All smiles on the sunshine isle

Our latest guest blog comes from Tiree, ‘the sunshine island’. Low-lying and fertile, it boasts excellent areas of machair. Although often windy – there was once a wind of 116mph recorded here – it is a fabulous place to enjoy nature, and as Janet Bowler’s blog reveals there has been an exciting finale to the great yellow bumblebee community project on the Isle of Tiree!

By Janet Bowler

It has been a while since my last guest blog about Tiree’s Great Yellow Bumblebee Project, the final one of which should really have been produced in late 2020. But as with so many other efforts, the covid-19 pandemic disrupted some elements of the project, notably by restricting the number of bee surveyors who could visit the island and by delaying the publication of the children’s storybook. Looking on the bright side, however, these delays have enabled inclusion of an extra year’s worth of exciting observations.

Great Yellow Bumblebee (C) and courtesy Andy Robinson

Population Surveys

Although we didn’t have the assistance of additional surveyors in 2021 (or 2020), a handful of locals conducted a few surveys at key sites in August, the busiest month for GYBB colonies when workers, queens, daughter queens and males are all active. We were astounded with our findings: we each counted many more individuals per hour than in any previous year. Excited by this result, we plotted the August data from a few key sites (Figure 1). The data probably wouldn’t stand up to rigorous statistical scrutiny, but they do give an overall impression of GYBB activity over the duration of the project, and an indication of the most productive sites. 

Figure 1. Mean counts of great yellow bumblebees per 1hr survey of flowering machair at Aird, An Fhaodhail dunes (An F), South Hough (S Ho), Barrapol-Sandaig (Barr), and Abhainn Bhi (A Bhi), in the Augusts of 2017-2021. NB. No great yellow bumblebees were seen during the August 2018 survey at An F; surveys at A Bhi did not begin until 2019.

It could be argued that the increase in counts is due to increasing spotting skills amongst the surveyors, but as trends varied between some sites, and as all observers recorded significantly more GYBBs in August 2021, it seems more likely to be a true reflection of numbers. In any case, we can attribute the changes between years to weather conditions.

Growth of the bees’ forage plants was hindered by a prolonged summer drought across all sites in 2018. 2019 was mostly cold and wet but warmed up in late summer. The weather in 2020 created a roller-coaster ride for flowers and bees, but finally settled to warm, wet and sunny conditions resulting in simultaneous blooming of all the GYBBs favoured forage flowers, finally enabling successful breeding and a larger number of daughter queens to stock up for, and survive, winter hibernation.

Between April and June in 2021 was cold and no queens emerged from hibernation until warmer weather in late June, when larger numbers of queens than normal were recorded. Summer 2021 continued warm and windless, with occasional rain relieving the drought. This enabled copious machair flowers to support higher breeding rates for the GYBB colonies and, therefore, higher counts. Hopefully, this means that even more daughter queens will emerge from hibernation in Spring 2022.

Great Yellow Bumblebee (C) and courtesy of John Bowler

The above summary demonstrates the impact that the vagaries of the Spring-Summer weather can have on the GYBB’s success, and why, therefore, the species requires such large areas of diverse key forage flowers to ensure that, regardless of the weather, there are always resources available to keep the species going.

A Nest at Caoles

Against all the odds, two eagle-eyed visitors discovered a GYBB nest as they were cycling along the road to Caoles, at the east end of the island. Knowing that this was an important species (through this project), they stayed a while to watch and saw several bees disappear into the same patch of vegetation in the roadside bank. This was an important find. Not only was it just the third GYBB nest found during the entire five years of the project, but it was also close to an area of machair that GYBBs seemed to have disappeared from, raising our hopes that the population in that area could thrive again.

Great yellow bumblebee at nest site (C) and courtesy Jo Kennedy

Sensory garden success

Most of the ‘mini-machairs’ we sowed throughout the island in 2018 bloomed each year providing nectar and pollen for nesting bumblebees. One in particular was sensational – in the back garden at Tigh a’ Rudha Care Home.

It was a late addition, only being planted in 2019 as part of their Sensory Garden project, but it may be one of the most successful. In 2021, it bloomed spectacularly, delighting the residents with a yellow carpet of kidney vetch, bird’s-foot trefoil and autumn hawkbit, along with scatterings of red and white clovers, and tufted vetch, all favoured by great yellow bumblebees.

Children’s storybook

With much celebrating, the story about Betty – a great yellow bumblebee, created by Tiree Primary School children, was finally published in November 2021. Beataidh Banrigh – Super Bee is a warm and funny tale of friendship and wildlife conservation. It includes a fun plot, great characters and some zingy dialogue, and is told in both Gaelic and English. The children’s drawings, transformed into stunning illustrations by local artist Rou Worsley, are sumptuous in print. There is a page of useful and fascinating Bee Facts (some of which are needed to explain some of the strange behaviours of the characters!), and Forewords by Gill Perkins – CEO of the Bumblebee Conservation Trust, and Roddy MacLean – Gaelic broadcaster, writer and naturalist. What a high note to end Tiree’s Great Yellow Bumblebee Project on!

Further information:

Please email gybb@friendsoftiree.org.uk if you would like to purchase a copy of their book.

Northern star

They are busy folk at the Bumblebee Conservation Trust. Their mission may sound deceptively simple –  to increase the number and distribution of bumblebees – but they are astute enough to know that  you need many tools and heaps of energy to deliver such a critical ambition.

Their partnership with Scottish and Southern Energy Networks in the northern reaches of Scotland is a point in case. When the energy company looked, in 2017, to improve the area around their Thurso South substation for wildlife they sensibly sought out the Bumblebee Conservation Trust. The result was a highly productive partnership which resulted in a sizeable and well-thought out meadow.

That meadow was one step along the route to helping bumblebees in the north of Scotland. It was a well-designed project. A tailored pollinator seed mix, in harmony with the local conditions, was put to good use and surveys in 2018 and 2019 confirmed that insects were quickly using the site. In 2020 came the great news that the Great Yellow bumblebee had been spotted using the site.

The first Great Yellow bumblebee recorded at Thurso south substation meadow, August 2020.
Image (C) Katy Malone, BBCT.

The Great Yellow bumblebee was once widespread throughout the United Kingdom, but is now only found in a handful of areas, all of them here in Scotland –  Caithness, north-west Sutherland, the Hebrides and Orkney.  It is one of our rarest bumblebees, needing extensive meadows and particular types of habitats, such as machair, to survive from year-to-year. 

Twelve months on from that individual 2020 sighting the regular visits of a local volunteer established conclusively good numbers of Great Yellows using the site. And there was yet more good news when the Bumblebee Conservation Trust staff visiting in August 2021, during a research trip, were rewarded with a view of more than one queen bumblebees making the most of the Thurso resource. It’s not a quantum leap from there to surmise that the species is probably nesting on the site.

The success in Thurso helps illustrate progress and makes it easier to engage with the general public and landowners in a bid to inform future conservation of this species.

The Bumblebee Conservation Trust provides tailored advice to farms and landholdings to support beneficial management of sites for Great Yellow bumblebee through the Saving the Great Yellow Bumblebee project which as been running since 2019. New projects are always in the pipeline to carry forward this work and expand it even further. They provide follow-up support to farmers, landowners and agents across high priority Great Yellow areas and, where appropriate, advice on management options funded by SRDP-AECS (Scottish Rural Development Programme, Agri-Environment Climate Scheme). This advice is highly tailored to each site, ranging from suggesting suitable voluntary measures to adopt, through to helping with written letters of endorsement.

One element has been to employ survey consultants to gather data on forage and conduct bee surveys along the north coast of Sutherland, and the Outer Hebrides, in June through to early September. The intention is that these reports will highlight suitable areas to target more intensive surveys for Great Yellow bumblebees in the areas, record the quality of forage across the landscape, and suggests where a change in management might help encourage better habitats for this rare bumblebee. Another strand is looking at the genetic variability in Great Yellow populations to find whether genetic relatedness is increasing – this would affect the long term viability of these remote populations and help the Bumblebee Conservation Trust work out new approaches to conservation.

Conservation Officer (Scotland) Katy Malone is delighted to see these different threads coming together in a coherent drive to address the challenges facing the Great Yellow bumblebee. “We’ve made great steps forward in helping this iconic species thrive in new areas, but there is still so much work to do. Only with the help of our supporters, members and volunteers, and in partnership with business and conservation organisations, can we sustain this effort and see bumblebees thriving again across our landscapes. We need to deliver across entire landscapes from the Outer Hebrides right up to Orkney. I’m really excited to be a part of the development of new projects which will help us establish even more sustainable solutions.”

Trust staff finding Great yellow bumblebees at SSE Thurso south substation in 2021 during a research trip. Image (C) Katy Malone, BBCT.

Founded in 2006 and with almost 8,000 members, the Bumblebee Conservation Trust has a level of specialist knowledge, active nationwide groups and targeted projects that makes them a key partner in successfully delivering the Pollinator Strategy for Scotland. 

They work on a range of projects simultaneously, ranging from research and monitoring, through public engagement and information services, to leading effective campaigns. If you want to find out more then settle down in front of their website. It’s a fantastic resource to not only gain in insight into their projects, but find all sorts of practical and easy to follow advice on how to help bumblebees. Their ‘Bee Kind’ section is just one example featuring planting recommendations to enable us all to do our bit to help bumblebees and other pollinators.  

There is no doubting the Bumblebee Conservation Trust are busy, but equally there is no doubting their relentless focus in the battle to tackle the many challenges facing our native bumblebees. What’s going on in the north of Scotland is just one fine example.

Find out more:

The Bumblebee Conservation Trust website

Bumblebee Conservation Trust 2021 cash appeal

Bumblebee Conservation Trust gift membership