Risso’s dolphins in the Sound of Eriskay
On Thursday, 11th August three dolphins were observed swimming around on the east side of Eriskay causeway, near the bridge. One very much smaller than the others stayed close beside one of them, so almost certainly a mother and calf.
There was some discussion initially about the species; only brief views of parts of the head and back were visible when they took breaths. Initial suggestions were Atlantic white-sided dolphin; or possibly Bottlenose dolphin; but eventually close scrutiny of some good photographs and video sequences led to the conclusion that they were Risso’s dolphins (Grampus griseus). Some photographs showed pale parallel lines on the sides of the calf, the remains of ‘foetal folds’ resulting from it having been curled up inside the mother; evidence that it was probably no more than a few weeks old. Apparently Risso’s dolphins have been seen on a number of occasions on the east side of Uist recently.
There was concern that they might strand as although there is a deep channel from west to east, at low tide much of the sound is very shallow and large areas dry out, especially at spring tides as we had just then. The two larger ones did indeed become grounded in shallow water after midday on Friday, but by 2pm the rising tide refloated them to swim freely. There were no further reports of their stranding.
British Marine Divers Life Rescue (BMDLR) were alerted to the situation, and although they have no trained volunteers in Uist, could have helped if necessary. They passed the news on to the Scottish Marine Animal Strandings Scheme (SMASS), which also kept in touch with local volunteers.
The three animals stayed on the east side of the causeway, showing no inclination to pass through to the west, though at times they were close to the bridge. They also went over towards Sgeir an Fhèidh, and latterly further away towards the open waters of the Minch.
Generally’ they seemed to be swimming about quite calmly, showing no signs of distress, with only the upper parts of the head and back visible as they rose to breathe. The single animal was observed ‘spy hopping’ occasionally and also vigorously tail slapping.
By the morning of Wednesday 17th our visitors had departed.
News had got around quickly and over their few days’ stay, the dolphins attracted a lot of attention from residents and passing summer visitors, who gathered on the causeway to watch them, hoping they would be all right.
Many people contributed to this note, not least Chris Brooks, Peter Keiller and Donald Iain Campbell, who had very helpful observations, photographs and video sequences, Mariel ten Doeschate of SMASS for discussion of the species and age of the calf, Dan Jarvis of BMDLR, Mary Margaret Morrison, who saw them from her bus and other residents for keeping in touch and reporting their observations, and David Steele for his observations in the Minch.
Photos by Peter Keiller and Carla Brooks
Uist Community Tree Nursery plans for home grown saplings
Stòras Uibhist, Tagsa Uibhist and the Woodland Trust are working together to create the Uist Community Tree Nursery. A trial project to grow 1,000 native trees is now underway with the expectation that the young trees will be planted out next Spring.
The ‘mini-plug’ trees were hand delivered by tree guru, Craig Shearer, whose work for the Woodland Trust supports smaller nurseries and seed-collection ‘hubs’ throughout Scotland. Craig spent a July afternoon at Tagsa Uibhist, imparting his expert knowledge and devising a care plan to nurture the plants. The young trees will be looked after and closely monitored by Tagsa Uibhist staff and volunteers, with the main concern being keeping them safe from the hungry East Camp rabbits.
Viv Halcrow, Croft Woodlands Adviser for Uist and Barra said: “It is inspiring to see such high interest in establishing small areas of native trees on crofts and in the community. These will fit in with other crofting activity, benefit wildlife, add a missing dimension to the landscape, and maybe most importantly, provide shelter for stock, housing, and people!”
The opportunity for the new nursery project came about through Viv’s project work, which highlighted that the considerable demand for trees in Uist was being hampered by significant challenges with the supply chain: “Through the six years of the Croft Woodland Project, we have had to bring practically all the planting stock from the mainland. I’ve always felt that an island nursery would make a lot of sense, as we can use seed from local trees, reduce transport costs and delays, and ultimately, hopefully, the nursery could become a small business opportunity”.
Once the trial has completed, the hope is to scale up to producing 10,000 trees per year with the majority being supplied to the Woodland Trust for local projects and the remainder being made available for people to purchase directly from Tagsa Uibhist.
Olli MacLennan, Community Gardens Manager at Tagsa Uibhist said: “Trialling a Uist Tree Nursery within Tagsa Community Gardens’ existing infrastructure and utilising the current skeleton staff and site grounds is a logical approach to setup for us, allowing us to monitor and record required maintenance needs, time, and resources to estimate future commitments for scaling up to 10,000 seedlings/saplings. It’s an exciting step for us in Community Gardens, with a team made up of dedicated growers, and a real privilege to work in collaboration with Stòras Uibhist and the Woodland Trust.”
Tagsa Uibhist Chief Executive Chris MacLullich said: “In Tagsa we see this as a fantastic opportunity for our volunteers and Community Gardens team to work together on a meaningful project that will improve the environment in which we live in Uist. It’s a great collaboration and will be part of the Uist response to the climate emergency. These trees will sequester carbon over their lifetime and contribute to mitigating global heating. We hope to scale up after a successful first year”.
Stòras Uibhist has been closely involved with setting up the trial and will be planting the 1,000 trees out across the estate in Spring 2023. Darren Taylor, Chief Executive: “We are delighted to be collaborating with Tagsa Uibhist and the Woodland Trust on this brilliant project that will bring so much community benefit.”
Late summer butterflies
Red Admiral, Painted Lady, Small Tortoiseshell and Peacock (known collectively as vanessids) must be amongst our most familiar butterflies and can regularly be seen taking nectar from late flowering summer plants such as marsh thistle, devil’s-bit scabious and buddleja
All four species occur in the Outer Hebrides. Red Admiral and Small Tortoiseshell are the ones you are most likely to see. Painted Lady is a long distant migrant than can occur in their thousands in good years but is hardly recorded at all in other years. The Peacock is less predictable but perhaps under recorded here and is maybe a recent colonist or re-colonist. For all of them, the nectar they consume in late summer and early autumn is vitally important in helping them survive the winter. It’s all about building reserves of body fat.
Two of our species over-winter here as adults and they need those reserves to survive their hibernation during the cold months. As temperatures drop in autumn Small Tortoiseshell and Peacock butterflies seek out sheltered hibernation sites in woodpiles, sheds and other outbuildings and even inside our houses. The reserves laid down in late summer keep them ticking over until temperatures start to rise again in spring.
For the other two species, Red Admiral and Painted Lady, the reserves are for more immediate use. Both species are long distance migrants and they need energy for their return migrations. The earliest sightings of these species are from late march and early April. These individuals may have been carried here by strong winds directly from overwintering sites in North Africa. Later sightings in June and July are probably from intermediate generations that bred somewhere in Europe. The arrival, here, of most of these butterflies in spring is an example of a “multi-generational long distance migration”. They may have had one, two or three generations en route before they get to us.
What happens to those Red Admiral and Painted Lady butterflies we see in August? It used to be thought that many of these butterflies, seen in the UK in late summer, simply died. For them, it was a one-way trip. We now know differently. Entomologists using vertical looking radar have been able to look at the movements of insects to and from the UK. This type of radar is very sensitive and has been used to look at movement of plant pests such as aphids as well as larger insects. Radar studies on the movement of butterflies such as the Painted Lady and Red Admiral have given us the real picture.
In 2009, one of the biggest Painted Lady migrations of recent years, it is estimated that 11 million of them arrived in the UK. Some of these made their way to the Outer Hebrides. Over the UK as a whole they had a successful breeding year and an estimated 22million left the UK in autumn. Flying at heights between 200m and 1200m they headed for North Africa. Winds at these heights are 4-8 times faster than at ground level and butterflies can reach speeds of 100kph (approx. 60mph) and accomplish flights of 1000km with ease. If you are lucky enough to spot a Painted Lady nectaring on a marsh thistle in late summer, just think, it’s next stop for food might be in North Africa.