Research from the University of Aberdeen is investigating how honeybees and rare Hebridean bumblebees share - and compete for - resources in the islands' unique flower-rich landscapes
The three-year Hebri-bees project seeks to provide answers to the question of whether managed honeybees are negatively affecting wild bumblebee populations, including the iconic great yellow bumble bee.
Led by ecologist Dr Johanna Yourstone, the study will focus on the Hebrides’ internationally important machair habitats – flower-rich coastal grasslands – to investigate whether honeybees compete with rare bumblebees for food, when any overlap in foraging occurs during the season, and whether disease transmission between managed and wild bees may play a role in bumblebee decline.
While many previous studies have examined bee competition in agricultural landscapes, Dr Yourstone says these tend to be homogeneous and are very different to the abundance of flower species found in the machair.
“The Hebrides are an ideal study system for rare bumblebees,” said Dr Yourstone. “In many other places, these species survive only in tiny numbers, making meaningful research extremely difficult. Here, the islands still hold strong populations and extraordinary flower-rich habitats, giving us a rare opportunity to understand how these bees live, forage and respond to environmental pressures.”
The research will include the great yellow bumblebee which, once widespread across the UK, is now largely confined to northern Scotland’s coasts and islands, with the Inner and Outer Hebrides acting as its main strongholds and the threatened moss carder bee, which earlier University surveys identified as the most common bumblebee in the machair.
“The great yellow bumblebee is more than just a rare insect – it’s a beloved symbol of the Hebrides,” Dr Yourstone added.
“People care deeply about these bees, and understandably there are questions about whether increasing beekeeping could affect them.
“It is a particularly delicate question in this area as the nowadays rare, pristine lineage of honeybees - the black bees - are kept on many of the islands.”
“What we need now is robust evidence, so that future decisions are guided by science rather than assumption.”
The Hebri-bees team will combine field observations with cutting-edge pollen analysis, using microscopy and AI-assisted techniques to identify the flowers visited by different bee species across the season.
Dr Yourstone said: “We’ll be following the pollen trail to understand exactly where Hebridean bees are foraging.
“It may be the case that we see honeybees flying across the machair, but pollen analysis could show they were actually collecting most of their food from heather elsewhere. Looking at the pollen gives us a much clearer picture of what’s really happening in the landscape.”
The field study spans across the Hebrides, from Islay to Lewis, as well as parts of Scotland’s north-west coast. Researchers will work closely with local organisations such as the RSPB, volunteers and beekeepers throughout the project.
Dr Yourstone stresses that the aim is not to pit honeybees against bumblebees, but to understand how both can coexist sustainably in sensitive island ecosystems.
“Honeybees and bumblebees are both important pollinators. Our goal is to understand where interactions occur, whether they matter for rare species, and how we can support healthy pollinator communities across these islands.”
By combining ecology, behavioural studies and molecular analysis, the Hebri-bees project, which received support through a bursary from Species on the Edge, aims to provide one of the most comprehensive pictures yet of how managed and wild bees interact in a natural island environment.
Pròiseact Hebri-bees ri àm teachdail phoileanadairean tearc nan eilean a rannsachadh
Tha rannsachadh le Oilthigh Obar Dheathain a’ dèanamh sgrùdadh air mar a tha seilleanan-meala agus seilleanan-mòra tearc Innse Gall a’ co-roinn – agus a’ farpais – airson ghoireasan ann an cruthan-tìre mòr-fhlùranach air leth nan eilean.
Tha pròiseact trì-bliadhna seilleanan Innse Gall a’ strì ri freagairtean a lorg don cheist mu dheidhinn a bheil seilleanan-meala a’ toirt buaidh àicheil air àireamhan sheilleanan-mòra fiadhaich, agus nam measg tha an seillean mòr suaicheanta buidhe.
Air a stiùireadh leis an eag-eòlaiche, an Dr Johanna Yourstone, bidh an sgrùdadh a’ cuimseachadh air àrainnean machrach Innse Gall a tha cliùiteach gu h-eadar-nàiseanta – raointean-feòir fhlùranach shaidhbhir a’ chosta – gus sgrùdadh a dhèanamh air a bheil no nach eil seilleanan-meala a’ farpais ri seilleanan-mòra airson biadh, nuair a bhios tar-iadhadh sam bith ann an rùrach a’ gabhail àite tron t-seusan, agus am faod àite a bhith aig sgaoileadh galair eadar seilleanan stiùirichte agus seilleanan fiadhaich ann an crìonadh nan seillean mòra.
Ged a tha mòran rannsachaidhean eile air farpais sheilleanan ann an cruthan-tìre àiteachais a sgrùdadh, tha an Dr Yourstone ag ràdh gu bheil iad sin buailteach a bhith aon-ghnèitheach agus gu bheil iad glè eadar-dhealaichte bho lìonmhorachd ghnèithean nam flùraichean a lorgar air a’ mhachair.
“Tha eileanan Innse Gall nan siostam sgrùdaidh foirfe airson seilleanan-mòra tearc,” thuirt an Dr Yourstone. “Ann am mòran àiteachan eile, chan eil na gnèithean sin a’ soirbheachadh ach ann an àireamhan fìor bheag, a’ dèanamh rannsachadh brìoghmhor air leth doirbh. An seo, tha na h-eileanan fhathast a’ gleidheadh àireamhan làidir agus àrainnean flùranach saidhbhir a tha iongantach, a’ toirt dhuinn cothrom ainneamh air tuigsinn mar a tha na seilleanan sin beò, a’ rùrach, agus a’ dèiligeadh ri dùbhlain àrainneachdail.”
Bidh an rannsachadh a’ gabhail a-steach sgrùdadh air an t-seillean-mhòr bhuidhe, a bha aig aon àm ri fhaotainn fada is farsaing air feadh na RA, ach a tha a-nis sa mhòr-chuid cuibhrichte gu costa a tuath agus eileanan na h-Alba, le Innse Gall a-staigh agus a-muigh mar am prìomh àite-dìon dhaibh agus do sheilleanan-càrdair a’ chòinnich, a chomharraich suirbhidhean Oilthighe na bu thràithe mar an seillean-mòr as cumanta air a’ mhachair.
“Is e barrachd na dìreach biastag a tha tearc a th’ anns an an t-seillean mhòr bhuidhe – is e samhla gràdhaichte de Innse Gall a th’ ann,” thuirt an Dr Yourstone.
“Tha cùram domhainn aig daoine do na seilleanan sin, agus tha e furasta a thuigsinn gu bheil ceistean mu dheidhinn am faodadh meudachadh ann am beachaireachd buaidh a thoirt orra.
“Is e ceist gu h-àraid cugallach a tha seo san sgìre seo oir san latha an-diugh tha an ginealach neo-thruaillte de sheilleanan-meala – na seilleanan dubha – air an cumail air mòran de na h-eileanan.”
“’S ann a tha feum againn a-nis air fianais làidir, gus am bi co-dhùnaidhean san àm ri teachd air an stiùireadh le saidheans seach le ro-bheachd.”
Bidh sgioba sheilleanan Innse Gall a’ cothlamadh fiosrachadh bhon bhlàr a-muigh le anailis ùr-ghnàthach air poilean, a’ cleachdadh micreascopachd agus altan-obrach le cuideachadh bho AI, gus na flùraichean a chomharrachadh air am bi na diofar ghnèithean sheilleanan a’ tadhal tron t-seusan.
Thuirt an Dr Yourstone: “Bidh sinn a’ leantainn slighe a’ phoilein gus tuigse mhionaideach fhaotainn air far a bheil seilleanan Innse Gall a’ rùrach.
“Dh’fhaodadh e a bhith gum faic sinn seilleanan-meala a’ sgiathadh air feadh na machrach, ach dh’fhaodadh anailis poilein a thaisbeanadh gun robh iad ann an da-riribh a’ trusadh na mòr-chuid de am biadh bho fhraoch ann an àiteachan eile. Tha sgrùdadh air a’ phoilean a’ toirt dealbh mòran nas soilleire dhuinn mu dheidhinn na tha a’ tachairt ann an da-rìribh sa chruth-tìre.”
Tha an sgrùdadh làraichean air a sgaoileadh air feadh Innse Gall bho Eilean Ìle gu Eilean Leòdhais, a thuilleadh air pàirtean de chosta an iar-thuath na h-Alba. Bidh rannsaichearan ag obair gu dlùth le buidhnean ionadail leithid an RSPB, saor-thoilich agus beachairean, gu deireadh a’ phròiseict.
Tha an Dr Yourstone a’ daingneachadh nach e an t-amas seilleanan-meala a chur an aghaidh seilleanan-mòra, ach tuigse fhaotainn air mar a ghabhas an dà ghnè a bhith beò còmhla gu seasmhach ann an eag-shiostaman cugallach nan eilean.
“Tha seilleanan-meala agus seilleanan-mòra le chèile cudromach mar phoileanadairean. Is e an ceann-uidhe againne, tuigsinn far a bheil eadar-obrachadh a’ gabhail àite, a bheil iad cudromach do ghnèithean tearc, agus mar as urrainn dhuinn taic a chur ri coimhearsnachdan phoileanadairean fallain air feadh nan eilean seo.”
Le bhith a’ co-mheasgachadh eag-eòlas, sgrùdaidhean mhodhan-giùlain agus anailis moileciuileach, tha pròiseact Hebri-bees, a fhuair taic tro bhursaraidh bho Ghnèithean air an Oir (Species on the Edge), ag amas air aon de na dealbhan as uile-chuimsich fhathast a thoirt seachad de mar a tha seilleanan stiùirichte agus seilleanan fiadhaich ag eadar-obrachadh ann an àrainneachd eileanach nàdarra.