Shetland shines

One of the first naturalists to capture my imagination was Bobby Tulloch of Shetland. His tales of otters and snowy owls captivated me, and brought a touch of the northern isles and ‘simmer dim’ into my New Town home in East Kilbride. Tulloch was, to borrow a good old Scottish phrase, a ‘Lad o’ Pairts’, an all-rounder, and his photographs of flowers and ferns suggests he probably had a keen eye for the less obvious and smaller species like pollinators.

A road verge managed for visibility and wildlife. Image courtesy of http://www.austintaylorphotography.com

Few of the actions that help pollinators embrace glitz or glamour. Often the actions that deliver most are cheap and easy, requiring minimal investment. Indeed, in many instances it is simply to manage things differently, to ease back a little, that makes a telling difference. 

Shetland Islands Council has taken a leaf from that book and introduced a few measures which give nature a helping hand.  For example, they have amended their roadside verge cutting policy.  This means verges are often only being cut for safety reasons, for example in visibility splays, at junctions, and where pedestrians require access to the verge so as they can easily step off the road to avoid approaching traffic. It’s a sensible and pragmatic approach.

Another welcome development is very much ‘on the money’ in terms of modern environmental actions. Shetland Islands Council has begun to replace some conventional street lighting with LED equivalents. This has brought a new look to many lamp-posts around Shetland. The new ‘down lighters’ are not only fantastic when it comes to reducing light pollution, but by being deliberately dimmed after midnight they deliver a further aid to local wildlife, especially night-flying pollinators such as moths. This sympathetic action adds a whole new meaning to ‘northern lights’.

Across Scotland altering mowing regimes on public greenspaces is an action that many councils are embracing. In Shetland this has caught hold too, with some large areas of grass, which were previously cut several times during summer months, now being left to grow naturally. It’s another rather simple, basic step, but one which is potentially a fantastic boost for biodiversity. In places the only cutting is beside footpaths, with a narrow edge strip being the only intervention needed. This leaves an extended area that was previously cut on a regular cycle, undisturbed for wild birds, insects and small mammals.

A bumblebee feeding. (c) Austin Taylor

Lerwick is Shetland’s largest community. Just over 7,000 people live in the town and they will have noticed the changes made at Jubilee Flower Park.  Originally waste ground, the park was created by the council in the early 1950s and rapidly became a popular spot. The Council has recently adopted a policy in the park of no chemical use when it comes to eradicating weeds. Instead, these are manually removed by hand and the park is rapidly becoming a sanctuary for wildlife. And that’s not the only change that has been eased in. Around the perimeter of the park, walls and fences are being used for growing a wide variety of climbing plants, which of course will provide shelter and a food source for invertebrates and birds.  On a windy island the walls are much appreciated, by people and nature.

Many will be familiar with the vibrant wildflowers that pepper Shetland, such as red campion and pink sea thrift. When it comes to gardening, however, the challenge is considerable. Yet to visit Jubilee Flower Park is to wander into a scene framed by a range of impressive plants. From elder, hebe and flowering currant, through to lupins, oxeye daisy and poppies there is floral variety that bees and other pollinators will eagerly exploit. 

There is a sense that Shetland is at the start of its pollinator journey, and the actions of today will hopefully be bolstered by increasing steps to help pollinators. With further improvements and refinements the picture should look increasingly rosy.

The Shetland Isles are rightly famed as a nature haven. Understandably there is a big focus on the fantastic bird life, the thrilling marine wildlife, but there is much more besides. Shetland Islands Council is doing its bit to help pollinators in what can be a testing environment. I’m pretty sure Bobby Tulloch would have approved of their efforts. 

Links:

Insects of the Shetland Isles

The bumblebees of Bressay

Crumbling, dusty, ugly – and valuable

By Athayde Tonhasca

‘Picture to yourself everlasting bleak sand dunes with no buildings. Only rabbits find a little nourishment here; they eat a substance which quite unjustifiably goes by the name of grass. It is a sand desert where the wind always blows often howls filling the ears with sand. Between us and America, there is nothing but water a sea whose mighty waves are always raging and foaming. Now you will have some idea of the place where I am living. Without work the place would be intolerable.’  

Thus Alfred Nobel (1833-1896) – of Nobel Prize fame – described to his brother the Ardeer peninsula, the Scottish site chosen to host his British Dynamite Company in 1871. The Scottish tourism board might have looked askance at Nobel’s verdict, but Ardeer was the ideal place for the manufacture of temperamental products such as dynamite and gelignite (blasting gelatine). The peninsula was relatively isolated from skittish neighbours, yet fairly close to Glasgow ports. As a bonus, the site was covered with dunes, which were an abundant source of building material for blast walls that protected life and property against accidental explosions. 

The tip of Ardeer peninsula © Largsnaturalist, Wikimedia Commons.

By 1902, Nobel’s explosives factory was the largest in the world. Manufacture shifted to other products after the plant became part of Imperial Chemical Industries (ICI) in 1926, but production started to dwindle. By the 1980s, most operations ceased:  Ardeer train station, the dining hall, engine houses, boilers, warehouses and countless other buildings were abandoned: a large portion of the Ardeer Peninsula had become derelict. 

Today, a visitor to the once mighty Nobel Enterprises site will find crumbling sheds covered by graffiti and half swallowed by the sand, tracks of weedy tarmac, rusty pipes and barbed wire, and pieces of broken equipment scattered everywhere. Such a place definitely would not qualify as a beauty spot. But these eerie remnants have a significant ecological value.

The remains of Ardeer railway station platform © Dreamer84, Wikipedia.

Land that has been previously built on or developed such as the Nobel factory is classed as a brownfield site – as opposed to greenfield sites, which are land that has never been developed. Some brownfield sites are inhospitable places, layered with tarmac or concrete, and often contaminated with toxic chemicals. But many of these areas are not hazardous; quite the opposite. They are usually populated by patchy, thin vegetation (sometimes because of poor soils and lack of water) comprising weeds, grass and scrub; the landscape is a mixture of bare ground, temporary pools, scattered logs, stones or rubble. These post-industrial sites, old quarries, disused open mines, spoil heaps, gravel pits, and other abandoned enterprises may look like the settings of a Mad Max film, but they are great opportunities for pioneer species – those first to colonize a newly created environment. Ecologically, open ground areas function as habitats in the initial stages of succession – that is, on the way to becoming closed-canopy forests.

Abandonment kick-starts ecological succession, beginning with pioneer species and ending with an old-growth forest © Joshfn, Wikimedia Commons.

Many species benefit enormously from these semi-open spaces that are not yet taken over by strong, dominant competitors. Pollinating insects in particular have at their disposal sunny spots for basking, a variety of wildflowers for nectar- and pollen-feeding, patches of bare ground for nesting, and some solid, sheltered structure such a pile of rubble for hibernation. They have it all. Even better, these sites are mostly free from human interference – people tend to avoid them. Evolving brownfield sites have their own special name: open mosaic habitats. They are sufficiently valuable to biodiversity to be considered a category of UK priority habitats. 

A typical open mosaic habitat © Richard Croft, Wikimedia Commons.

Ardeer is an exemplar evidence of the value of open mosaic habitats. It harbours the most diverse assemblage of bees and wasps in Scotland: 113 species, including many scarce ones such as the northern colletes (Colletes floralis) and the coastal leafcutter bee (Megachile maritima). Beetles, moths and butterflies are also richly represented (Philip et al., 2020).

The hairy-saddled colletes (Colletes fodiens) is common in southern Britain, but with only two records in Scotland, one of them in Ardeer. This bee is considered vulnerable in continental Europe (European Red List of bees, 2015) © Rick Geling, Wikimedia Commons. 

By their very nature as successional habitats, brownfields are ephemeral; in 15-20 years, they are likely to be overtaken by scrub and eventually become woodland. They may not even last that long, as they are prime targets for makeovers; Ardeer itself is being considered to become a housing development, a golf course, a marina, a wind farm, or even a site for a nuclear fusion reactor. The limited aesthetic appeal of brownfields induces few objections to their re-development. But considering their value for biodiversity, their keeping and management to retain their successional nature are equally valid options for their future.

Derelict sites: dumping grounds, eyesores, a waste of space – and hotspots of biodiversity © Graham Horn, Wikimedia Commons.

Travelling into a green future

We know more than ever about how to help pollinators. Sure, there is still much to learn, concerns about the speed of change linger, but when it comes to pollinator-friendly actions we have a bank of informed and successful actions we can implement here and now.  Around Scotland’s transport network, old and new, confidence in adopting pollinator-friendly actions is taking hold.

Speaking to Nicole Tyson, Sustainability Manager, at ScotRail you get a sense that our national rail provider has met the challenge head on.  Scotrail Station Adopters have used packs of wildflower seeds (many provided by NatureScot) to improve the options for pollinator around their stations. As commuters stream in and out of stations they will increasingly catch a glimpse of pollinator-friendly steps being taken. These come in many guises, from reduced mowing regimes, and signage to explain the benefits of changes, through to banks of flower-festooned containers … these are all good news in the battle to help our hard-pressed insects. 

At stations such as Kelvindale they have taken advantage of the proximity of Dawsholm Park to improve options for insects, the installation of bee hotels near to a newly sown wildflower meadow being a fine example of trying to build a suite of actions. That juxtaposition of food and nesting sites is a sound idea and all part of the strategy to increase biodiversity across their estate. Around Pollokshaws West the removal of invasive non-native plants has been gathering apace. And at Pollokshaws, adjacent to the popular Pollok Country Park there is a feeling that another push could result in making connections that would create an extended resource for pollinators.

Speaking of connections, working with local schoolchildren is another goal at Scotrail has, and this is taking shape in helping to facilitate STEM sessions (STEM being sciences, technologies, engineering and mathematics subjects). Nature is arguably the greatest adventure playground of them all, and combining fun with learning about pollinators is an investment in our future.

Monitoring too is something that ScotRail have increasingly grasped. A recent deadwood survey, carried out with help from TCV, being a shining example.  

It’s a similarly impressive picture over at Scottish Canals.  If you have followed NatureScot’s Green Infrastructure Fund you will know that around Canal and North Gateway in Glasgow a raft of biodiversity advances have been made.  

I remember being introduced to Robert Alston, one of the driving forces in the local community, and he told me “Nature is coming back onto this site. When the initial works here were carried out we had to remove about 300 trees, but we’ve since replaced them with more than double that number, and we are going to plant more. We’ve surveyed the wildlife living here, and we’ve got deer, a range of interesting birds such as coot, moorhen, swans, heron, sparrowhawk, jays, as well as rabbits and foxes as well as various insects. In an urban context these are great for people to enjoy, and we get a sense that we have really made space for nature.  I’m particularly proud of the trees. Not only were they planted by local communities, we had the local school and nursery come and help us. That’s the way of it, and now anything we do we aim to get the local community to help us.”

But that’s just one element of a wider picture that Olivia Lassiere, Environment Manager at Scottish Canals, can proudly point to.

“Enhancement of the canal network has increasingly seen the management of vegetation to favour pollinators,” she explains. “Changes implement include the creation of wildflower-rich grasslands alongside the towpaths, and the planting and filling out of hedgerows and orchards.”

Around lowland canals visitors will have noticed that the towpath-side meadows aren’t planted and forgotten, they are supported through pollinator-friendly revised mowing regimes. There is also an aesthetic element to work around some of Scottish Canals’ network in the Central Belt which will improve pollinator provision and the look and quality of sites. That latter direction is important as it improves sites for people and contributes to growing demands for better, more attractive, neighbourhoods and increased access to nature.

In Inverness there has been a burst of activity on the banks of the Caledonian Canal. Native hedgerow and wildflower planting has complemented the grounds of the recently completed, and architecturally impressive, Treehouse community centre. Low-intensity mowing regimes to favour pollinators are increasingly a feature of canal path management on the canal banks stretching out from Inverness.

Meanwhile in Argyll users of the Crinan Canal will have been impressed by a new mowing regime which deliberately favours wildflowers. Amongst the success stories here is recognition of how to better protect a wide variety of orchids, and adapt mowing practices to better provide food plants for the local marsh fritillary population.

All of the above suggests that we are making great strides around our transport corridors to make better green corridors and larger nature networks. ScotRail and Scottish Canals are skilfully showcasing the many things we can do to help wildlife. Good news all round for our pollinators.

Find out more:

ScotRail’s Adopt a Station

Scottish Canals Heritage and Environment

Mining their own business

By Athayde Tonhasca

With a girth (Equatorial circumference) of over 40,000 km and a land mass of more than 148 million square kilometres (29% of the total; the remainder is water) planet Earth may seem like a home roomy enough to accommodate its many land-based creatures. But these figures are misleading, because all forms of terrestrial life are confined to a slim layer between the top of trees’ canopies and the bottom of aquifers. Every physical, chemical and biological process necessary for life happens within this wafer-thin coating. Gail Ashley labelled this living skin ‘the Critical Zone’. 

Earth’s critical zone. Artwork by R. Kindlimann © Chorover et al., 2007, Wikimedia Commons.

The narrow Critical Zone has an even narrower core, which is responsible for the vital water, carbon, nutrient and decomposition cycles: the soil – which is also the growing medium for the majority of plants and countless other organisms. Soil sustains life on the planet, but is also shaped by living beings such as ants, termites, beetles, earthworms, millipedes, woodlice, mites and nematodes. They degrade organic matter and help create humus, and also shuffle soil around: the uprooting of trees displaces and turns lumps of earth, moles dig and burrow, ants and termites build earthen nests above ground. This form of ecosystem engineering is known as bioturbation, which is the subject of ichnology: from the ancient Greek íkhnos (footprint), it is the study of existing and fossilized tracks and excavations made by animals. Ichnology was an obscure and fringe scientific field until Charles Darwin had a go at it. Unsurprisingly, his endeavours had enormous repercussions.   

In 1837, Darwin visited his uncle and future father-in-law, Josiah Wedgwood, who suggested that earthworms were responsible for the slow burial of chunks of marble scattered around his property (Huxley & Kettlewell, 1965. Charles Darwin and his World. Viking Press, New York). That titbit of domestic chitchat stirred Darwin’s scientific imagination, so much so that he conducted observations and experiments with earthworms on-and-off for over 40 years. His efforts culminated in his last book, published about six months before his death: The Formation of Vegetable Mould Through the Action of Worms, with Observations on their Habits. Darwin didn’t think much of it: “I have now [1881] sent to the printers the manuscript of a little book on The Formation of Vegetable Mould through the Actions of Worms. This is a subject of but small importance; and I know not whether it will interest any readers, but it has interested me.” (Barlow, 1958). He was wrong: the book was a huge success, selling as many copies as On The Origin of Species (Feller et al., 2003).

Darwin was largely responsible for changing the perception of earthworms from garden pests to major contributors to the formation and ecology of soils. Since then, other ground-living organisms have been identified as contributors to soil morphology. Among them, ants and termites are considered particularly important simply because they are spectacularly abundant; both groups comprise a huge chunk of terrestrial animals’ biomass.  

Biomass estimates for groups of animals © Eggleton, 2020.

Ants, termites and a few other ground-dwelling insects such as dung beetles transport and rearrange soil particles, affecting soil structure and the cycling of water and nutrients. So they rightfully have received a great deal of attention as ecosystem engineers. But one group is absent from the select club of bioturbation agents: bees. 

Most of us are familiar with honey bees and bumble bees, and we may assume that other bees are like them – but they are not. Of the 20,000 or so known species of bee in the world, most (~80%) don’t live in colonies; they are solitary, that is, each female constructs and provisions a nest by herself. And around 60% to 80% of them are fossorial (from the Latin fossor for ‘digger’), meaning animals adapted to digging and living underground. These bees are known as mining bees or miners. Each female’s nest consists of a tunnel that may branch into cells. For some species, tunnels can be 10 mm wide and up to 0.5 m deep. The female will stock each cell with pollen and lay an egg on it; the larva will feed on the pollen until it is ready to emerge as an adult. Collectively, mining bees (mainly from the genera Andrena, Anthophora, Amegilla, Eucera, Halictus, Lasioglossum and Melitta) make up the most important group of crop pollinators (Kleijn et al., 2015), despite spending most of their lives underground.

X-ray imaging of mining bee burrows. a, b: relatively straight, unbranched and predominantly vertical burrows of the vernal colletes (Colletes cunicularius); c, d: highly branched and curved burrows of the sharp-collared furrow bee  (Lasioglossum malachurum) © Tschanz et al., 2023.

Most mining bees, like those in the genus Colletes, produce a resin that becomes a transparent, waterproof film when exposed to the air. Female bees brush this glandular secretion on the walls of the brood cells to protect them against excess moisture and possibly against pathogens. This feature explains why these bees are known as plasterer bees, cellophane bees, or polyester bees. Other species line their nests with petals, leaves, pebbles or other materials. Besides protecting the brood, these home improvements help to uphold the nest structure, so that air and water keep flowing along the tunnels long after the emerging bees are gone.

Brood cells of a cellophane bee © Delaplane, 2010.

A solitary mining bee is no match for the digging capacity of termite or ant colonies, but the term ‘solitary’ is deceiving. Each bee builds her own nest, but many species nest close to each other, perhaps to take advantage of relatively scarce good spots. These nest aggregations can be massive: the heather colletes (Colletes succinctus) can reach concentrations of 80,000 tightly packed nests along a 100-m stretch. These gatherings give the impression that bees are swarming: watch them going at full tilt.

A female heather colletes © gailhampshire, Wikimedia Commons.

Heather colletes aggregations may seem overcrowded, but they are sleepy villages when compared to those put together by Calliopsis pugionis: they can reach over 1,600 nests/m² (Visscher & Danforth, 1993). Mining bees’ relentless burrowing and tunnelling produce one important by-product: enormous volumes of spoil. 

In temperate areas, earthworms can deposit 10- 50 t/ha of castings (soil-enriched poo) on the soil surface annually, while ants and termites move 1- 5 t/ha of soil, reaching 10 to 50 t/ha in some instances (Wilkinson et al., 2009). These figures do not impress the alkali bee (Nomia melanderi), a prodigious soil engineer in its native deserts and semi-arid areas of the western United States. One gigantic colony, estimated to house around nine million bees, dug out 96 t of soil to the surface in one year. Much of this earth is taken away by wind and rain, which would result in a loss of 4 cm of soil surface in 50 years (Cane, 2003). In Japan, Andrena prostimias deposited 27 t/ha of soil in a temple’s garden. The volume does not seem that impressive until we learn that the excavation was completed in one week (Watanabe, 1998).

A female alkali bee by her nest and a concentration of nests © James Cane, United States Forest Service.

Bees are hardly ever considered soil organisms, but that’s a gross oversight. Thanks to their burrowing activity, mining bees are likely to contribute to nutrient cycling, water storage, soil structure and atmospheric composition: their inclusion in the roll of bioturbation agents is much justified. And you thought they only contributed to ecosystem functioning by being great pollinators. 

A wee earth-digger machine: an ashy mining bee (Andrena cineraria) arriving home with a load of pollen © Orangeaurochs, Wikimedia Commons.