All Rhodies lead to Galloway

I was delighted today to learn I've been awarded a contract to carry out a survey for the non-native invasive shrub Rhododendron ponticum at several sites in Galloway. In England, ponticum is listed in Part II Schedule 9 of the Wildlife and Countryside Act 1981 (and amendments) which makes it an offence to plant or allow it to grow in the wild, and landowners have a duty to remove it if it occurs on their property. The situation is different in Scotland. Ponticum is listed in the Scottish Biodiversity Strategy’s Species Action Framework (SAF) as an invasive non-native species that presents a great risk to biodiversity – but it is not a Schedule 9 species north of the border and there's no compulsion on landowners to act.

Nevertheless, responsible land owners appreciate they have a duty of care to the environment. Ponticum is widespread and abundant in woodlands throughout Scotland, where it has led to a serious decline in the abundance and diversity of the associated native plant communities. It spreads rapidly and regenerates from small fragments of material. It is poisonous to livestock and cannot be controlled by grazing. It is host to the disease organisms Phytophthora ramorum and P. kernoviae, which attack oak and beech. In 2011, hundreds of Japanese larch trees had to be felled at a forestry plantation on the Craignish peninsula, Argyll, after being found with the deadly Ramorum infection – the first recorded time in Scotland the disease has been found outwith tree nurseries.

I've done a bit of work on invasive species in Argyll and Bute – and they really have an issue with ponticum there. A study by Forest Research concluded that Rhododendron occupies an area of 4,654 ha in Argyll and Bute (in 2008) of which 85% is located within woodland. Control is being undertaken at only 15% of the area affected and the species could spread by half as much again in 50 years.

The SAF states that it is essential that control is coordinated across ownership and administrative boundaries and that follow-up action is sustained to prevent recolonisation of cleared ground. Although it is difficult to control, there are management options available. Glyphosate is the usual control agent – although I anticipate that could be problematic to use in the water-rich environment I'll be studying in Galloway. Nevertheless, I am looking forward to visiting one of my favourite areas in Scotland in coming months.

Reference: Edwards, C. and Taylor, S. L. (2008). A survey and appraisal of Rhododendron invasion in Argyll and Bute. Forest Research. Reports and a presentation on best-practice control of ponticum, can be found at: http://www.forestresearch.gov.uk/fr/INFD-7DYGEN

Barscube Butterflies

This is my local patch – Barscube Hill in Renfrewshire. It guards the south bank of the River Clyde just west of the Erskine Bridge and, although it's high ground doesn't even scrape 100m, it stands out as an obvious high ground feature for miles around. The hill is conveniently split into an east and west side, with obvious differences in habitat character.

On its higher, east flanks, the upland acid-grasslands are heavily grazed by sheep in summer and cattle in winter. On the exposed slopes, the only shrub cover are a few gnarled hawthorns and patches of gorse and broom which fill the stream gorges and hollows. A trig point is located at NS 38893 71525 and offers very grand 360 degree views for such a modest peak. The shot (above) is looking NE just an hour before dusk as the light plays on the Kilpatrick Hills. A glance west would take in the Clyde Estuary, while Ben Lomond and the Arrochar Alps is to your north and the Renfrewshire Heights spread away to the south. Well worth the effort to make the short climb.

The west side of the hill has a much more diverse habitat. It is not grazed by livestock and features moorland and upland heath, with blaeberry and a rich array of acid-loving grasses and flowering plants. Nothing botanically earth-shattering, mind, but a nice spread all the same. There's substantial Rowan on the lower slopes and in isolated patches on the moor itself, a couple of patches of conifers and a fantastic upland pond. It's a great place to explore and it has some decent wildlife.

Since it's rather a dismal day today, I'll brighten things up by looking this time at the butterflies of Barscube Hill.

The hill is notable for its healthy population of Small Pearl-bordered Fritillary, which appear in mid May. Most marshy ground at Barscube has a few, congregating on Marsh Thistle and Marsh Cinquefoil and basking in the rushes. My best day count was more than 100 individuals so my patch is quite important in a regional context for this UK BAP species. It's certainly one of my favourites.

Small Heath is the other UK BAP species, a grassland species that I find notoriously hard to snap! The last two summers have been pretty dismal for this little butterfly, with numbers down 50% and 60% respectively on numbers in 2011 and 2010.

Small Copper is another fairly abundant species, although its numbers really swing from year to year – 2012 was one of my worst on record during my butterfly transects here. This one's nectaring at Sneezewort, but they are commonly associated with Ragworts. I sometimes find the caeruleopunctata form, with blue spots on the hindwing – a very special species.

Green Hairstreak is a Renfrewhire BAP species and has a foothold among the Blaeberry and Gorse, its larval plants, at Barscube. It's hard to spot and never numerous – it's small colonies usually number just a handful on any visit – but it is always a delight to find. An early-flying species, you know when you see the green marvel, that spring is on it's way.

We didn't have Ringlets at Barscube Hill until five summers ago, when the first ones and twos appeared at several grassland sites. Numbers have grown quickly and it is now more common than Meadow Brown, which has always been here. Ringlets have done well despite the last two cold wet summers and it seems comfortable flying even in overcast, cooler conditions when most other butterflies have gone to roost. I've even seen these in flight if disturbed at night.

Meadow Browns don't seem to have been affected by the arrival of Ringlets, even though they occupy a similar grassland niche. It's not uncommon to see hundreds of these on a warm, still sunny July day. There are a number of other common species including Large White and Small White (usually on the lower-altitude slopes of Gleddoch); Peacock and Small Tortoiseshell are more common in late summer and autumn when they visit knapweeds and creeping thistles.

Painted Lady is an irruptive species and was last seen in numbers during the big migration year of 2010, when there were several score at Barscube Hill. This was part of a big invasion in to the UK from North Africa involving millions of individuals. Visible migration is normally a term associated with birds, but I remember sitting near the trig point in late May, counting these strong fliers as they beat their way along the high ground then disappeared north over the Clyde Estuary. Later, there were dozens refuelling at Ragworth, Knapweed and Devil's-bit Scabious in autumn. Typically, I've haven't recorded a single Painted Lady in Renfrewshire in either 2011 or 2012.

Finally, Green-veined White is the most abundant and widespread species on my local patch. I think these are great value butterflies, and the intricate patterning on their hind wings makes them a very nice macro subject. So roll on the spring – and those Green Hairstreaks taking flight again.

A ray of October sunshine

Melangyna umbellatarum01, a photo by eastendswift on Flickr.

You can't beat a sunny day in October – and although it never got much warmer than 12ºC today, it convinced a host of hoverflies that summer was not yet over. Indeed it proved something of a red-letter day when a trip to Finlaystone Point, Renfrewshire, was rewarded with this cracking female Melangyna umbellatarum.

This is a new species for me and apparently the first record for Renfrewshire/Inverclyde VC, based on the new hoverfly atlas. It's a scarce species in the north and late in the season – so one I'm well chuffed with. Also present were good numbers of Eristalis tenax for the site, a late Syritta pipiens and five other Syrphids. Six Small Tortoiseshells and a Peacock were nice to see, as were three Greenshanks.

Welcome to my Blog!

clyde sunset08, a photo by eastendswift (looking for a job) on Flickr.

This is the first post to my Blue Leaf Nature News blog so I thought I'd set out what people can expect to see.

In the coming weeks and months, I intend sharing news about the activities of Blue Leaf Nature and many of my wildlife experiences when I'm out and about with my camera.

For the past four years I have carried out biodiversity monitoring for one of my corporate clients in Argyll – so I'll look at posting a review of some of the highlights. Located around Loch Awe, the site has proven a great area for birds, butterflies and other insects.

You will see from my profile that I'm very interested in invertebrates, particularly hoverflies – so I'll be compiling a review of the year. Despite the cold, wet spring and summer, I've had a great year and recorded several hoverfly species that are new to the Renfrewshire/Inverclyde vice county.

We are at the tail end of the season now, though, with the nights drawing in and the temperature starting to dip. This is around the time of year I turn my attention to landscape photography – so I'll kick start this blog with one of my recent shots, a sunset taken at Woodhall on the River Clyde just along the road from where I stay.

This is one of my favourite photography locations, so easily accessible and with great views west towards the Clyde Estuary. The wooden posts are the remains of timber ponds, where the shipbuilding industry in the 19th Century seasoned wood for making the ships that made the Clyde so famous. The posts add great foreground interest for the amazing, blazing sky – the sign of a cold front moving in.