On the road to better times

Road verges have been in the news of late. There is a growing realisation that these areas, if managed sympathetically for nature, can be places where wildflowers and wildlife can flourish, and high on the list of potential beneficiaries are pollinators.

Much of what you may have read or seen will doubtless have been centred on England. There has been widespread coverage of actions in the likes of Rotherham, Newcastle and Sheffield across the media. And much of this is down to the energy of Plantlife who had been campaigning determinedly to make the most of our verges.

Now there are good news stories emerging in Scotland too.

Take the Aberdeen Western Peripheral Route/Balmedie to Tipperty project for example. This 36 mile route provides a much-needed bypass around Aberdeen, and was one of the biggest construction projects seen in Scotland. Given the scale of the project, there were inevitably some challenges, but in equal measure it offered opportunities.

The funding partnership of Transport Scotland, Aberdeen City Council and Aberdeenshire Council set a fine example from the off. They have overseen the project around Aberdeen which was procured as a Design Build Finance and Operation (DBFO) scheme using a joint venture partnership of contractors.  The consultants managing the scheme on Transport Scotland’s behalf were Jacobs.

The work in the north east followed what is now Transport Scotland’s favoured model. This requires the use of native plant species, of local provenance, in all works on Scotland’s trunk road network. It’s an approach which has been championed for the past two decades, and the majority of new works now include significant areas of wildflower seeding as an integral part of project plans.

You can see the benefits of this approach clearly around Aberdeen.

At Derbeth Overbridge, which carries a new access road over the bypass, there are large numbers of ox-eye daisies and white clover on the embankments and cuttings. For hard pressed pollinators clovers and oxeye daisies are a most welcome addition to their resources, and both were firmly part of the planning here.

The Balmedie to Tipperty dualling section of the A90 attracted lots of favourable comments as the verges were looking spectacularly colourful earlier this summer with great swathes of poppies and sea mayweed. The area around the Balmedie junction was a particular highlight.

In isolation these sites are good, viewed as part of a larger picture they are great. As one of my good friends in Aberdeen said recently “The great thing about roads is that they are all connected, so they have huge potential to be a valuable part of a pollinator habitat network.”

Not far from Derbeth Overbridge is a sizable patch of kidney vetch. A coloniser of poor, bare soil it is a great source of nectar and pollen for bees and hoverflies. It is one thing for good food sources to emerge, it is quite another for them to avoid the mowing machines. But here too the news is good. Mowing seems to be confined to a narrow strip adjacent to the kerbside and around signs and such like. As a result things like white clover are abundant along the bypass verges and this relaxed and complementary  mowing regime is certainly paying dividends for pollinating insects.

Few projects are perfect and there is – as Glen Campbell sang in Rhinestone Cowboy – compromising to be done.  But even so there is a lot of a positive nature that the Aberdeen bypass can reflect on.

In the course of any construction project there is a balance to be struck which we measure in terms of net biodiversity gain or loss. But this project certainly tried to ensure the balance was on the positive side.

The installation of wildlife bridges at Kingcausie and Kirkhill was a first for a Scottish trunk road and is a sign that the need to provide safe crossings for wildlife (and thereby join habitats) is rising up the agenda quickly. You may have seen this on the continent, now it is making inroads on our own shores.

Transport Scotland has had this kind of positive outcome in their sights for some time now. Over a period of time, successive schemes combined with a verge management policy that actively encourages the development of species rich grass swards have taken centre stage.

Through the introduction of mowing regimes that minimise cutting in areas where there are no operational or safety issues, you can begin to see a noticeable increase in the flora content of our road verges.

Arguably this has been particularly evident this year – perhaps partly related to optimum weather conditions – with many roads around the Scottish network displaying abundant displays of wildflowers, native grasses and other desirable ground cover species.

You can always build on success.  Hence the high profile and ongoing A9 Dualling Programme has seen Transport Scotland aim to establish a Supply Contract for all the native seeding requirements across the whole series of schemes using local origin collections.

But let’s dwell on success and return to Aberdeen.  Relaxed mowing regimes, abundant food sources, connectivity … little wonder the Aberdeen bypass is catching positive headlines, and pollinators are amongst the creatures clearly benefitting.

 

READ MORE …

You can find out more about Transport Scotland’s approach to verge management in their excellent landscape policy document, Fitting Landscapes.  Transport Scotland recently supported PlantLife in the preparation of their soon to be published best-practice guidance on good management of road verges .

 

Images 1 and 3 courtesy and copyright Michalina Wojcik of Jacobs, Images 4 and 5 courtesy of Angus Corby of Transport Scotland.

Life, but not as they knew it

Dead lions, dandelions, treacle, pollen & cesspools – the many facets of the drone fly’s life By Athayde Tonhasca

Tis seldom when the bee doth leave her comb, in the dead carrion.

Henry IV, William Shakespeare

If you take a close look at a tin of Lyle’s Golden Syrup, you will notice something peculiar: the image of a dead lion surrounded by a swarm of bees, and underneath the slogan ‘Out of the strong came forth sweetness’. The image is based on the Biblical tale in which Samson kills a lion, and later finds a honeycomb inside it. This supposedly inspired Samson to write a riddle: ‘Out of the eater came forth meat and out of the strong came forth sweetness’. Apparently the story impressed Scottish businessman Abram Lyle, and so one of Britain’s oldest brands was born; its logo remains virtually unchanged since 1885.

Lyle’s Golden Syrup. © Wikipedia Creative Commons.

The biblical quotation appealed to Victorian virtues, but the yarn about dead animals and bees is more than 2,000 years old: the Greeks and Romans believed that honey bees originated by spontaneous generation from oxen carcasses. The story inspired the poet Virgil around 29 BC: ‘from putrid gore of cattle slain/bees have been bred’. It also inspired Shakespeare.

The classical and biblical bees-from-carrion tale would be seen as just another myth from ancient peoples who didn’t know better if it wasn’t for the Russian diplomat and entomologist Baron Karl-Robert von Osten-Sacken. In 1893, the Baron suggested that ‘bees’ found around dead animals were in fact flies: not the expected blow flies and bluebottles, but the drone fly, Eristalis tenax.

The drone fly (a species of hoverfly) is native to Europe and one of the most common British hoverflies. In some years populations are boosted dramatically by immigration from the continent.  The name ‘drone fly’ comes from its resemblance, in appearance and behaviour, to honey bees. Males are territorial, chasing away other males and even bees, wasps and butterflies. The adults feed on pollen, especially from yellow flowers, and they are believed to contribute to the pollination of wild plants and some crops.

A male drone fly. Like many fly species, males have larger eyes that almost touch, while female eyes are spaced apart. © Wikipedia Creative Commons.

After mating, females lay eggs near dirty, contaminated water such as manure lagoons, holding pits in livestock areas, ditches and wet silage. The larva has a long ‘tail’, which is a specialized respiratory structure that works as a snorkel, allowing the insect to breathe air from the surface. This respiratory appendage gives the larva its common name: the rat-tailed maggot.

A drone fly larva (rat-tailed maggot). © Wikipedia Creative Commons.

Baron von Osten-Sacken has shown that under the right circumstances, female drone flies lay their eggs in water accumulated on or around animal carcasses. As these flies look, buzz and fly just like bees, it is easy to understand how they were mistaken for honey bees emerging from dead animals. Hence another ancient myth was created.

 

To learn more about the drone fly, go to

University of Florida’s Featured Creatures page.

Steven Falk’s Flickr album.

A walk on the wild side

Take a walk around Taynish NNR at this time of year and you’ll be in for a treat. Situated in the area of Argyll and Bute, it’s a flurry of flowers blooming and insects buzzing. Caroline Anderson, on the back of a recent visit, provides an insight on the insect comings and goings on the reserve.

7:15 a.m. and already 18°, the sun bursting through the trees bodes well for this visit to the pollinator trail.

Lots of new growth around, the wild roses are blooming, there are new leaves on the oak trees and the cotton-grass glows in the early light.   As I walk along the boardwalk the damsels are already flitting about in the warmth, the darters, however, are still warming their wings – which is great for me!

Further down the track in the burn next to the mill the hemlock water dropwort, which for humans is the most poisonous plant in Britain, is completely alive with pollinator insects.  Some of them wear the pollen like sequins and it glistens in the sun.

Down by the shore the butterflies are starting to wake up and the first of the day is a red admiral, enjoying the sun on its wings.  On the shore on a clump of nettles, there are lots of peacock caterpillars jostling for what’s left of the leaves. Back up the track and the speckled wood butterflies are on the wing, occasionally stopping for sustenance.

Whether one of the smallest  or one of the largest  insects they are all busily keeping our plants and trees pollinated which makes our countryside so beautiful.

The imperfectly perfect impersonator

Insects face many struggles to survive: finding food and shelter, enduring bad weather, avoiding diseases. And, of course, doing their best to not become a meal for one of the many predators lurking out there.  In today’s blog, Athayde Tonhasca looks at impersonation as a survival strategy.

Some insects escape predation by camouflage, the ability to blend in with the surroundings and not be seen. Others fool predators into thinking they are part of the landscape by looking like leaves, twigs or other structures. This evolutionary adaptation is known as mimicry: stick insects are good examples of species that rely on this trick.

Some insects rely on a different ruse: they evolved to look like dangerous creatures, an adaptation known as Batesian mimicry (first described by the English explorer-naturalist Henry Walter Bates). By resembling a species that is harmful, being poisonous or aggressive, the non-harmful insect is less likely to be attacked by a predator.

The hoverfly Criorhina floccosa is a good example of a Batesian mimic; by resembling the common carder bumblebee (Bombus pascuorum), the fly can go about its business in peace, as predators will not risk being stung by what looks like a bee.

This hoverfly can be seen in Scottish woodlands, basking on sunlit foliage and feeding on hawthorn, rowan, brambles and rose flowers. Just like the hoverfly in the photo, these flies often forage along bumblebees. The larvae develop in decaying wood of mature broadleaved trees such as oak and beech.

The hoverfly Criorhina floccosa ©Athayde Tonhasca

The common carder bumblebee Bombus pascuorum ©Creative Commons

You might say that it can’t be difficult for a bird or other predator to tell both species apart; the hoverfly is clearly different from the bumblebee. However, Swedish biologists have evidence to suggest that predators rely on rudimentary signs to identify their prey, such as colours, patterns or shapes. If an insect is able to mimic the few factors a predator has an eye for to distinguish between edible and inedible prey, the deception is effective; there is no need for a perfect match. This would explain why there are so many cases of crude mimicry in nature: there is no evolutionary incentive for a better disguise.

Hoverflies are some of the most frequent flower visitors in a range of habitat types. Although they do not receive the same attention as bees, hoverflies are becoming increasingly recognised as important pollinators for some crops, and especially for wild plants in higher altitudes and latitudes.