Moths: some food for thought

By Athayde Tonhasca

A bear in a blog about pollinators? Well, read on.

A grizzly bear ©Tony Hisgett, Wikipedia Creative Commons

As any fan of Yogi Bear & Boo Boo knows, food is the main preoccupation of brown bears (Ursus arctos). They need to accumulate calories to survive the winter, so most of their waking hours are spent searching for something to eat. Almost anything of nutritional value would do: flowering plants, grasses, roots, tubers, berries, insects, small rodents, carrion, roadkill or human refuse. For the grizzly bear subspecies (Ursus arctos horribilis), finding food in the cold, harsh mountainous areas of the American states of Montana and Wyoming can be particularly tricky. But those bears can rely on one abundant and nutritious menu item: army cutworm moths (Euxoa auxiliaris).

Grizzly bear home in the mountains of Montana/Wyoming © Wikipedia Creative Commons, and a bear searching for moths among rocks © https://www.yellowstonegate.com.

This moth, also known as miller moth, breeds in open grassland and farmland across the western United States. The adults migrate to higher elevations during the summer, where they feed on nectar from several plant species at night and gather under rocks during daytime. These moth aggregations are easy meals for a grizzly bear, which can put away 40,000 moths/day. A moth meal, however large, may sound insufficient for a creature weighing 180 to 360 kg (males). Until we learn that army cutworm moths are the fattest animals on record: up to 72% of their body weight is fat (the blue whale comes in at a distant 35%). Moths need this much fat as an energy source for their migration flights, which can cover 100 km/day. Grizzlies are very appreciative of these flying titbits of fat: their energy content average 7.0 kcal/g dry matter, which is more than blueberries (4.5), ground squirrels (5.3), trout (5.7) or pine nuts (6.5) can offer.

An army cutworm moth: a greasy meal to put any chippy to shame © Robert Webster, Wikipedia Creative Commons

Grizzlies are just a tiny minority of the animals that feed on insects. Insectivorous bats consume 30–100% of their body weight in food each night. Tits (Parus major and P. caeruleus) bring hundreds of caterpillars to their nestlings per day, at rates that reach almost one a minute during peak demand. Most birds are insectivorous or eat insects and other arthropods at some point in their development, and they are hungry: worldwide, birds eat roughly 400 million metric tons of prey biomass/year. This mindboggling figure corresponds to the annual energy consumption of a city the size of New York City. It’s not only birds and bats: other mammals, frogs and lizards feed on a variety of insects and spiders. Caterpillars, flies and beetles are particularly important in temperate forests and agricultural habitats. 

When we talk about biodiversity, we usually think about the variety of species, their distribution and interactions. But numbers of individuals are important too, as the size of a population dictates its productivity and determines whether a species has what it takes to make a difference for ecological services such as nutrient cycling, flood regulation, water purification and pollination. But simply counting life on Earth gives us a warped view of species’ relative importance for the obvious reason that size varies tremendously: lots of tiny organisms have much less impact than fewer but bigger ones. For a more useful comparison, life could be quantified as biomass. That’s exactly what a group of researchers did: they put together hundreds of studies to estimate the amount of carbon – the building-block of life and a proxy for biomass – produced by each of the major taxonomic groups. 

Unsurprisingly, plants came first, accounting for more than 81% of all of the planet’s biomass. Not so unsurprisingly, bacteria came second, with ~13%. Animals amount to just 3.6%. Plants rule the Earth, but arthropods (mostly insects, spiders and crustaceans) dominate animal life. Take a good look at the figure below. If you put together each human being, elephant, whale, cow, bird, and every other domestic animal, wild bird or mammal in the planet, it’s not enough to trump terrestrial arthropods. These figures help us put our importance in perspective.

Estimated relative biomass of some animal taxa. Data from Bar-On et al. 2018. The biomass distribution on Earth. PNAS, http://www.pnas.org/content/115/25/6506.

We don’t have data specifically for insects, even less so for moths. But considering their species richness, abundance and relative large size, it is reasonable to assume that sustaining some grizzlies in American mountains is just a small part of their contribution to the functioning of ecosystems around the world. With time and more data, we eventually should discover other secrets from the secretive moths. 

Buzzing with success

At the tail end of last year the Keep Scotland Beautiful, It’s Your Neighbourhood, pollinator-friendly award went to Bonnie Dundee. It was a close call. The standard of entries was exceptional, and in today’s blog we celebrate the many pollinator-focussed projects taking place up and down the country.

Here’s a look at the highlights that added up to good news for bees, hoverflies, and other pollinators. And all this despite the difficulties of creating during a pandemic.

In Edinburgh, The Friends of Saughton Park planted a ‘wild’ orchard to go alongside their ‘trained’ orchard in their walled garden. With the addition of fruit bushes, native hedging and a dash of wildflower seeding you can see that this group went out of their way to offer pollinators a helping hand. 

Not too far from Saughton lies the Drylaw Neighbourhood Centre. A mix of wildflower meadow, an orchard, fruit and vegetable areas – and there are plans afoot to increase the wildflower meadow considerably. There is a lovely social element to the work in Drylaw with social interaction and teamwork lying at the heart of the ambitious plans here.

Starbank Park lies in the Newhaven area of Edinburgh. Pollinator-friendly planting has seen a switch from bedding plants to annuals, and the cosmos, nasturtiums and marigolds went down well with pollinators last year. There has been an emphasis on community involvement, which included the establishment of a seed library so as folk could do their bit for pollinators in their own gardens, patios and window boxes. Leaving dandelions to flower in the park for hungry early bumblebees was another popular and highly beneficial move.

North Edinburgh Arts group has a strong focus on butterflies, and do this incredibly well. By providing nectar-rich flowers, new wildflower beds, and generously handing out batches of seeds they have encouraged the local community to get involved in both helping butterflies specifically and taking a range of pollinator-friendly actions generally.

Glasgow of course has the ‘Dear Green Place’ name and we weren’t surprised to get a clutch of high standard entries from Scotland’s biggest city.

Grow 73, a charity based in Rutherglen, has the aim of local growing, increasing biodiversity, and improving the local environment. Their community garden at Overtoun Park is their hub but a project to create a green pollinator pathway from Rutherglen train station through to Cathkin Braes shows they are thinking big. Planting around the station, and in Rutherglen Main Street, has already helped pollinators and in contributing to national recording schemes they have helped establish a clear picture of which insects, and in particular pollinators, are present in their area.

Over at Yorkhill there was great news.  Solitary bee hotels were installed and used, over 900 spring bulbs were planted, and seasonal forage was planned to ensure pollinator resource from early spring to late autumn. Sensitively managed wildflower strips and contributions to key pollinator recording activities rounded off a very impressive body of pollinator friendly work. In the heart of Glasgow it’s clear the dedication of this highly skilled team has revitalised the area for pollinators.

The North Lanarkshire Corridor Community are transforming the greenspaces between Muirhead and Chryston. Working in partnership with the Seven Loch project and Paths for All they have raised awareness of pollinators and planted pollinator-friendly shrubs and wildflowers. Around Gartcosh railway station the group went with a range of native trees and shrubs to create a pollinator patch that they hope to replicate in Chryston in due course.

One-hundred and thirty miles north, in Aberdeen, Denburn Tennant’s Association make the most of a small garden in the busy centre of town next to the theatre. The community here describes itself as elderly, but the activities suggested a youthful outlook as they realised a mix of flower and vegetable planting which makes the area around this multi-storey high rise much more pleasant for pollinators and people alike.

Just outside the Granite City lies Cove, and here the local Woodland Trust have planted a range of trees and reinstated a local hedgerow. Allied to the addition of wildflower planting they have crafted a lovely walk that has been a boon to the local community. The addition of a sensory garden, with a range of herbs, has attracted a diverse range of pollinators, so all in all a very nature-rich territory has been created.

It’s a fair hike from Aberdeen to Duns, but the town in the Scottish Borders is of a like mind when it comes to pollinators. The focus of the cleverly named ‘Abundant Borders’ group is partly local food production and the vital role our pollinators play in that process, and partly skilled habitat creation. A new wildflower meadow on the Todlaw Estate was a roaring success. Sustainable and organic growing methods allied to community engagement, and some rich ‘wild areas’, have created an excellent mix.

Watch us Grow also lived up to their name.  When they noticed that their raised beds weren’t performing as well as they used to, they quickly realised that they were lacking in pollinators too. A bit of rewilding was in order, and soon wildflowers and pollinators were back. Given the loss of the bulk of 2020 to restrictions of one kind and another the group are happy to report that nature has got on with the job and that the site is now a pollinator (and other wildlife) haven.

It is incredibly heartening at a time when we face the twin perils of biodiversity loss and climate change to find so many community groups consistently pursuing a pollinator friendly agenda. By rolling up their sleeves, and doing their bit in their patch, these highly motivated groups deliver for pollinators and persuade others to follow suit.

A bit of slashing now and then: the lines are open for pollinators

by Athayde Tonhasca 

In 1926, the government body Central Electricity Board set out to create a nationwide electrical grid to bring cheap power for everyone. This was the biggest building project that Britain had ever seen, and soon steel pylons and transmission lines began popping up all over the landscape. Many people didn’t like what they saw. In 1929, Rudyard Kipling and John Maynard Keynes co-signed a letter to The Times protesting the construction of pylons, noting they were ‘the permanent disfigurement of a familiar feature of the English landscape.’ The pylon’s designer, architect Sir Reginald Blomfield, fired back: ‘Anyone who has seen these strange masts and lines striding across the country, ignoring all obstacles in their strenuous march, can realise without a great effort of imagination that [they] have an element of romance of their own. The wise man does not tilt at windmills – one may not like it, but the world moves on.’

You may side with Kipling and Keynes or Blomfield in this aesthetics vs utility debate, but transmission lines are here to stay, for a while at least. The British grid of high-voltage lines from power stations alone runs for ~25,000 km; adding to that several thousand kilometres of regional networks, power lines have become part of our landscape.

Transmission corridors, similar to roadsides and railway embankments, are routinely mowed, clear-cut or treated with herbicides to prevent the encroachment of trees and dense vegetation. These practices are viewed as necessary evils by the public and some conservationists; but, with the right touch, they create opportunities for bees and other pollinators.   

In ecology, ‘succession’ is the process by which a natural area changes after a disturbance or following the initial colonization of a new place. In terrestrial habitats, early succession refers to the period before they become enclosed by trees’ canopy. Weedy areas, grasslands, old fields or pastures, shrub thickets and young forests are all examples of early successional habitats. And so are transmission corridors, where maintenance crews prevent succession from reaching its equilibrium point or climax by cutting down the vegetation. 

Plant succession © OpenStax Biology, Wikipedia Creative Commons

It turns out that habitats in the early successional stages are excellent for bees. These areas offer a steady supply of nectar and pollen over much of the year, as opposed to forested areas where blooms peak in spring and are limited by the shaded canopy from midsummer on. The large majority of bee species nest in the ground; they need patches of bare soil of the right texture and moisture, and close to their food plants. Successional habitats are just the right place for this combination of features. So it’s not surprising that bee abundance and species richness decreases with increasing forest cover.

Lots of flowers, nesting/hibernation sites & sunshine: perfect for bees © Trevor Rickard, Wikipedia Creative Commons

In the northeastern United States, power companies have been maintaining power lines under Integrated Vegetation Management (IVM) since the 1950s with the objective of protecting the grid while providing habitat for threatened plants and animals. It sounds fancy, but essentially IVM comprises five-year cycles of selectively killing trees (mechanically or with herbicides), with no mowing or widespread spraying of herbicides. These simple techniques create a mosaic of meadow, herbaceous plants and shrubs, which have proved to be good for many reptiles, amphibians, birds, small mammals, and bees. A comprehensive survey along 140 km of a transmission line in New England revealed that the sunny, open corridors held nearly 10 times the number of bees and twice the number of bee species as compared to adjacent forested areas. Not only that, about half the known species for the region, including some rarities, were found in the survey. No comparable study exists in the UK, but we could expect similar effects. The ecological conditions are different – bracken control, for example, could be a greater challenge – but our bees would also benefit from vegetation management along power line corridors.   

A power line corridor, great habitat for bees © Humphrey Bolton, Wikipedia Creative Commons

Nobody likes the sight of a transmission line. But those ugly and gloomy steel towers and cables can be turned into pollinator and wildlife havens. All it takes is goodwill and some imaginative work. The lights will stay on, and there will more bees around.    

No West Lothian question

Wildflower meadows are a haven for wildlife. For hard-pressed pollinators they are a fantastic resource. People love them too, and when in full bloom they are one of our most popular habitats. Creating and regenerating them is a growing tactic in the battle to help biodiversity.

Beechwood Park, July 2019

Given the range of nectar- and pollen-rich species that are found in meadows it’s fantastic that council such as West Lothian are doing their bit to restore and establish these habitats. When they are buzzing with insects and in full bloom wildflower meadows are a sight to behold. Just like Bernie Sanders woollen mittens, they have a very practical purpose and they look good.

It’s reckoned we have lost somewhere in the region of 97% of our wildflower meadows since the 1930s. That 97% figures never becomes any less eye-watering in being repeated.

Working closely together West Lothian Council and Buglife Scotland have seen the popular B-Lines project as an ideal vehicle to deliver important change. Tapping into £40,000 funding from The National Lottery Heritage Fund, and a further £13,000 investment from West Lothian Council, has enabled an ambitious project to take hold.

Buglife’s B-Lines are a roaring success. In this instance they will create 4.8ha of wildflower meadows across public parks in West Lothian. That mosaic approach is good practice which provides stepping stones for pollinators to travel from one area to another.

But creating meadows is one thing, getting local communities to embrace them through all their stages (for let’s be honest they don’t always look like a floral picture-postcard) means delivering workshops with schools and community groups to raise awareness of our vital pollinating insects and the hugely beneficial role of wildflower meadows. This ‘show and tell’ approach increases public support.

Wildflower meadows are being created in two ways. Firstly there is the method that relies on rotovating areas of amenity grassland, and then sowing wildflower seed by hand in autumn or early spring

The second method is more about identifying sites with potential and applying sympathetic management to bring meadows back from the brink.  Where traces of wildflower meadows or patches are found the route to success means changing the maintenance regime and encouraging wildflower species to once again grow naturally.

But whether it is a planting or nurturing approach all of the meadows being created are perennial meadows, meaning the plants should, with any little luck, return each spring (unlike annual meadows, which have to re-seed).

Consideration is always given to the often differing local conditions. Meadows on wetter soils are sown with a ‘wet meadow’ mix of seeds, with species that thrive in wet conditions. All seeds are of Scottish origin with the intention to plant them within their native range. That usually ensures success, but as with all things in nature there are few guarantees and from year to year things can change.

However, it is agreed that the key to a meadow thriving beyond its initial establishment is sympathetic meadow management.

West Lothian Council and Buglife are clear on what is required and stress that there is no ‘plant and walk away’ solution.

All meadows are cut once a year, usually in autumn although sometimes in early spring. This annual cut prevents grasses, docks, even self-seeded trees, crowding out the wildflowers which would in time accelerate a return to scrubland. To support as many insects as possible, cutting must come after all the plants have stopped flowering – hence either a late or very early cut.

Furthermore, for the cut to have real value must see all the cut material (arisings) removed.

Given that West Lothian Council want to encourage as much floral variety as possible this is a follow up action that is crucial. If arisings are left on the ground, they fertilise the soil, increase nutrients, and cause meadows to become dominated by one species.

By removing the arisings each year, nutrients are reduced, the dominant species weakened and all wildflower species have a better chance of competing for survival. It is for this reason too that fertiliser should never be used on wildflower meadows.

The meadow’s floral friend ‘Yellow Rattle’ has long been recognised as an ally in the battle to bring back meadows. This is a parasitic plant that feeds off grass, weakening it and allowing the other wildflowers to survive. West Lothian Council try to use this plant wherever the conditions permit. But, as with most gardening, all wildflower meadows in parks are an ongoing experiment!

If reading about the work going on in creating West Lothian’s B-Lines has made you hanker to go and view it close up then here is a list of some of their latest sites:

• Beechwood Park – Linlithgow;
• Rosemount Park – Linlithgow;
• Learmonth Gardens – Linlithgow;
• Almond Park – Craigshill, Livingston;
• Balbardie Park – Bathgate;
• Eliburn Park – Eliburn Livingston

And if you want to get a complete ‘before and after’ sense of the process then, come summer, you could head along to one of these parks: Stewartfeld in Broxburn,  or either Almondvale, Howden or Livingston Village in Livingston.

Eliburn, before and after the wildflower meadow works

You may be surprised to see that all of these meadows have wooden stakes placed around them for the first growing season. That is simply to protect that site and remind everyone that they exist and to prevent mowers from cutting them! That may seem a very cautious step, but it is surprising how there can be slips ups between the planting of a meadow and the management. All it takes is for a change in personnel, or a contractors looking to follow a previous year’s approach, and the good work can be undone unintentionally. 

West Lothian Council are quick to point out, quite rightly, that there are multifunctional benefits in allowing some areas of grass to grow longer.  These benefits include not only contributing to the health and wellbeing of residents who will likely enjoy the return of nature, but in reducing the flow of rainwater over the ground and storing rainwater. This helps to stop drains overflowing, provides food and habitats for small mammals and amphibians and reduces erosion through run off (especially on slopes and very wet areas).

They haven’t forgotten the opportunity bulbs offer either. There have been various mass bulb planting exercises carried out here. Three areas in Broxburn’s parks have been planted by machine with tens of thousands of bulbs, this in turn will provide flowers from February right through to June. It’s a low maintenance route to pollinator-friendly success giving a vital early season feeding source for emerging pollinators. What’s more these areas will probably only need cutting a couple of week after the last flowers have died off.

Finally, there is a climate change angle we should celebrate. Rain gardens are being installed in West Lothian’s Council area and these are low maintenance, planted areas, designed to hold water when it rains, which then allows the water to slowly seep away into the soil or evaporate over a long time. This help to relieve pressure on the drainage system when it rains heavily, reduces the likelihood of flash flooding, and is good for wildlife. These dry out when there’s no rain, and include drainage swales and bog gardens.

So no West Lothian question here – good things ARE happening in West Lothian.

Those vexing but intriguing cryptic bees

By Athayde Tonhasca

Imagine it is springtime, you are enjoying the sunshine in a beautiful garden, camera/phone in hand, ready to start your list of pollinating species (a New Year’s resolution). Lo and behold, a bumble bee is feeding on a flower very close to you. The lighting is good, there is no wind, and she waits politely for you to take several perfect shots. Back at home, you get your guide book to identify the bee. By cross-referencing colour and band patterns, you conclude it’s a buff-tailed bumble bee (Bombus terrestris). Before jotting it down on your field notebook (another New Year’s resolution), you check it again. Now you think it looks more like a white-tailed (B. lucorum). You dig in further to find two additional candidates: the cryptic (B. cryptarum) and the Northern white-tailed bumble bee (B. magnus): all looking very much the same. You begin to wonder if you should stick to a list of butterflies.

Your frustration would be understandable and explainable. The colour patterns of many bumble bees are variable within and between populations, so that some forms may look very much like some other species. To complicate things, many sympatric bumble bee species – i.e., occurring in the same area – are similar to each other. This feature is believed to be a manifestation of Mullerian (or Müllerian) mimicry, which happens when two or more species harmful to predators converge to a similar appearance. This reinforces the message to predators to avoid that colour pattern for their own good, which gives mimics an evolutionary advantage. 

Bombus lucorum/cryptarum/magnus? A vexing problem © Ivar Leidus, Wikipedia Creative Commons

Experienced bumble bee enthusiasts can tell the buff-tailed from the lookalikes, but the white-tailed, cryptic and Northern white-tailed bumble bees are morphologically indistinguishable from each other: we need genetic analyses to tell them apart. So it is not surprising that Bombus lucorum has been given more than 180 other scientific names over the years, all because of different taxonomic interpretations. To sort out this Gordian knot, taxonomists refer to the three species collectively as Bombus lucorum sensu lato (‘in the broad sense’), abbreviated as s.l. or sens. lat. As opposed to Bombus lucorum sensu stricto (‘in the strict sense’), abbreviated as s.s. or sens. str., when we want to refer to this species alone. Bombus lucorum s.l. is not an isolated case: of the 250 or so bumble bee species in the world, only a handful are easily and unquestionably identified.

These taxonomic spitting images are known as cryptic species, sibling species, or as a species complex. With the fast expanding availability of genetic techniques, we are finding out that cryptic species are much more common among insects than previously thought. For example, DNA barcode analyses have shown that the two-barred flasher butterfly (Astraptes fulgerator), which ranges from the United States to Argentina, comprises three to seven species (the vagueness on the number reminds us that genetic tools are not a straightforward alternative to traditional taxonomy).

Astraptes fulgerator s.l.: 3, 4, 5, 6 or 7 species. © Chinmayisk, Wikipedia Creative Commons

Cryptic species have profound consequences for conservation. A species cannot be properly protected if we can’t tell exactly what it is, what it does and where it is. Because of these uncertainties, the conservation status of B. cryptarum and B. magnus can’t be assessed: they linger in the Data Deficient limbo of the IUCN Red List of threatened species. Moreover, biodiversity estimates may be hugely underestimated, and conservation efforts may be inadequate because true species richness and ecological interactions could be hidden. There are implications for human health and agriculture as well. There are over 3,500 species of mosquitoes of the order Culicidae, of which an alarming number are cryptic: telling them apart is essential because a few are vectors of malaria and other diseases. The same applies to Ceratitis fruit flies, some of which are serious pest of fruit crops. 

It would be short-sighted to see cryptic species only as a taxonomic headache. In fact they tell us life on Earth is much more complex and diverse than we thought. DNA analyses have revealed new species of bats, chameleons, lemurs and even giraffes. So we can expect a deluge of new plants, fungi, insects and other less studied organisms when – and if – their genetic profiles are investigated.

Approximately 1.5 million species have been described, but this figure is thought to be a gross underestimate. With cryptic species at play, the true number is anybody’s guess. 

The complexities of species complexes notwithstanding, bumble bee observers have reasons to persevere. Much of species identifications involve ecological information such as location, time of the year, plants visited, and even behaviour. Naming species this way is trickier, but also more challenging and educational. And those who become stuck in their efforts to identify bees should be philosophical: by tangling with cryptic species, they are experiencing some of the mysteries and wonders of nature.

Things can only get better

The infrastructure in and around our built environment can help society tackle issues as crucial as biodiversity loss and climate change.  Raingardens are an enlightened infrastructure solution offering multiple benefits.  The good news is that Scotland has shown a keen interest in the concept of raingardens, as a standard method of dealing with surface water management, flood alleviation and greenspace creation.

It is probably safe to say that in Scotland we take a steer from successful projects based in Melbourne, Philadelphia and Portland, where there has been a growing acceptance of the value of raingardens as a viable answer to water management and environmental challenges.

The Kinross-shire Civic Trust Raingardens Challenge is an ambitious project which seeks to harness the potential of using greenspace wisely in our town and villages to create a bank of raingardens which are valuable landscape features whilst soaking up rainfall draining off roads, roofs and other impervious areas. 

Raingardens are certainly as desirable from a practical perspective as they are an aesthetic one. Incidences of flash flooding have increased alarmingly in recent years, and a deal of concern has been centred on the significant impact of the growth of hard landscaping approaches in domestic and industrial settings.

Raingardens are vegetated features designed to slow down and use rainwater. They use plants, soils and the landscape to hold onto the rainwater and then slowly release it. They also help reduce the amount of water which gets to the sewer. Some water is taken up by the plants, some rainwater finds its way back down into the ground, and some water will evaporate. Raingardens also help clean the water, which may have picked up dirt from the roofs and roads.

The objective of the Raingarden Challenge encompasses improvements such as adding wildflower and grassland areas along with more traditional planting with a wetland emphasis.  This multi-layered response is sensibly flexible to suit individual circumstances, but the consistent goal is the need to soften a built environment which at its most harsh can deliver a landscape often almost devoid of plants.  Sympathetically planted and naturally-sculpted landscapes can effectively absorb rainfall runoff, thus contributing notably to managing increasing flood risks.  When carefully designed, raingardens visibly help mitigate the potential impact of flash floods which are a disturbing reality as climate change bites home.

There is general acceptance now that the presence of planted areas assists the absorption of rainfall draining quickly from a hard-surface. Indeed a good example of this approach can be found in the Kinross area where wildflower swale has been installed at the edge of the link road in West Kinross. The consensus is that the impact is extremely positive.

The Kinross-shire Raingardens Challenge has an admirable sense of proportion and realism. They know they can’t deliver everything working in isolation. They are thus actively engaging with Perth and Kinross Council, local businesses, and individuals to see if they can encourage partners to consider installing raingardens or making modifications to their drainage systems which would deliver improved rainwater management. 

To this end they have invited business to get in touch with them if they suffer from a regularly flooded car park, for example, with a view to persuading the next solution to avoid simply going for a conventional reinstatement by exploring options to see if there is a viable raingarden solution.

Likewise if residents notice a road gully which is regularly failing, the group suggests communities contact their local councillors to probe the possibility of considering a raingarden instead.

Kinross-shire folks can certainly be persuasive. They recently worked with the famous Loch Leven’s Larder on an innovative way to transform the popular visitor attraction’s carpark into a series of small raingardens, and are actively working with the Kinross Estate (particularly the Green Hotel in Kinross) and others.  

Progress has been delayed by COVID, but agreements to pick up a.s.a.p. are encouraging. The Kinross-shire initiative is following a broad and inclusive definition of a raingarden: “ green infrastructure feature designed to accept rainfall runoff”.  Solutions are best when the features are linked to more optimal green features (grassland, hedgerows or woodland for example). Verdant verges can complement a roadside swale, especially if forming a gentle fringe to merge into the swale. In a recent survey some of the area’s local country road verges fell under the microscope. 

The results were interesting. In Carnbo (near Crook of Devon) 96 species were counted along a section of the Gelvan road, and over 70 species were logged near Westfield. In both examples water was able to run off tarmac into various verge types and several of the ditches examined were found to contain marsh species and tall grass species.

There is an admirable realism rooted in the Kinross-shire Raingardens project. The group are keen to acknowledge and celebrate good practice by participating businesses and households. Through a series of awards the intention is to convince more and more observers to see the value of going down this route. Nevertheless, not every green infrastructure project succeeds first time, or indeed every time, and this is acknowledged by a commitment to include ongoing managements and restoration of failed projects in their approach.

When the group issued a newsletter article recently they ran with the catchy headline of “I beg your pardon, I never promised you a raingarden”.  Based on their practical approach and sound vision they might need to dust down another upbeat song title– perhaps, the line from D:Reams ‘Things can only get better’ might appeal?

Further Reading:

Find out more from Brian D’Arcy via b.darcy@btinternet.com see NatureScot’s guidance on including green infrastructure solutions in the Planning and Construction sector 

And the joint WWT/RSPB publication on SuDS: 

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Images courtesy and copyright of Brian D’Arcy

Coming soon to an ivy near you

By Athayde Tonhasca

In 1993, two German entomologists came across some unusual specimens of plasterer bees – their epithet comes from their use of saliva to smooth over and strengthen the walls of their underground nests: taxonomically, they belong to the genus Colletes. Those specimens, collected in Germany and Croatia, didn’t seem to fit in with any known plasterer bee. It turns out the entomologists were dealing with a new species. Because the bee was found collecting pollen from ivy (Hedera helix), they named it Colletes hederae. Discovering a new European species of bee is unusual, as the fauna is well known and recorded. The ivy plasterer bee or just ivy bee escaped detection for so long because it takes microscopic examination to tell it apart from similar species.

An ivy bee on an ivy flower ©gailhampshire, Wikipedia Creative Commons

Few bee species have experienced such a meteoric career. Unknown until 1993, the ivy bee has been dispersing rapidly since then, at rates of 6- to 7-fold between 2001 and 2010, with records from all over Europe. It arrived in Dorset in 2001, reaching Wales and northern England in 2016. It is still moving northwards, so may soon be recorded in Scotland. The UK Bees, Wasps and Ants Recording Society (BWARS) is plotting and monitoring the spread of the ivy bee in Britain with their online recording platform for sightings submitted by the public. 

The ivy bee is not only spreading out fast, but its numbers are increasing rapidly too. They nest close to each other in soft, crumbly banks and cliffs, and aggregations of thousands of bees have been reported in southern England. This rate of expansion is a bit unusual, since most bees are phylopatric, that is, they generally remain in or return to the same nesting site across generations (Philopatry, from the Greek philo, ‘liking, loving’ and patra, ‘fatherland’).

We don’t know the reasons for such a dramatic population growth, but abundance of food must have contributed considerably. 

The ivy bee is the last to emerge among all British solitary bees, and the only autumn species. It is active from late August to late October, occasionally stretching to the beginning of November, when most other species are no longer collecting nectar or pollen. August to November is ivy´s main flowering period, so the bee has no problem finding food. The ivy bee takes pollen from other plants, but over 80% of it comes from ivy. Being a pollen specialist can be tricky because food may be locally scarce. This is not the case when the host plant is all over the place, and may even become more widespread thanks to an increase in summer temperatures.

Ivy, source of pollen and nectar for many insects ©Lorne Gill / NatureScot

The absence of natural enemies in the newly occupied areas is another possible contributor to the ivy bee’s success. In continental Europe, the variegated cuckoo bee Epeolus fallax and the ivy bee blister beetle (Stenoria analis) invade ivy bees’ nest to eat their eggs and stored food, so their host may not do so well if these nest parasites were around. Unfortunately for the ivy bee, they are likely to follow their host into Britain.   

Introduced species may be highly disruptive by outcompeting the native fauna, or by harming it or the environment some other way. These are cases of invasive species. We usually don’t see bees as belonging to this category of undesirables, but they might: the buff-tailed bumble bee (Bombus terrestris) and the honey bee (Apis mellifera) have caused environmental damage when introduced outside their native ranges. But most introductions are neutral: species move to new places or are moved naturally all the time (by the wind or currents, carried by birds, etc.), with no significant consequences. The ivy bee is likely to expand its distribution in Britain and eventually settle in, its limits imposed by food, weather, natural enemies, or a combination of factors. But it is here to stay: our bee fauna has gained one more species. 

The cuckoo bee Epeolus fallax may check the expansion of the ivy bee. © Monique – CC BY NC license, https://www.galerie-insecte.org

Let It Grow, Let It Grow …

Given that we are in winter it is perhaps appropriate that our blog this week looks at a ‘blizzard’ of activity.  However, the glance is not at the weather but at a whirl of pollinator-friendly actions. The focus is on the many steps taking place in Angus, and it can be a challenge just listing them. From managing verges and council land, through to engaging with a range of volunteers and species groups, there is a host of positive projects to celebrate.

The fate of our verges has never been more earnestly debated or open to transformation.

Council Roads Service teams work with local communities, environmental organisations and botanists on how best to maintain and encourage species-rich verges. The introduction of a rural grass cutting regime now means there are just two cuts on A, B and C class roads per year, this results in a 1-metre floral and grassland swathe with allowances made for safe sight lines and inside of bends. The relaxed mowing regime is even more pronounced on unclassified roads where there is only one cut per year.

If you would like to see how this looks at a future date then a good spot to view might be the area around the A92 outside the Scottish Wildlife Trust’s Montrose Basin centre. There the grassy areas are managed specifically for conservation purposes. That’s a winning partnership that inspired other actions.

Angus Council has worked recently with BEAR Scotland to protect plants such as northern marsh orchid and cowslip on slip-ways off the A90. They do this by following the guidance given in the Plantlife ‘Good Verge Guide’ and they are thus well able to deliver on the visionary strap line for that booklet – ‘A different approach to managing our waysides and verges’.

Few know a verge more intimately than a local community who see it year-round and year-on-year. The innovative ‘Shaping Angus’ online community consultation platform hosts a dedicated map-based wildflower project  providing a unique opportunity for local communities to identify their favourite local wildflower rich verges and alert the council to these sites.

The Council is quick to acknowledge the value of networking with many partners.  Close to home are the highly-respected Tayside Biodiversity Partnership, whilst equally helpful are national experts such as Butterfly Conservation.  Bringing a variety of expertise around the table to work with community groups, local golf courses and landowners makes projects stronger and the desire to build knowledge through skilled surveying, monitoring and delivering habitat restoration work feasible. 

And the level of local expertise here is increasingly impressive.

In 2019 the Angus project ‘Back from the Brink – Saving our Small Blue’ won two national accolades – a Scotland Community Initiative Award and the prestigious Association of Local Government Ecologists 25th Anniversary Biodiversity Award. And since 2019 the project hasn’t rested on its laurels.

Surveying and kidney vetch planting have continued in 2020 and plans are being developed to launch the ‘Small Blue Way’ – an Angus coastal path highlighting spots to see small blue butterflies along its 35 plus miles. There will also be opportunities to adopt or sponsor sites. This should facilitate more regular monitoring, conservation work and local tourism opportunities.

Habitat enhancement was also the theme at Newtyle Primary School pond in 2020 when a pollinator garden containing more than 200 plants was created by pupils and volunteers. That’s a smart approach, delivering benefits in the short term, and nurturing future environmental supporters.

Indeed there is barely a town or village in Angus that isn’t involved in some level of biodiversity improvement.  Council services work closely with communities, as the list below reveals:

• Monifieth Ecoforce planted wildflowers in the orchard at West End Community Meadow. Further planting took place in the Beach Garden project at Monifieth Seafront.
• Colourful Carnoustie created wildflower beds on the seafront and plant and maintain planters throughout the town centre. The Seafront Rest Garden, funded by the Open Legacy Fund included tree felling, the clearing of shrub beds and replanting.
• Keptie Friends in Arbroath plant annual wildflower areas to attract a variety of pollinators; willow hurdles have been established around the pond.
• Fit O’ The Toon Residents Association in Arbroath created a strip of wildflowers along the burn at Old Shore Head with a mixture of perennials and annuals. Also, in Arbroath, Arbroath in Bloom provided floral displays throughout the town.
• Blooming Montrose installed planters and hanging baskets in High Street and other Montrose locations and Montrose Bay Community Group installed a floral display in a boat on the seafront overlooking Montrose Bay.
• Inch Maintenance and Preservation Society in Brechin seeded native wildflowers along Skinner’s Burn.
• Forfar in Flower established flowerbeds in Boyle Park and continued to look after a series of beds and planters throughout Forfar.

Special mention should be made of ‘The Montrose Space for Nature Pilot’ which was developed by Council staff and local native wildflower seed producers Scotia Seeds. The project involves a change in the grass cutting and herbicide application regimes in open spaces at three sites in Montrose to allow wildflower regeneration. A two-kilometre section of cycle path is reducing from 16 to 2 cuts per year, with the final cut and lift in late autumn. This will reduce nutrient load on the verges allowing wildflowers and pollinators to thrive. In fact the pilot project goes beyond amenity grassland management also focusing on wildflower meadow management in disused kirkyards.

The project has enhanced biodiversity by allowing regeneration of native grassland meadows and has improved the food source for pollinators … so much so it will be extended to Arbroath in 2021.

Scotia Seeds deserve special thanks for having funded information panels that will provide on site details about the project. Local people of all ages were asked to send in drawings of local wildlife and wildflowers and a number have been selected for use on the engaging information panels.

The work being carried out by Angus Council and their many enthusiastic partners is evidence of how working in partnership and adopting good practices can embrace improvements for species and habitats. What you might call deploying a blizzard of great nature-friendly activity in the east.