Friday, 11 April 2014

Species galore!

I've had a productive couple of weeks for wildlife-spotting - spring is properly here and the insects in particular are responding to the change.

As the buds burst and flowers begin to appear, insects too are emerging from their winter dormancy. The new leaves are covered with leafhoppers and caterpillars, and the flowers with pollen beetles and bees.
If you go by the media reports you might be forgiven for thinking there's just one British bee, the honeybee Apis mellifera. In fact, it's a bit more complicated than that - we have 1 honeybee, 25(ish) bumblebees and 230-250 species of solitary bees. Various bumbles and the honeybee visit my garden, but I'm lucky enough to have some of the solitaries call it home. In particular two species live in the back wall of my house. One of the signs of early spring is the colony of Hairy-footed flower bees (Anthophora plumipes) waking up, darting at high speed between flowers and zipping in and out of the holes in the wall. Zipping is really the word too - electrifyingly fast, the males in particular seem to move flower to flower without occupying the intervening space.
April 2011 007
A male Hairy-footed flower bee, Anthophora plumipes
The other species hasn't shown itself just yet - the Red mason bee, Osmia bicornis (formerly O. rufa, a much more appropriate name for this bright red bundle of energy!). It's about - I found one in Oxford city centre last week, and several in Winchester cathedral close on Tuesday - but my garden colony are clearly having something of a lie-in!

The best indicator of the changing seasons though is the moth trap in my back garden. A 125-Watt mercury-vapour bulb perched on top of a box of moth bedding (aka egg boxes), it attracts in a sample of the moths flying past, ready to be identified and released the following morning. You never get the same mix of species and individuals twice running, so it's a great way to measure the changing of the seasons.
The moth trap, doing its thing in the back garden
I started trapping for the year in early March, catching small numbers of the early-spring species. Gradually as the year wore on, the numbers got bigger (60 moths of 11 species on the 2nd April the best to date) and the species changed - Orthosia (Quakers and the Hebrew Character) began to dominate, Common Quaker in particular. In the last week what I think of as the 'late spring' species have begun to appear - the furry Muslin moth (Diaphora mendica) and an early Bee moth (Aphomia sociella) - reinforcing that the world is moving forwards, and summer is shimmering on the horizon...

Monday, 24 March 2014

The North

Another expedition this week, venturing further north than I've ever been before - to Wick, Caithness, in the very top right corner of Scotland.  Being mainly from the southwest, I'm always taken aback by the sheer size of Scotland, and even after flying into Inverness there was still a two-hour drive north to get to Wick itself.
My recording footprint, up to the 20/3/2014
The reason for this long-haul trip was, as ever, insect-related, though again it was more concerned with talking about them than spotting them.  My day job is running the Bumblebee Conservation Trust's bumblebee-monitoring schemes (check out www.beewalk.org.uk and http://bit.ly/beewatch to take part!) and I was in town to give an hour's talk about bumblebees, their current decline, and how monitoring them can help, for the Caithness International Science Festival.  Caithness and the Scottish islands are the last remaining refuge of the Great Yellow bumblebee, Bombus distinguendis, and thus are a priority area for BBCT's conservation efforts - hence my invitation to talk.

As it's around six weeks into the bumblebee season at home in Oxfordshire, before I set off I'd been hopeful that there might be the chance of spotting an early queen - unmistakeably huge, yellow and fuzzy, the general effect is like a flying tennis ball.  However, my hopes of seeing the species for the first time ever were quickly dashed as I drove north through heavy rain and snow showers:  despite the 18C temperatures in the south, March is clearly still winter in Scotland!
Pictured: the view a few minutes flight time south of Inverness.  Not pictured: spring, giant furry bumblebees
After a long Saturday of talking and manning the stand, followed by a wander along the seafront in the teeth of the wind, I gradually defrosted my face and fingers and wondered what to do with myself.  I had a couple of hours free on Sunday morning between breakfast and having to leave for Inverness and the long trip south, but clearly there would be no bees: even sheltered spots by the shoreline had only turned up a couple of chilly-looking carabids.
The Whale & Dolphin Conservation Society caused some serious stand envy
The name Wick was ringing a distant bell marked 'rare species', and a quick search revealed the existence of Wick Sedge, Carex recta.  With only three British populations, this unassuming plant was one of Britain's rarest species - and it had a huge population less than a mile from me!  That was Sunday morning sorted...

Sunday dawned bright and clear, but -3C and blowing a gale.  I checked out and headed over to the Lower Wick River SSSI.  I had been expecting a struggle - this was a very rare plant, after all - but as soon as I reached the river, the mudflats were covered in sedge shoots - this must have been the vast single-species stand mentioned in the site description!  Sure enough, the grid references matched and the remains of last year's plants checked out.  I'd utterly failed in my first attempt to find a vanishingly rare bee, but vast numbers of an even rarer plant made a pretty satisfactory substitute!  I walked back to the car, and started the long, long trip south.
Mudflats: Unprepossessing 

Wednesday, 12 March 2014

Oil be back...

A slight diversion this week, and a step back in time to one of my former local patches.  When I first moved to Oxfordshire, in 2008, I lived in Headington, north-east Oxford, and spent a lot of time in Shotover Country Park, then ably managed by Shotover Wildlife.  I now live further away, in south Oxfordshire, but still visit Shotover from time to time to see Black Hairstreaks and other specialities.

Sunday evening was one such time.  On my way home from Savernake forest, as it got dark, I decided to go and see if I could find any Minotaur beetles – nocturnal big, black horned dung beetles found in great profusion on Shotover. 

Well, despite much searching, there were no Minotaurs to be found.  What I did spot, in the light of a fading headtorch, was a great big bulbous black thing - an oil beetle!  There used to be eight species of oil beetle (Meloe sp.) in Britain: three are now presumed extinct, two were thought to be extinct before being rediscovered in south Devon (and now survive in one and two sites respectively), two are widespread, if uncommon, and one is relatively widespread but even less common. 

This one was relatively small, out at night, with a wide (not square) thorax and a groove in the middle of the pronotum – that made it Meloe rugosus, the Rugged oil beetle!  Not only was it a species I’d never seen before, despite looking, but really quite a rare species in Britain with only a handful of Oxfordshire records.  When I got home I checked the records – one previous record from the site, in 1927, and astonishingly, in exactly the same 100x100m square!  After going missing for 87 years, the Rugged oil beetle was back on Shotover… and it had barely moved an inch!

Meloe rugosus - note the distinctive pronotal shape and groove

All the oil beetles share an amazing life-history.  Adult females – like my find – emerge, feed up, mate, and dig a hole in bare ground in sandy soils which they fill with thousands of eggs.  These emerge in spring, tunnelling up to the surface and climbing up onto flowers.  Here the larvae (known as triungulins, after their three-clawed toes) lie in wait for solitary bees.  When a bee arrives, the triungulins grab a hold, and hitchhike their way back to the bee’s nest, where they secrete themselves away in a brood chamber, eating their way through the stored pollen and the bee larvae themselves, before pupating and then emerging the following year, ready to start the process all over again.






Monday, 3 March 2014

Seen through a window

Last week turned out to be more a week for talking about wildlife, rather than spotting it.  A talk on bumblebees at the Cricklade Meadow monitoring conference on Monday was followed by leading an hour's workshop on ladybird identification at the Oxford University Museum of Natural History on Saturday.  Wandering round the museum is always interesting: I'm pretty sure I've never given a talk in a room filled with taxidermied animals and a skeleton before!
Clearly, someone missed lunch
 A later wander round the (excellent) displays did reveal this interestingly-labelled exhibit...
Neither of these moths is actually a Fur beetle
In between giving talks, writing talks, and troubleshooting databases, I did manage to peer out of the window at the bright spring sunshine, and even pop out briefly at lunchtime, in search of movement.

Then, on Wednesday, something happened for the first time this year.  That's right: I had a shave.  But after that, sitting at my desk editing grid references, I spotted another first for the year speed past the window.  Peering out, something dark was buzzing at the bottom of the garden: finally, a bumblebee!  Nipping out, cup of tea in hand, I saw it was a huge queen red-tailed bumblebee, Bombus lapidarius.  After prospecting around the garden wall and my car for a nest site for a couple of minutes she flew away: the first but hopefully far from the last.

While watching the bumble quartering the base of the wall, I noticed something else new.  Several of the comfrey plants were looking distinctly ragged: a closer look revealed dozens (36!) of inch-long, yellow and black hairy caterpillars - Scarlet Tigers!
This is just one of many...
A spectacular big red, black and white moth with a distinctive green sheen, the Scarlet Tiger, Callimorpha dominula, is something of a speciality of the Thames valley and the south-west.  Flying by both day and night in June and July, it's one of my favourite moths - great to see that it's on course for a good year!


Sunday, 23 February 2014

Beetling about in flood debris

Anyone who's not been living under a rock for the past two months can't fail to have noticed that the country is slightly damp at the moment.  Large chunks of Somerset, Oxfordshire, Berkshire and others have been underwater as rivers reclaim their flood plains, while the sheer volume of water has saturated the soil, leaving rainwater pools on the surface.

Of course, floods are horrendous when they affect your property, family or livelihood, but if you're interested in insects and other invertebrates, they can also provide something of a bonanza.  Huge numbers of invertebrates - snails, harvestmen, beetles, and more -  live in the soil, amongst roots, in leaf litter or at the bases of grass tussocks, and at this time of year they're joined by a whole load of extra species that go there to spend the winter.  When the water rises, these invertebrates are flooded out and washed downstream with all the other flotsam and jetsam - litter, sticks, etc.  This all accumulates in heaps of debris around obstructions, and picking through these mounds can turn up all kinds of species.
Flood debris collecting between the bank and a narrowboat
My local river, the Thames, has been flooded to varying degrees since Christmas, and I've been out a few times to see what's been washed up.  The main groups  have been beetles and snails, both terrestrial and freshwater.  Probably the pick of the 27 species of snails that have turned up so far has been the ribbed grass snail, Vallonia costata - a species I'd only ever seen once before, at last year's Bristol bioblitz.  Although it's only 3mm long, the ribbing combined with Mick Jagger lips makes it both distinctive and (for a snail), really rather attractive.
Vallonia costata, photographed down the microscope
Something I hadn't ever seen before was a tiny but very smart harvestman, Nemastoma bimaculatum - black and leggy with two white flashes (hence bi-maculatum).  By far the biggest fraction in the debris  has been beetles, particularly carabids (ground beetles) and staphs (rove beetles), but some smaller stuff has turned up as well.  Some has been impressively small - one that I've yet to do anything with is a featherwing beetle, family Ptiliidae, well under 1mm long!  Because there's so many beetles they're a bit on the back burner until my PhD corrections are finished, but all the other species, plus a bit of judicious lichen-spotting in the back garden, have taken my 1km square list up past 300 for the year - well on track for four figures by year's end!
Nemastoma bimaculatum from flood debris
A still-mysterious featherwing beetle, Ptiliidae sp. Image width approx. 1.5mm!
Flood debris beetles waiting to be identified - mostly carabids, particularly Bembidion spp., but also Heteroceridae, Aphodius, Hydrophilidae, mostly Cercyon spp., and some Chrysomelidae in tribe Alticini

Monday, 17 February 2014

Slightly further afield...

A slightly busy week last week - my PhD viva, two days of a bumblebee meeting in Southampton, and some filthy weather meant I didn't get out into my local patch, other than running to and from the car in the pouring rain.
My local patch, currently.  Not pictured: dry land
Come Sunday though, I'd arranged to brave the floods and meet up with some friends down in Somerset. Despite the non-stop news pictures, most of Somerset is well above the current high-water mark and we all made it to Shapwick in time for for the sun to come out.  After a quick sit-down for coffee and cake, watching small birds on the feeders - Coal tits and Reed buntings new for the year, Collared doves clumsy as ever - we headed down the road to the Hawk and Owl Trust's new reserve at Shapwick Moor
Glastonbury Tor from Shapwick Moor, looking across the grazing pasture and rhynes.
Not many birds about, but some nice snails in the rhyne dredgings, notably the Viviparous snail (Viviparous viviparous) and the Greater ramshorn (Planorbarius corneus), and, in the sandbanks, marine bivalves dating back to the last ice age. A quick lunch stop later, and we were off again, walking down past the route of the Sweet Track, a 2 km wooden walkway built in 3806 BCE and abandoned after less than a decade due to rising water levels, a fate it was suffering all over again with the last month's rain.  It wasn't the only casualty we saw - once ensconced in the hide at the far end of the track, we could see three or four fresh scars in the peat where trees had been blown over that week.

We weren't the only ones to have noticed: a flash of orange and electric blue announced a kingfisher, eagerly prospecting the new earth banks for a nest site.  Overhead a marsh harrier drifted slowly, wheeling effortlessly in the blue sky. As dusk fell, four lapwings flapped lazily by; one of Britain's handful of great white egrets swooped low over the reedbeds; swans slid smoothly across the reflection of the setting sun; several thousand starlings buzzed us, hurtling low overhead with a susurration of wings, as if the reedbed had taken to the skies. Summer's great, but winter has plenty to recommend it if you know what to look for!

Casualties of the storm.  Somewhere in this picture is a kingfisher, but it was a long way away...
Glastonbury Tor, from Shapwick heath
Reedbeds at Shapwick heath
It's important to have all your ducks in a row
Reedmace, Phragmites and ducks
Settling down for the night

Tuesday, 11 February 2014

What's lurking in the Oxfordshire undergrowth?

The prey shifts nervously, raising its head from grazing under the hunter's multifaceted gaze.  Sensing oncoming eight-legged movement, the would-be prey item strikes out with its forked tail, catapulting itself backwards and spinning head-over-heels through the sky as the pincers of the wannabe-predator close on empty air.  This is the seriously weird world of the British microfauna, and it's at least the equal of the charismatic macrofauna you can see on TV.

Pseudoscorpions - the thwarted predator from the scene above - are symptomatic of how this miniature jungle is overlooked.  They look amazingly similar to 'real' scorpions, complete with huge pincers, but lack a sting at the back end.  Although they look far too exotic to be British, in fact we've got at least 27 species and many are quite widespread, particularly in moss, leaf litter, and under bark.  I found this one - Chernes cimicoides - under the bark of a dead Eucalyptus around the corner from my house last weekend.
Chernes cimicoides
Having wandered down to the river Thames to see how high the floods were getting (answer: worryingly high), I spotted that the dead tree had some loose bark and had a bit of a poke around underneath.  These kind of sheltered spots are some of the best places to find insects over the winter, and there were plenty here - woodlice (Porcellio scaber and Androniscus dentiger) scuttled in all directions when exposed to the light, while bean weevils (Bruchus rufimanus) tried the opposite tack and froze, pretending to be lumps of misshapen wood.  Ladybirds (Harlequin Harmonia axyridis and 2-spot Adalia bipunctata) trusted in their defensive chemicals and warning colouration to repel me, sitting in obvious groups, and it was when peering at these (I'm very fond of ladybirds after studying them for four years for my PhD!) that I noticed a 3mm flattened, rounded blob tucked in nearby.  Spotting the pincers I almost jumped for joy - my second ever pseudoscorpion!
Chernes cimicoides in its overwintering cell underneath bark
Reaching 3mm long in Britain and only up to 12mm in the largest species yet found worldwide, these tiny arachnids are close cousins of spiders, harvestmen, scorpions, mites and ticks in Britain, and of whip-scorpions, vinegarroons and camel spiders overseas.  They may not be cute and fluffy but they are amazing to look at, and in their habits - the first I ever saw was in a photo that a friend had sent me to identify a beetle.  When you looked closely, an odd bulge on the antennae was clearly a pseudoscorpion, clinging on for grim death as the beetle unwittingly flew it to pastures new.  And when was the last time you saw a lion do that?
A pseudoscorpion on the antennae of a Black-headed Cardinal beetle (pic courtesy of Jo Cartmell)