by Dave Goulson
The reason that arable weeds remain common in the machair is due to the low-intensity farming practices that still take place there. Farms in the region are called crofts, and are often tiny, a few acres of fenced fields close to the farmhouse, which is traditionally a low stone hut with enormously thick walls and often just one or two rooms inside, although most such buildings have now been replaced with more modern dwellings. The crofters usually share ownership and management of more extensive areas of machair and moorland, traditionally grazing the machair in winter and putting their sheep up on to the hills in summer. Patches of machair are occasionally planted with crops, small patches of potatoes, oats and rye, traditionally fertilised with seaweed carried up from the strand line on the beach, with these patches commonly being left fallow for a year or two after cropping. Because of their remoteness and the small scale of the farming, the use of artificial fertilisers and pesticides caught on more slowly out here, and remains much lower than on the mainland. Seen from above, the plain of the machair is chequered with small patches of crops interspersed with patches of fallow land of varying ages, set in a matrix of clover-rich pasture. It provides an increasingly rare example of how man’s activities can promote wildlife, creating a wonderful mosaic of habitats that collectively support a great diversity of life.
Looking at a distribution map for the great yellow bumblebee today, one could be excused for concluding that this is clearly a coastal species, for there are no populations more than about eight kilometres from the sea, most much less than that. One might even think it a species that specialises in living on the machair, for this is certainly where it is most common. However, a moment’s reflection reveals that this is clearly not true – old records suggest that the great yellow used to be found scattered across England; for example, there are records from Warwickshire, a county that is not known for its extensive coastline or its machair grasslands. In Europe, the great yellow can be found in southern Poland, more than 1,000 kilometres from the nearest coast. It is not that this species prefers the coast, it is more that the flowers on which it depends are now only found in sufficient abundance at coastal sites, at least in the north of the UK where this species seems to be most at home.
It is not really clear why the great yellow is so rare. Watching them in the Uists, it quickly becomes obvious that they do not have particularly unusual flower requirements. They have relatively long tongues for bumblebees, and so feed on deep flowers such as yellow rattle, kidney vetch, tufted vetch, red clovers and knapweeds, but they will also opportunistically visit a range of other flowers, including the domesticated roses I saw them on in gardens. Neither do they seem to be especially fussy about where they nest – although their nests are not found often, those few records we have (some of them thanks to a sniffer dog that we once trained for the purpose) suggest that they often use old rabbit burrows, something that is not in short supply in most of the UK. Of course, the flower-rich grasslands that the great yellow prefers are much less common than they used to be a hundred years ago, when the UK was awash with hay-meadows and chalk downland, but we do not yet have a convincing explanation as to why the great yellow has been hit harder than almost any other bumblebee species. One long-tongued bumblebee species, the garden bumblebee, remains fairly common all over the UK. According to the thousands of records we have amassed over the years, it feeds on a near-identical range of flowers to the great yellow. Clearly flower preferences alone do not explain why some species are more sensitive to habitat loss than others.
Sadly (for the wildlife, at least), crofting is changing. Most crofters are over sixty years old, and they are not being replaced, as their children tend to choose not to follow in their footsteps. Crofting is a hard life, for a traditional small croft cannot support a family – most crofters also have part-time jobs to supplement their income, and even then they will always live very modest lives. These tiny farms qualify for only small farming subsidies, while much larger sums are dished out to relatively wealthy farmers elsewhere in Europe. This is not a glamorous career choice. Children growing up today watch the television or surf the Internet, and realise that there is more to life than eking out a living on the edge of the world. They want pubs and clubs, shops, excitement: and who can blame them? So they leave, heading off to the bright lights of Glasgow or London, and slowly the crofts are falling into disuse. Abandonment of cropping leads to the loss of the arable weeds, and cessation of grazing by sheep in the winter leads to the machair vegetation becoming tall, dominated by coarse rushes, and developing a thick thatch of dead grass and other vegetation, so that floral diversity slowly declines.
While some crofts have been abandoned, others have been acquired and merged into larger operations, often dependent primarily on sheep ranching. The tradition of moving sheep to the hills in summer is often no longer practised as it is time consuming and more difficult to keep an eye on the animals, so many of the larger ranching operations maintain high densities of sheep on the machair right through the summer. This is pretty hopeless for bees as the sheep keep the sward grazed down close to the ground. Almost nothing can flower since sheep love to consume buds, so there is no food for pollinating insects.
These shifts in farming practices have had similar negative impacts on another iconic Hebridean creature, the corncrake, a species with a history of declines in the UK that closely parallels that of the great yellow. This odd bird, related to the moorhen, prefers to nest in long grass: cereal fields, hay-fields and ungrazed summer machair. It is not an especially remarkable creature to look at: bantam-sized, and beautifully camouflaged in fawns and russet with darker flecks. It used to be common across Britain, but declined swiftly as new crop varieties and availability of fertilisers enabled crops to be harvested earlier. Just as with the great bustard, which also likes to nest in open fields, there was no longer time for the chicks to fledge before the crop was harvested. Thousands of nests were simply mown over, the eggs and chicks destroyed. The switch from hay, which is cut in summer, to silage,fn3 which can be cut several times through spring and summer, was particularly devastating. In Northern Ireland, a campaign to encourage farmers to produce silage instead of hay, and to encourage them to keep more sheep, resulted in an 80 per cent drop in the corncrake population in just three years between 1988 and 1991. The Hebrides is now the last UK stronghold for this species, though only a few hundred remain. It is a shy bird, rarely leaving the long grass, so we did not see one on that trip, but I have been lucky enough to hear them and briefly see them since then on a spring visit to the Isle of Oronsay in the Inner Hebrides, an island that is entirely managed by the Royal Society for the Protection of Birds to encourage rare birds such as chough and corncrakes. In the breeding season in mid spring, just after the corncrakes have arrived back from Africa on migration, the males attempt to attract females with their call – a dry rattle that sounds more like the work of a giant grasshopper than that of a bird. Unlike the flamboyant great bustard, the males are shy, secretive creatures, calling from deep cover and mostly at night. On Oronsay their night-time calls were so incessant that several stiff measures of Laphroaig whisky were needed before I could get off to sleep.
There is no point in blaming anyone for the changes that led to the demise of the corncrake and the great yellow bumblebee. The world has moved on, and inevitably traditional ways of life are lost as new ones develop. The challenge for society is working out what to do. We could heavily subsidise traditional practices, essentially paying crofters to carry on doing what they used to do in the hope that this props up rural communities and helps to preserve the wildlife associated with crofting. This would be expensive for taxpayers, and runs the risk of creating a Disneyesque parody of rural life. On the other hand, if we allow crofting to disappear then some of the unique wildlife of the machair is likely to disappear. The RSPB now manage some big chunks of the Hebrides, including a sizeable area of machair on North Uist, and with their considerable resources, and working closely with locals,
hopefully they can conserve some of the character of the land and the biodiversity it supports.
For the moment at least, great yellows and moss carders do seem to be holding their own in the Uists. However, there are other threats looming in their future. These populations are now highly isolated; where once there were populations on the Inner Hebrides and the mainland, sources of immigrants to bring in ‘new blood’ – genes from outside – now there are none. There is a distinct danger that these populations will slowly become inbred over time, losing vital genetic diversity, and that they will eventually fizzle out as a result, regardless of whether the habitat survives or not. This was exactly what Ben was studying, by taking DNA samples from each bumblebee species to be found on the different Hebridean islands, so that we could measure how much genetic diversity remains, and estimate how often bees move between the different islands.
We were particularly keen to get genetic samples from the most isolated bumblebee populations of all, on the Monach Isles. From North Uist the Monachs can be seen in the distance as a grey smudge on the western horizon. A cluster of low-lying islands, they lie about ten kilometres further west into the North Atlantic than the main chain of the Outer Hebrides. They are not currently inhabited, and hence there is no regular transport, so we were unclear as to how we might get out there.
As we travelled the Uists and Benbecula, collecting genetic samples and information on the basic ecology of the different bee species, we asked the few folk that we encountered whether they knew of a way out to the Monachs. For several days we drew a blank, though the conversations were worth it to hear the lovely, gentle accent of the locals – to my ear a blend of Highland Scottish and southern Irish. Many of these people were more comfortable with their native Gaelic than speaking English. Eventually we chanced to ask in the hardware store on Benbecula. The store’s owner, a tall, weatherbeaten character, introduced himself as Ronald McDonald, forcing me to splutter as I choked back laughter – I guess perhaps he was used to the reaction. It would have been less funny had he not had a large red nose. Ronald happened to know a Donald MacDonald, no relation, who kept a flock of sheep on the Monachs, and went out to check on them periodically. He very kindly offered to look up Donald’s number in the telephone directory. This took longer than you might think, for although the local Benbecula telephone directory is little more than a pamphlet compared to the sturdy doorstop that most of us are used to on the mainland, the MacDonald section covered several pages, and there were dozens of entries for ‘MacDonald, D’. Eventually we found the correct number, but could then get no reply. It took a couple of days of repeated calls before we eventually got an answer, only for this to turn out to be a dead end; Donald had recently been out to tend his flock and was not planning to go back in the near future. We’d missed our chance.
We were running out of time, with only two days before my return flight, when, by chance, a casual conversation with some birdwatchers revealed that they had managed to charter a boat to go out to the Monachs the very next day. As luck would have it, there was room on board for two more, and they were very happy to split the fee. We arrived at our rendezvous point on a remote beach a little early the following morning, just after dawn, and as we waited we were lucky enough to see an otter come in from the sea and lollop up the beach not fifty metres away. It didn’t seem to notice us, and stopped to wash itself for a moment before disappearing into the tussocky dunes. Shortly afterwards the birders arrived, chatting excitedly and laden with a plethora of binoculars and camera bags, and then our lift hove into view around the headland to the north, a large rubber inflatable with two huge Yamaha outboard motors, piloted by a capable-looking guy named Craig sensibly kitted out in a thick black rubber dry suit. We waded in to the chilly waters to climb aboard, and soon we were skimming across the choppy sea towards the distant Monachs. It felt like a fairground ride as we scudded at speed over the peaks of the waves, shivering in our damp clothes, eyes squinting against the stinging spray. Within twenty minutes we entered the smoother water in the lee of the islands and our pilot powered down the engines.
There is something magical about exploring an uninhabited island that brings out the inner child in all of us. We were eager to see what we could find, and we scattered in different directions, Ben and I with our butterfly nets at the ready, the others brandishing their binoculars and long-lensed cameras. It was a beautiful day, and I quickly warmed up as I headed to the highest spot I could see, an enormous system of dunes that rose perhaps forty metres above the beach. From the top, I could see across the entire island chain. The Monachs really consist of three separate islands which together stretch over about four kilometres, joined at low tide by bars of white shell-sand, plus numerous smaller rocky outcrops protruding from the surrounding sea. The islands once supported a small community of perhaps one hundred people, fishermen and crofters, all of them somehow eking out a living here, surviving on what they could grow in the thin soil or catch from the sea.fn4 There was even a tiny school and a nunnery. Rectangles of crumbling stone walls are all that remain of their houses and livestock pens – the last people left in 1942. Until the fifteenth century, it is said that it was possible to walk from the Monachs to North Uist along sandbars at low tide, though it must have been a perilous journey rushing across the ten kilometres before the sea returned. Legend has it that this sandbar was swept away by a storm surge. There is no protected harbour on the islands, so from then on these folk must have been cut off from outside contact whenever the seas were rough, which out here is likely to have been much of the time.
Today there are no people, but the islands are infested with sheep. From the top of the dunes I could see hundreds of them, heads down, munching away. There seemed to be far more than such tiny islands could support. The flatter areas of the islands, inland from the dunes, are classified as machair, but this was a pretty poor sort of machair compared to that which we had seen on the Uists. It was grazed so intensively that the vegetation rose perhaps half a centimetre above the soil. The plants were miniaturised: bonsais, their leaves tiny, their stems prostrate against the ground. Normally, plants compete with one another, growing upwards to reach the light and shade their neighbours. Here, the plants pressed themselves against the ground, vying to get away from the endlessly nibbling lips of the sheep. There were quite a variety of plants; from their minuscule leaves I could identify red and white clovers, vetches and trefoils, but none were in flower. Any flower bud would be eaten long before it could open. In places, the vegetation had been stripped away completely, allowing the wind to blow out the soil, forming hollowed out bunkers.
I have a friend who disdainfully refers to sheep as woolly maggots. Environmentalist and writer George Monbiot has written at length about the adverse impacts that overgrazing by sheep (and deer) has had on the uplands of Britain, destroying the vegetation, preventing young trees from getting established, turning vast areas into monotonous grassy swards with almost no wildlife remaining, and compacting the soil surface so that rainwater flashes off the hills to cause floods many miles downstream. He argues eloquently that such farming employs only tiny numbers of people, contributes very little to the economy, and yet is heavily supported by subsidies of taxpayers’ money. Why should we pay to support such a destructive practice? As I explored the Monachs, I couldn’t help but think that he may have a point. These islands are classified as ‘Sites of Special Scientific Interest’ and are also a National Nature Reserve, and hence ought to be protected areas, managed for wildlife, where flowers, bees and all the other creatures associated with the machair could thrive in peace. This was what I had imagined they would be like. Instead, they were a barren, insect-free bowling green. It was disappointing, to say the least.
