a seabird researcher, based at Sumburgh Head at the southern tip of Shetland. Between April and September every day was spent on and around the cliffs, monitoring chick growth, ringing and radio-tracking adult seabirds, assessing breeding performance.
But for me, even more than the excitement of hands-on science, the most memorable activity was the hide watches. The research team would take turns to sit in small huts dug-in to the cliff-tops, weighed down with boulders. From these hidden viewpoints we watched and recorded the daily life of the colony. These watch rotas would go on for days at a time, and called for absolute concentration so that we gathered accurate data on presence and absence of breeding adults at the colony, the feeding frequency of the chicks, the timing of egg laying and chick hatching.
There is something spellbinding about spending long periods sitting quietly, unseen, and simply looking, witnessing wildlife first hand. It is less a theatrical drama unfolding, or voyeurism, more a close and intimate engagement with the reality of nature, and that is an immense privilege.
In some years there were low numbers of sandeels, the keystone prey fish species in Scotland’s marine ecosystem. Then, we would watch our study colony of 60 or so kittiwake nests reach extremes whereby an adult would depart on a foraging trip, heading out from the colony straight into the teeth of a North Sea gale, and not returning sometimes for fully 48 hours. Parent kittiwakes share the nest duties 50:50 and, during this time, that bird’s mate must remain at the nest constantly, unable to feed, guarding eggs and chicks from predators. But a small bird - and kittiwakes are astoundingly delicate in the hand - with a high metabolic rate will struggle with such long periods of forced starvation.
Seabirds are long-lived animals and most will breed several times during their lives. Some of these breeding attempts will fail quite naturally. These kittiwakes had, in effect, to make a decision: either stay on, enduring periods of starvation that, together with flying huge distances to find enough food for the young, might lead to long term physiological damage for the adult; or abandon this year’s breeding attempt and try again in future.
In the very poorest year for sandeels during our 1990s study, we watched as each kittiwake pair slowly, one after the next, abandoned their nest. The moment a chick was left alone, a gull or a skua, with hungry chicks themselves of course, would swoop in and take it. That year breeding success in the kittiwake colony was zero. But we returned to our hide the following spring to see the cliff occupied once more, with the same parent birds (the very same individuals that we had ringed, each with a unique colour combination) returning to breed successfully. We toasted them with cans of lager, and set about recording the year’s successes in our notebooks.
As the years of fieldwork proceeded, the unfolding life stories of these birds took on a sense of timelessness. The marine environment fluctuated, with big differences between the years, but I began to sense how seabird adaptations – not least their longevity and multiple breeding attempts in each adult lifespan – helped these incredible birds persist in, and as an integral part of, that marine ecosystem.
The Glasgow University research team’s colony photograph of the Sumburgh kittiwakes, 1993: each nest is marked with a red dot. Virtually all of these nests are now abandoned. c/o Prof Pat Monaghan.
It turns out I was complacent. I recently returned to Sumburgh Head at the height of the seabird breeding season. I was staggered, by what I saw. That sense of timelessness and continuity crumbled in seconds. The cliff-top kittiwake study hide that we had built back in 1990 was, to my amazement, still there – lichen encrusted and weathered, but still standing. The kittiwake colony that it looked onto, on the cliff opposite – the colony we had followed so closely and intimately for so many years - was silent. Of the 60 busy, screaming, displaying, fighting pairs, three remained, deep in the cliff cave – with no chicks visible. I could hardly believe my eyes. I left Sumburgh wounded.
This tragedy has played out across Shetland and Orkney, in other parts of the UK, beyond in the Nordic countries, and indeed across the world. Kittiwakes, arctic terns, arctic skuas, puffins – birds for which Scotland has global significance - have experienced poor food supply for such long extended runs of years that the longevity of individual adults is insufficient to maintain numbers, and huge population declines have now taken hold.
The cause is deep and fundamental shifts in the marine food-chain driven by human-induced climate change. Recent decades have seen the biomass of the zooplankton, on which the sandeels feed and depend, plummet by more than 70% in the NE Atlantic. Climate change is warming the sea surface and this is generating asynchrony in the timing of zooplankton breeding, and the timing of the annual phytoplankton bloom on which they graze. The system is out of seasonal synchrony and, to compound this, nutrient-poor warm water plankton species are beginning to replace the nutritious cold water species. Fewer sandeels is the result, with inevitable knock-on effects on the breeding success and survival of their predators - the seabirds.
The human impact on nature has, in our lifetimes, moved to a new and terrifying scale - and these climate change effects in the marine environment are for me the starkest illustration yet of how profound that impact has become.
But we can act to help. RSPB Scotland and our conservation partners lobbied hard and successfully for a Scottish Marine Act. We are pressing for the effective management of a network of protected areas at sea, where seabirds and other marine predators can feed. We are also working to build a programme that will restore as many seabird breeding islands as possible - making them free from the mammal predators, introduced by people, that decimate breeding seabirds.
If you would like to do something positive today to help protect Scotland's seabirds then we would urge you to sign our marine e-action. The Scottish Government has put forward 10 marine sites to be officially designated as protected areas for the seabirds that use them. A public consultation is open now, to get your views about whether they need to be protected. We have responded asking that they are all designated as soon as possible and you can support our call to action here. It's a great first step towards getting these birds the protection they need.