Mixed ground-feeding flock at Roughdown

Throughout the winter, there is often a lovely mix of bird species feeding out in the open on Further Roughdown. One morning in October, I had Chaffinch, Green Woodpecker, Redwing and Mistle Thrush all feeding within one square metre. Today, a colourful flock of Greenfinches had joined the throng. For the full count, click HERE.

Warm enough?!

Meadow Buttercups flowering on Bulbourne Meadow 18th December 2015

I thought it was worth just noting the extraordinary weather we’ve had so far this December. On Saturday, temperatures reached 16°C at Northolt (the nearest observation site to Hemel). My car thermometer read 15°C. Mistle Thrush, Song Thrush and Great Tits have started their Spring songs. Robins and Wrens are singing (but do most of the year). Meadow Buttercups are flowering on Bulbourne Meadow and over at the Brickworks today, I came across leaf burst on Hawthorn (which shouldn’t happen for at least another couple of months!). It’s all rather worrying. If we’re going to get very cold weather this winter, it needs to happen asap before plants and flowers are too far along their springtime processes to recover. We’ll just have to watch and wait, I guess.

This will be my last post before 25th, so, I shall wish you all a very happy Christmas. Take care!

Lesser Redpolls at the Brickworks

Lesser Redpoll is not an easy species to see around Hemel Hempstead and, up until today, I'd not seen them at Bovingdon Brickworks either. For more on the sighting see HERE.

Mystery burrows at the Brickworks

David K had come across two curious burrows at the Brickworks a few weeks back. Thanks to the use of night time camera traps, we've solved the mystery, HERE.

The Small Blue Project

The Small Blue: what is it and what does it need?

The Small Blue (Cupido minimus) is the UK’s smallest resident butterfly. Its survival is entirely dependent upon the presence of Kidney Vetch (Anthyllis vulneraria), a plant which can only flourish in early successional conditions (i.e. short-turf grassland with abundant bare ground). Whilst the larvae need the Kidney Vetch, the adult butterflies need places to perch and to roost. Ideal habitats include chalk & limestone grassland, especially with naturally occurring broken ground; man-made habitats such as quarries, gravel pits, road embankments, disused railways and other brownfield sites as well as coastal grassland and dunes.

UK decline and status in Hertfordshire

Across the UK, it’s estimated we’ve lost 80% of our chalk grassland habitat over the last 60 years. That's 80% of the sites where Kidney Vetch has the potential to flourish. And, according to Butterfly Conservation, we’ve lost nearly 40% of the UK’s Small Blue butterfly population since 1970. At the end of 2014, there were only 3 known colonies of Small Blues in the whole of Hertfordshire. It’s rare and is a high priority UK Biodiversity Action Plan species.

10/06/2015 Small Blue on Kidney Vetch at the A41 Bourne End exit

Hemel Hempstead 2015

On the 8th June 2015, David Kirk and I happened to spot a single Small Blue butterfly in Dellfield meadow, Westbrook Hay. We could hardly believe our eyes! It was the first to be recorded on Trust land. Further investigations revealed that the roadside verge of the A41, less than 200 metres away, had been planted with Kidney Vetch (KV). Two days later, I counted up to 12 Small Blue butterflies on KV beside the A41 at the Boxmoor/ Bourne End exit.

Eager to confirm breeding, over the next 9 weeks, I visited the A41 site at least once a week. By the middle of July, larvae were appearing on the KV flower heads and at the very end of July, a second, albeit modest generation emerged of at least 3 butterflies. It was the best possible news. And, the Trust, who'd been keeping a close eye on progress, and had already been considering the feasibility of attracting Small Blues to the land, were keen to do everything in their power to help sustain this rare, local breeding population.

Small Blue: larvae through to adult at the A41 colony

The Box Moor Trust Small Blue Project

The KV along the A41 isn't managed or protected. The Trust’s aim is to attract the butterfly to food plants within managed habitat so that the colony is safeguarded. A handful of suitable sites nearby, on Trust land, were identified for an autumn planting of Kidney Vetch: 2 at Roughdown Common (chalk grassland) and a few at Bovingdon Brickworks (a brownfield site with areas of nutrient poor, bare sandy, clay soil). The Trust worked extremely hard to dovetail this project with county-level conservation objectives and researched thoroughly the various conditions needed to ensure that both Kidney Vetch and Small Blues would be given the best chance to thrive. At the end of November / beginning of December, organised and led by David Kirk (Chairman), more than half a dozen enthusiastic helpers (from trustees, staff and volunteers) rolled up their sleeves and planted some 500 seedling plugs and seeds across the two sites.

27/11/2015 Kidney Vetch plants (plugs & seed) protected from rabbits by wire mesh
Left: Lower Roughdown south-facing bank by A41. Right: Further Roughdown sheltered gully by railway line

04/12/2015 Kidney Vetch plants (plugs) protected from rabbits by wire mesh
South-facing bare-soil banks at Bovingdon Brickworks

04/12/2015 Left: a south-facing bare soil bank was sown with Kidney Vetch seeds. Right: more KV plugs protected by wire mesh
Bovingdon Brickworks

David (Chairman), Peter Ablett (Chairman of Estate & Land Committee) and other key trustees, volunteers and staff have busted a gut to get this project off the ground before winter. Let's hope the rabbits and slugs munch elsewhere and we reap the well deserved rewards in the spring!

Siskins on Blackbirds Moor

Siskins are resident in the north and west of the UK but, here in Hertfordshire, we have to wait until the winter to spot them. Smart, yellow and black and streaky, these small-billed finches favour the seeds of Alder cones during winter. For the past 3 years, I have been keeping my eyes peeled for them around Trust land but it wasn’t until this autumn that I first saw and heard them on passage migration. The great news is that a small flock are currently feeding in the Alders beside the canal on Blackbirds Moor. They’re best viewed from the canal path with binoculars, from the opposite bank. If you have no luck there, the birds are also occasionally visiting the Alders on Hardings Moor. They'll stay as long as there's food and then they'll be off somewhere new...

Keep your ears open for their whistling calls.

Little Egrets hit double figures

The wet weather continued into Saturday and so did the 7 Little Egrets on the Hemel moors. More importantly, 7 became 8 and we hit double figures, TEN(!), for the total number of individuals visiting the Bulbourne in the last couple of months.

For a brief spell, the rain stopped and the sun came out. 5 Little Egrets on Bulbourne Meadow, 7/11/2015

Yesterday, 5 birds had gathered on Bulbourne Meadow and 3 were hanging out on Fishery Moor. Amongst them were the same 2 colour-ringed individuals as the previous day. That meant, we’d gained another un-ringed bird, probably attracted to the site by the large gathering. It was also interesting to note that 3 immature Grey Herons were also on Bulbourne Meadow and at least 1 other immature bird, probably 2 more, were further upstream. The most I'd seen on previous visits were 2 immature birds.

So, we’ve had 6 un-ringed and 4 ringed Little Egrets frequent the moors in the last 9 weeks. That’s pretty good going for an area which experiences frequent disturbance from pedestrians, runners, dogs, etc.