Blue Butterflies and why they are not so common

It is noticeable that the Common Blue is rare locally, yet Birds Foot Trefoil the food plant for the caterpillar is, if not common, certainly widespread. But the following story suggests why this might be so and also suggests that in the natural world the answers may often be less obvious and more complicated than you might think.

The Large Blue butterfly went extinct in southern England due to the price of wool and myxamatosis. The LB lays its eggs on Wild Thyme, but after feeding up the caterpillar seeks out the nest of a specific species of ant and using pheromones convinces the ants into taking it in (well usually !). The caterpillar thanks it`s host by predating the ant lava and suitably fattened turns into a chrysalis. Emerging from the transformation the LB emerges in all it`s splendour (the largest of the Blues) and leaves the nest to start the cycle again.

But here`s the problem, reduction in sheep and rabbits in areas of the South Downs led to the grass getting longer. Not a problem for the LB, or the Wild Thyme, but for the specific ant species the slight cooling of the ground temperature caused that species of ant to abandon the hillsides. They still colonized the heavily grazed fields in the valleys, but Wild Thyme did not. So the chain was broken and the LB declined and went extinct in Britain, subsequently re introduced and surviving on specifically managed sites.

So the Large Blue had a breeding cycle that depended on two other species living close by, but the overlap of their habitat requirements was at best marginal, neither species needed the other and as the LB predated both of them it`s absence could be seen as a bonus. So the low numbers of Common Blue my well be a product of it`s specialist life cycle – it can only successfully breed if Birds Foot Trefoil and a specific species of ant are both present in the same location.

 

Speak up for Wildlife Friendly Road Verges

Road verges form a significant wildlife resource in Rushcliffe. They provide interconnectivity for a wide variety of species  ranging from the wide tall grass and Cow Parsley verges in the south of Rushcliffe or the colourful  daisy and dandelion flower dotted verges elsewhere. They provide food, shelter and support for many different invertebrates, small mammals and birds etc. They can also look good, providing they are not over mown.

However, it is fair to say that not everybody sees it that way: some see leaving verges uncut as untidy or as cost cutting. The point is people do write to councillors to complain, getting their attention. So it is incumbent on fans of flowery, abundant roadsides to also write into councillors praising verges that are looking good, grumbling about verges cut in their prime. Either way you are making the case that road verges matter and making the case for restraining the mowers.

The Highways Agency are responsible for mowing trunk roads, namely A453, A52 and A46 in Rushcliffe. But all other road verges (rural and urban) are the responsibility of Notts County Council. The standard NCC regime is a one metre wide cut along the road edge twice per year (wider on bends and junctions). There is a full width verge cut once every three years, carried out on rotation. Overall this is not bad and reasonably in line with Plantlife guidance on a mowing regime that is a compromise between wildlife and road management.

But whilst it is County Councillors who can most influence mowing policy, Rushcliffe Councillors will also get adverse comments about verges and discus them with their county counterparts, so we would advocate contacting both your Borough Councillor and County Councilor, speaking up for road verges. In addition you can raise the issue on social media particularly by commenting on Council Facebook pages etc.

Whether you are pleased with how verges look, or feel Councils could do better. please stand up and be counted for wildlife friendly road verges.

We have produced some sample words that you might like to use in your communications, which can be found on Road Verge Letter

Gordon Dyne on behalf of South Notts Local Group (NWT) and Rushcliffe Nature Conservation Strategy Implementation Group

Sharphill Wood Work Party

Our next work party at Sharphill Wood will be on Sunday 27th June. We hope to see you there, but please let us know beforehand if possible.
Please make sure you read the detailed information on Covid-19 precautions at the end of this invitation.
When: Sunday 27th June, meeting at 09.45 until about lunch time.
Who: No experience necessary and there’s always something to do even if you can’t do heavy work.
Where: Meeting point will be the entrance from Peveril Drive, 09.45, or find us in the woods if you arrive later.
What: We will be doing more work on path edging and trimming encroaching vegetation along the paths using scythes. Relevant training will be given where necessary.
Safety: All volunteers must pay attention to the safety of themselves and others. A Risk Assessment will be prepared and will be available for inspection on the day. Please respect all decisions of the work party leader.
Other Useful Info:
· Please wear suitable gardening clothes and sturdy footwear. Covering arms and legs might be advisable to help avoid insect bites, ticks, stings, scratches, etc.. Also the use of insect repellent might be appropriate, particularly from spring through to early autumn. Bring gardening gloves and other items listed under Covid-19 precautions at the end of this email.
· To minimise sharing of tools, we ask people to bring their own where possible. On this occasion a lopper may be useful but is not essential.
· Bring a drink. We will stop for a break mid-morning.
· Waterproofs / sun-cream would be useful to cover every weather eventuality!
· It is highly recommended that you ensure your tetanus vaccinations are up-to-date.
Please advise the leader of any pre-existing condition that should be taken into account in the event of a medical emergency during the work party.
Contact john.r.elwell@outlook.com

Road Verge Managment

The grass cutting regime for road verges is quite a controversial topic, for some it is not enough, but within the nature conservation movement it can be a source of quite despair when a verge is mown at the height of the flowering season – not jut the loss of the picturesque, but the loss of potential seeds and food sources for insects, birds and mammals.
Here is our understanding of how verge management is split up and what are the current mowing policies in the Rushcliffe area
 
Highways England Verge Management on Trunk Roads (A453, A52, A46)
 
• Visibility zones = 3 times pa
• Amenity areas = 8 times pa
• Swathe, Signs, lamp columns and wildflower and open grassland = annually
 
County Council Verge Management (all other A Roads + B and minor roads)
 
Rural verges have a one metre cut along the road edge twice per year (wider on bends and junctions), with a full width cut once every three years on a rotation.
 
Urban verges are cut five times per annum, although we do know of at least one verge were NCC have agreed to just do a visibility cut for the first two cuts to allow the wildflowers to seed.
 
Parish councils sometimes take responsibility for verges in villages.
 
On occasions house owners/landowners choose to mow verges in front of their property, hence you may see random intensively mown stretches of verge.

Wilford Fields

A few days ago went along to have a look at Wilford Fields (behind ROKO on Wilford Lane), it`s the big green “hillock” surrounded by Housing. And it was a pleasant oasis, and dog walkers aside, you would hardly know you were in an urban area. A good basic wildlife site, I identified some 30 species of wildflower during a walk round, across and generally all over.
 
Not a bad haul nothing really out of the normal, but a good number of the usual suspects. And this is important because it means that the insects that exploit the usual suspects (food, eggs etc) are also likely to be around. If the foodplant is common, then it is likely so is the predator.
 
And this brings me to the subject of grasses – I reckon there were at least 10 species of grass on site and grass is the principal component of grassland (go figure !). Consequently you will find an awful lot of insects use grass (or more likely specific species as both a foodplant and an egglaying plant – it makes sense, exploit the most common foodstuffs. You only have to look at British moths to realize that many of them do exactly that.
 
So in summary a good, useful wildlife site.
 
PS I found White Campion and Goatsbeard neither of which are common in these parts, I think.

Wilwell Southern Marsh Orchids

Counted the Southern Marsh Orchids at Wilwell, a cracking 713 (approx), the vast majority being in the middle & southern lower meadow. This is way up on last years worst ever count of just 38. A remarkable turn round even for a notoriously variable plant like SMO.
 
It has been suggested that as SMO survive as bulbs and the bulbs are able to split in two, this might explain these rapid changes, but not why. Many of the flowers were just coming into bloom so I think I caught them at peak SMO. But the flowers are very variable with some fine flower spikes, but in other cases very stunted.
 
Such little clusters of SMO`s are quiet typical of the lower meadow colony, with other plants skulking in the vegetation.
 
But the other interesting thing was, they have reappeared in the marsh area below the seat, not seen for maybe 15+ years. This is in direct contradiction of my claim that you don`t find SMO`s in really wet areas, there was a one inch layer of water across the area. Ornery little critters !
Also worth saying that at 205 flower spikes (again approx) this was the highest Green Wing Orchid count since the “great flood” decimated numbers in 2012/13.
The last couple of years has also seen the reappearance of Twayblade orchids in two (very) little populations. The original population was also lost in the great deluge, so in fairness at least one population well to the south might have always been there a green  plant hidden in the vegetation.