Friday, 8 April 2011

A busy wildlife week

Spring is always like this. We go through winter longing for something different to happen each week, then spring arrives and it's 0 to 100mph in a few days. New species coming in as migrants, everything is emerging faster than it can be counted and this week as many of you bloggers also know, soft southerly winds have made the days feel like summer, at last.

I have been all over the place for work and pleasure, so a busy time, but never too busy not to be thinking about a blog posting or two. So herewith a short synopsis of the wildlife this week (Even Milton Keynes on Monday produced a few birds on the journey, red kite was good - but that's the last I'll mention that town here).

This morning, after a well earned farmhouse breakfast at Cobb's Farm Shop near Hungerford, I headed off to Wiltshire Wildlife Trust's Ham Hill.

This is a small linear reserve on the Berkshire / Hampshire / Wiltshire border. I'd read about it a while back and one evening a week or so back located it. Its main attraction is that it is a Saxon sunken walkway through chalk downland. Absolutely fascinating to think people have walked this way since Saxon times.

The site is well known for orchids later in the season, including the rare musk orchid and the Duke of Burgundy butterfly. It isn't too bad in early April. I watched a male and female blackcap singing their wonderfully melodious song, other passerines were about and on the downland next to the scrub skylarks serenaded newly arrived swallows.

Not bad views either back towards Wilton and Marlborough

Quite a few plants were on the move in the warmer weather including this unusual Moschatel (Adoxa moschatellina). Nothing else looks like this, as when in flower, there are 4 tiny flowers in a square and a fifth on top.

Quite a few cowslips and violets in flower too, although the latter were starting to turn. Sadly I didn't seen any Duke of Burgundy caterpillars feeding on this host plant. I'll make sure though to return soon and attempt to see the butterfly itself.

At a separate location in Wiltshire I came across a Raven nest this week. I'll not say exactly where it is, but I was sitting in the car planning to leave another area of chalk downland when the familiar cronk of a raven alerted me to its presence, then the calls changed and I realised it was the male call as it came in to the female on the nest. This nest was on a clump of Scots pine and with a bit of searching through the binoculars I found the nest (the dark mass in the middle of this photo)

The male spent a lot of time flying between this clump of Scots pine and another about 300 meters away.........

..........from where on the latter tree he set up a continuous cronking (can you see him on the tree below?), probably because I was there, so after a few minutes I made my retreat to leave them to it and then watched them for a while longer from within the car.

Earlier this week I was in Devon looking for oil beetles. And what a glorious day it was too. There is something fantastic about standing on a Devonian cliff and watching swallows fly in over the sea and over one's head. They must have got a shock seeing me as their first piece of England at the end of their migration. But I was happy. It was so special to witness their arrival, as well as painted ladies as they came in over the English Channel on a soft warm breeze.

Back to the oil beetles. We'd set ourselves a task of seeing all 4 oil beetle species in the UK in a day, the black, violet, short necked and rugged. The short necked is very rare and indeed only found in one location on mainland Britain. And the rugged is unlike the other 3 in that it is an adult in the winter between October and late March, but we thought we'd give it a go. However I was optimistic as with me was one of the UK's best field biologist, John Walters who is studying the ecology of these beetles for Buglife.

We began in unimproved meadows near Dartmoor, where almost immediately we saw a male violet oil beetle (poor photo from my blackberry) - males have kinked antennae, though not 100% diagnostic. The host plant of these is celandine where the complicated life cycle involving celandine's, solitary mining bees and hitching a lift take place.

In a simplistic way, oil beetles have a very complex life cycle. The emergent female after mating lays thousands of eggs in an underground chamber. These hatch as minute larval clones of the adult. They then climb onto celandine flowers and wait for a passing insect. Any flying insect can be the vector, but only certain solitary mining bees can play host to the next stage of its life cycle. Anyway a flying insect lands on the flower, the larvae climb on board and are carried away.

If the flying insect is a solitary mining bee, they are taken into the bee's burrow where the larvae detach themselves, eat all the eggs of the bee, pupate and then emerge in a few weeks or the next spring, depending on the species. So a true parasitoid. This is a very simplistic synopsis as the life cycle is under researched, so John is learning as he studies them.

Eventually we found a black oil beetle too, which was fabulous as this meant 2 down 2 to go.

John has also been trying to discover the mating of these beetles and to do so has been collecting females and then introducing a male to them in a Tupperware box. All a little bit too voyeuristic really. But it is all legal as he's working on a research site and the beetles come from and are returned to the same area, hopefully to lay eggs successfully. The male in this photo (on right) grabs hold of the female by her antennae (which is why his are kinked so he can get a good hold), they have a tussle and then mate. The photo below was just after mating.

So after that excitement we headed down to the coast where at a secret location we found the short necked oil beetle, which for some reason I didn't photograph. That was three species found, just the rugged to go, which is known to be in this dry stone wall.

We looked and we searched but there wasn't any rugged oil beetles to be seen. Just too late in the year we think. We did however see a lot of common lizards which were taking advantage of the warm spring sunshine. Just goes to show if you stand still long enough, and look long enough, wildlife comes to you.

But the best was left to last. We'd been in the field for 7 hours and just about had enough energy to head back to the car. However John thought he'd seen some violet oil beetles making holes in a pathway last week and wanted to check if any were being used for egg laying. We hunted for about 20 minutes and then lo and behold, a female violet oil beetle was in the actual process of laying eggs. Just her head and one antennae were visible out of the soil, with her body completely buried. Absolutely fantastic to see this happening there and then. A great way to end an fabulous day in Devon.

Sadly not great photos as I still can't get my new Lumix to be pin sharp on the macro setting. I think it needs to be on a tripod. But there she is, egg laying with abandon.


  1. Fabulous photos of what sounds like a glorious week. There's something about weathered walls and old beaten walkways that seems to connect you to the past like nothing else I know, I must try take a wander out to Ham Hill sometime :-)

  2. Lovely photos from Ham Hill (great views)Andrew. Sounds a wonderful place to visit especially with a sunken walkway. Fascinating information about the oil beetles and well done on getting the common lizard photos.