Friday, 28 February 2014

February summary

Going on how busy February has been around this place, my fears about the impending loss of my social life this spring are well founded. Here are a load of photos summing up what we've been up to this past month:

Scrambling to the finish: coppicing and glade clearance with JS Agriculture in 
Lower Picketts Wood

We have opened up our glade close to this beautiful ancient Hornbeam

The spring firsts have already appeared and the online recording is picking up - Red Admiral butterflies and various Bumblebee species have been spotted also many birds have begun nesting. Snow Drops, Wild Daffodil and Dog's Mercury are all well underway in the woodlands, too.

Dog's Mercury - early woodland ground flora

Hazel catkins with their tiny pinkish red flowers

Amphibians have been quick off the mark this year and I saw our first lot of spawn much earlier this month.

Frog spawn in temporary pools in the grasslands; it might mean fewer predators but is still a risky practice

Common Toad hiding out under a reptile refugia

Tackling the scrub in Goat Meadow - West Sussex County Council Rangers and volunteers

We have now removed a significant amount of the encroaching Willow and young Oak trees which have been threatening our lovely wet meadow. Thanks to the WSCC guys Darren, Tom and their volunteers for coming out to do this; I think being whipped by the small Willow saplings and vengeful Hawthorn scrub might appear on future risk assessments!

Grass Snake hangout spot after a re-furb - now a fantastic Grass Snake boulevard strip of 
willow brashpiles and logpiles.

If you ever come out to volunteer with WSCC, you will note their passion for fine filter coffee and biscuits; also how they pack everything away with military precision...

 Quite literally. They are using army surplus ammo boxes!

I recently made up a display board on Gatwick for some biological recorders seminars, where local conservationists and naturalists congregate to rub shoulders, hear about new projects and updated wildlife records. These are some of my best pics of 2013.

Sorting through the malaise trap invertebrate samples is fun but starting to feel endless - some of my nearest and dearest have also been coerced into helping!

Easy to miss (and to get poked in the eye)

During our Winter Thrush surveys, I finally found some direct evidence of the Brown Hairstreak butterfly on site, in the form of these tiny yet distinctive eggs on the Blackthorn scrub.

Perfectly round with coral-like patterning - the caterpillar which hatches out of this will soon be munching on some tasty fresh Blackthorn leaves

Some extra Dormouse boxes were installed by Tom S. of Gatwick Greenspace Partnership and Gatwick's Environment Team. It seems however that they are not protected from random members of public with marker pens... Everyone's a comedian.

We got our first definite record of Badger on site, perhaps a year or so too late! Hopefully it wont be long now 'til we capture a live one on camera.

Tree-climber Allen from JS Agriculture assisted Martyn of Surrey Bat Group with moving old bat boxes from dizzying heights to more suitable locations. Before moving them, Alan opened each of the boxes to check they were empty, and was pleasantly surprised to come across these occupants...

According to Martyn, it is quite unusual to find the Brown Long-eared bats in this type of bat box (a 1FF Schwegler, which to me sounds like some kind of handgun). He had been hoping to get a confirmed sighting of this species onsite here for a while, although we have picked up their calls in previous bat detection surveys with Laurie.

Definitely one of the cuter bat species; this dosey couple were left alone to continue their napping

Alan was careful not to disturb them while taking these photos, but not much chance of that as they were in torpor (a sort of semi-hibernation). Also, in a few of these boxes were strips of honeysuckle bark... Possibly, some sneaky dormice are operating at height!

An old birds nest we fished out of a bat box with a suspicious amount of Honeysuckle 

The most abundant insect of the month award goes to the 7-spot Ladybird, 
lots can be found hidden under bark and leaves

Finally, our late winter bird surveys have pretty much become spring bird surveys with Chaffinch, Skylark, Reed Bunting and many others already in song. The Redwing are very loud at the moment with their pre-migration chatter, which I still think sounds like a flock of Siskin. Small mammals such as Short-tailed Voles and Common Shrews are abundant and active at the moment, as the mild winter has been easy on them. That reminds me of last autumn and how I got on the bandwagon for predicting a very harsh winter - that darn Eddard Stark got it completely wrong.

Thursday, 27 February 2014

Cut and run

While continuing to sort my malaise trap-trawl, I've found another blast from my past Zoology lectures... Cleg flies or Horseflies.

Microscope close-up of a Cleg Fly head (x5)

I'm seemingly better at recalling the darker, gruesome side of zoology. I also got to know these insects rather intimately while working in damp Sussex woodland gardens; prime Deer, Human and Cleg habitat. These stealthy, bitey beasties are blood feeders and for them, pretty much any large mammal will do.

Palp and the sponging labella (x10), protecting the nasty
 pointy bits which can just be made out in silhouette 

Only the females partake in blood meals as they need the nourishment to produce their eggs (the males are nectar feeders). The mandibles and maxillae (mouth parts) of the female are brilliantly adapted into pointy, hardened, stabbing structures. These are shoved through the skin and then rapidly scissor back and forth like the blades of a tiny, hellish hedgetrimmer. The fly then injects an anti-coagulant and sucks up your life's fluid.
The stunning psychedelic banding of the eyes fades after death but can still show up in good light

This less-than-subtle eating habit apparently works just fine for them; the theory being the pain-inflicted victim will be more concerned with assessing the wound than swatting the culprit. However, I am a vengeful being and I recall the book The Wasp Factory graphically documents some pretty inventive ways to dispatch insects...

A live Notch-horned Cleg I caught last summer. 
After freezing to photograph it some more, the colours faded.

In all seriousness, I only dispatch the ones I need to photograph and identify (and perhaps a few others for self-protection). Going by the brownish colour of the wings and the dented antennal segment, the above species is the Notch-horned Cleg, Haematopota pluvialis. Even if they do make my skin crawl (or run about flapping my arms), these little.... ahem, guys are awesome-looking and resilient; when one lands and you give it a full-on whack, even if your aim is only slightly off, it casually flies off unscathed. But beware, for it has not likely to have gone far...

Chrysops relictus - Twin-lobed deerfly. Distinguishable from a similar species C. caecutiens by the reddish tibia (leg segments) and the black chevrons on the abdomen

All Deerflies, Clegs and Horseflies belong to the family Tabanidae and in the UK we have about 30 species. Another type I regularly come across is the Twin-lobed Deerfly. These are agile and difficult to catch, but just last summer I rescued the botanist Giles and our volunteer Georgina from certain doom by potting one on Giles' head. 

This one also died by freezing; it got off lightly.

To be honest, I don't really have time for a Wasp Factory, plus freezing is much less messy.

Wednesday, 19 February 2014

Environmentally friendly

Last week, Gatwick's Environment, Health and Safety team got their (gloved) hands dirty, helping us put up 50 new dormouse boxes.

We were working within fragments of ancient woodland, over in the Land East of the Railway Line. Despite having previously detected signs of Dormice here, we are yet to find that definitive evidence of one curled up sleepily in a box.

A sludgy woodland trek

The team did an excellent job of getting the boxes up onto trees, seemingly enjoying themselves despite the now habitual rain and rivulets of mud. The boxes were put up in rows of consecutive numbers (no thanks to my lacking mathematics, leading to much confusion and switching boxes about...) which will make surveying all the easier in the seasons to come.
Tom S. of Gatwick Greenspace, 'papping' the team

So about an hour later than it should have been, we finally stopped for a well deserved tea and biscuit break. Before leaving the site, while looking around for signs of mammal tracks, I spotted this entire badger skull...

Badger skull found in Lower Picketts Wood. 
I like how the sagittal crest has a funky green mossy toupée

Badger skulls are pretty solid things, with the skull plate sutures well-fused and the bottom jaw often still connected to the base. They also have a large ridge towards the back called a sagittal crest, to which the strong jaw muscles would be attached. 

After a good clean up, the crest is slightly more obvious. It seems fairly small and I thought this might indicate it was a young badger. However, the teeth are also rather worn and an upper-rear molar looks badly infected (this now being the least of its problems.) There also seemed to be signs of recent badger activity very close by; some further investigation could be required by Gatwick Greenspace Partnership's Youth and Wildlife Rangers!

Tom's new friend, named in the honour of Environmental Secretary Owen Paterson
(O-Patz for short)

After lunch, it was back into the woodlands for some glade creation - we coppiced an area of the unmanaged hazel understory and several birch trees. All of the wood is kept on site, stacked into neat-ish habitat piles, maximising the space on the ground for woodland flora.

Of all the team, I'm not sure that Frank takes Environment, Health and Safety the most seriously.

Hand saws and tree loppers, along with grit and determination means we can achieve a lot in a short amount of time; we are now starting to feel on top of our winter habitat management targets. Around the place are signs that spring is just around the corner, meaning that time to complete last year's data entry is also running out...

Tops of bluebells

Wild daffodils

The 'dormouse boxing' team

A massive thank you again to all who came out to help and to Karen for organising. We hope to see you lot again on a drier day in summer!

Thursday, 13 February 2014

Ichneumon not a type of Pokemon, but actually a tiny parasitic wasp.

An ichneumonid or braconid wasp. Difficult to photograph through the microscope lense, 
my old camera was better for this!

I got excited when I first saw this under the microscope; I remember lectures on them at uni and how interesting they were. However, as they are very numerous in the malaise trap samples, the novelty has quickly worn off! Still, they are very beautiful and diverse.

Relatively big parasitic wasp (1cm in length) vs. small parasitic wasp

Parasitic wasps are an incredibly diverse group of insects with thousands of species in Britain alone. Like all other wasps, they have the three body segments, but the abdomen, antennae and stinger (ovipositor) are usually very long. The ovipositor is adapted for injecting eggs into other invertebrate eggs or larvae.

The ovipositor is maneuverable; here it is tucked under the abdomen. 
The sheaths or 'guides' normally enclose the ovipositor and help to guide and support it.

The wasp larva hatches out and feeds either within or on the body of the host; some sci-fi movies were almost certainly inspired by these little guys. Even poor ol' Darwin was quite darked-out by them, questioning why a benevolent god would ever create something with such a cruel lifestyle.

Their taxonomy (classification) is very difficult and instead of attempting to identify them, I'll be storing them indefinitely, saving them up for my retirement (which for my generation might be never). As well as ichneumon wasps, related groups such as braconids, chalcids, and eurytomids are likely present in our malaise trap samples, all of which make up a huge group with the general name 'Parasitica'. Some of these are used on a commercial level as biological control agents, keeping down your agricultural and greenhouse pests. Here is a selection of parasitic wasps I've come across so far:

This last one is possibly a gall wasp (Cynipidae). They are actually herbivorous and lay their eggs in host plants, often causing swollen growths called galls on leaves and stems.

Looking at stuff under the microscope is addictive and I've been putting in quite a bit of my free time sorting these trap samples. My make-shift portable invertebrate lab is coming along in leaps and bounds - I have most recently acquired a great big cardboard box!