Thursday, 26 September 2013

September Summary: New beginnings

This has never been my favourite time of year as it usually signifies the end of things – life slows down, flowers disappear, invertebrate diversity drops, the grass turns yellow, evenings creep in earlier and the mornings take their sweet time to get going. Migrating birds, such as Swallows and Martins, ram this point home by flying thousands of miles, risking storms, starvation and predators just to get away from it all. This time last year, sitting in my portacabin next to an aircraft hanger, a sense of poignancy pervaded.

The last of the dragons - a female Migrant Hawker, one of the latest active dragonflies

However, this year feels a little different as September has signified the beginning of new things. With the added help of other naturalists I have been squeezing in as many different ecological surveys as possible and we still have some exciting new ones to come including fungi, small mammals and pond invertebrates. I have been trying to cover as wide a range of species as possible.

The rare Bechstein's Bat we found earlier this month in Brockley Wood, North West Zone

The removal of American Signal Crayfish continues in a section of the River Mole - they love the spam.

The most commonly found species in our dormouse boxes - a Copper Underwing Moth

So there is life out there other than Craneflies!

The two main components of our Biodiversity Action Plan consist of monitoring wildlife, then hands-on conservation work to improve habitats. As the main survey season ends, our autumn practical tasks are kicking off with activities such as dead-hedging, reptile and amphibian hibernacula construction (a dug pit filled with rubble, logs and brash) and thinning out of old and dense tree plantations.

Airport volunteers opening up a woodland ride into Upper Picketts Wood. This creates 
space for the remaining trees to reach their full, healthy potential...

...also allowing the sun's valuable energy to strike the woodland floor, benefiting groundflora and fauna

Our first airport staff volunteers of the season were the Accounts Payable Department, lead by West Sussex County Council's Volunteer Co-ordinator, Darren Rolfe and assistant Tom Weedon. The day was a definite success; no wind, no rain, no trees dropping onto volunteers plus only one piece of equipment went missing in the long grass - must be some kind of record!

Thinning out the young tree plantation, targeting the Crack Willow for removal

Ashley's Field with a well-supplied work station

I joke of course, all our volunteer days go more than smoothly here. This group were a fantastic bunch with bags of enthusiasm and together they made a great difference. I must say I’ve never seen conservation workers so well kitted out, I mean, a cafetiere in the middle of a field? Fair play... mine's an espresso macchiato, please!

Gatwick Greenspace Partnership (GGP) of the Sussex Wildlife Trust are the main conservation group here, carrying out community and environmental projects in and around Gatwick. I hear it has been nearly 20 years and they are still going strong. So when's the party, guys?
   Another aim of ours is to increase local awareness of GGP's work and to strengthen ties with the airport's numerous departments. Earlier this month, we set up a communications stand at the British Airways offices at Jubilee House, demonstrating the conservation works around Gatwick in order to engage the staff. 

Kevin Lerwill of Gatwick Greenspace Partnership and Phil Townrow of British Airways Engineering

Phil Townrow, aka 'Phil the Bin', also joined us on the day: an interesting British Airways engineer who is green of mind and passionate about reducing the environmental impacts of aircraft operations, through projects such as aircraft waste recycling and biofuel production. Another example of how much is going on behind the scenes of an international airport and how little is known about it!

British Airways has ground-breaking plans for a biofuel plant, due to start operating in 2015

And so looking ahead there will be no time to relax in October, with a final push on reptile and mammal surveys, a jam-packed conservation schedule and a brand new Gatwick Greenspace team member joining the ranks; the pace is now picking up on Gatwick's Biodiversity Action Plans.

A surprise visit by this Dunnock who flew into the portacabin - maybe it was after my hobnob biscuits?

Thursday, 19 September 2013

Roving Records - Land East of the Railway Line: 18/09/13

My usual route

I was massively frustrated recently after misplacing the battery charger for my camera, then upon finding it and charging it up, the lens had jammed! The camera on my phone doesn't quite pick up the same fine detail and I swear the stress of an infuriating touch screen has knocked years off my life.

This took many attempts - my old camera would have got this in much finer detail

Plenty of European Garden Spiders (Araneus diadematus) were hanging about today and I got great views of a male courting the female and then mating. Frustratingly, my video came out blurry so I'm not bothering to post it. 

Picture of male and female after the event. Meeeh. 

Ok, melodrama over! Today was blustery but warm with lots of insect activity, so I took the opportunity to do a day's general wildlife recording. Walking through Upper Picketts Wood and towards Goat Meadow, the Great Spotted Woodpeckers were 'check-check'-ing and a group of raucous Jays were arguing (or perhaps just discussing something important).

Female Cranefly (Tipula paludosa) - the pointy bit on the end is the 
harmless ovipositer, used for laying eggs

Upon entering Goat Meadow it was Cranefly-City, with my every step sending them up in droves. I must confess here these things are not my favourite (particularly at night in my room) and are the one thing which makes my hairs stand on end. They do however provide a bounty of food for birds and other animals.

Speckled-Wood Butterfly basking in a sunny patch

Plenty of Speckled-Wood Butterflies were about too, making the most of the blackberries and the remaining flowers of Common Fleabane. I must have left it too late in the day to check the reptile refugia as nary a Grass Snake was to be found. A couple I lifted had recently-shed Grass Snake skins under them, which I was especially chuffed to find as I am collecting specimens for a classroom display.

Fragments of a sloughed Grass Snake skin - sadly not very intact

Off to the woodland strip ponds. The newt pond water level is exceedingly low and the Fat Duckweed now covers it entirely. Luckily, the invasive Australian Swamp Stonecrop plant (Crassula helmsii) higher up on the banks is finally dying off after treatment with Glyphosate. I will be keeping a close eye on it. 

Pond 4 is our newt pond; all of that green is Fat Duckweed

I found this Buzzard feather on the banks - another good find for the classroom collection.

The air was cooling down and the clouds had gathered in. Reaching the excitingly-named Pond 3, I poked around the muddy edges and was annoyed to see more pesky Aussie Stonecrop has come up...
(Crassula helmsii)These fine fleshy leaves will eventually form a dense mat, 
swamping out all other vegetation

I was looking around at some nearby deer tracks when I almost stepped on this large and groggy Grass Snake! She was possibly hanging around the pond for some juicy amphibians, but looked rather cold and was moving slowly.
My steel-toe boot wouldn't have done her much good

Round yellow eyes, a yellow neck-collar and disjointed black markings 
show this to be a Grass Snake

She kept very still so I took this short video and then moved slowly off, leaving her to get on with her day.

Carrying on into Horleyland Wood and along the power line ride, I saw a lone Comma Butterfly fluttering around the trees. A bright blue male Southern Hawker Dragonfly was also on the prowl, chasing smaller flies over the bracken. 
Power Line Ride

I finally reached Horleyland Wood Pond which is normally a hive of activity for insects and birds. This afternoon the wind had picked up and all was quiet. 
Well, except of course for the odd low budget aircraft passing by.

And the winner of today's most annoying plant is... Agrimony! (Agrimonia eupatoria) Its bristled seeds use hairy mammals (such as myself), to disperse it about the place. I feel so cheap...

Wednesday, 4 September 2013

A very unexpected bat...

'On the very last day, at the final hour, just as they were packing up...' Funny how often it seems to go that way with natural history, a lesson on never giving up too soon!

Martyn Cooke and helpers, setting up a bat mist net on the edge of Brockley Wood

On the evening of Monday August 19th, a small group of us set off to the woods on a rather different kind of wildlife survey. Martyn Cooke of Surrey Bat Group is a licenced bat trapper and handler, currently working on a large project spanning the borders of Sussex and Surrey. Much is still unknown about bats in the UK such as their current numbers and their social and mating habits. I imagine that even less is known about bats living near an airfield! 

North West Zone with Brockley Wood, River Mole and grasslands

We set up two large mist nets and a harp trap at Brockley Wood with high hopes of capturing something. As the sun was setting we could even see bats flitting along Man's Brook. Our two mobile bat detectors were quickly switched on and we began picking up calls of both Soprano and Common Pipistrelles along the treeline.

Setting up the Harp Trap and an electronic lure

Bats are highly protected under both European and UK legislation and all trapping work is strictly licenced. The harp trap and lure was devised by Sussex University; basically a metal frame with vertical fishing lines strung-up between and a canvas collecting bag at the base. The lure is an ultrasonic loudspeaker which plays pre-recorded bat calls - not the usual calls made when bats are hunting or navigating, instead the social calls made when they are communicating with each other. This draws in curious bats which cannot detect the fine wires of the trap, so they bump into it and then slip unharmed into the bag below. 

Scrubland West of Brockley Wood. A great place for moth-chasing while the sun goes down.
(Photo by Joe Bicker)

After some time spent setting up the traps, then came the waiting game. We wandered about between the two nets, looking out for signs of anything caught up in it. Although we were detecting some bat activity nearby, tonight these nets remained determinedly empty.

Common Blue butterfly roosting in the dark (Photo by Joe Bicker)

We finally began packing up sometime before midnight, making the decision to take down the mist nets first and leaving the harp trap until the last possible moment. It was with baited breath that we approached the harp trap for the final time, trying not to get our hopes up....

Scored! 1 mystery bat (Photo by Joe Bicker)

....we struck bat! Such a great reward at the end of a long evening. It was difficult to tell which species this was right away. Martyn took a closer look and was pretty lost for words; this little lady turned out to be a Bechstein’s bat (Myotis bechsteinii), one of the UK's rarest bats! 

An exciting find: a rare female Bechstein's bat (Myotis bechsteinii) 

A Bechstein's in the hand is worth a thousand in the belfry... (Photo by Joe Bicker)

The southern counties of England from Dorset to Sussex are where Bechstein's bats are most likely to be found in the UK. This young female was actually within range of a known Bechstein's colony, but it was still a pretty unexpected find in a fragment of woodland next to an airfield!

Impressive ears match the impressive gape - important features for a night-time aerial hunter of insects (Photo by Joe Bicker)

Assistants Emma, Joe and James watch while Martyn takes the biometric data. 

Martyn is a trained expert in bat trapping and handling; first he determines the sex and general health, then takes various measurements such as weight and forearm length. He was able to determine she was born sometime in June and although slightly small for her age, her weight was within the healthy range. Afterwards the bat was released unharmed and we felt privileged to have been in her presence!

Moment of freedom: We didn't take up too much of her time and she flew quickly away from us

Our little Bechstein's call sequence, displayed visually here as a sonogram. 

As she flew out of Martyn's hand I made a recording of her ultrasonic echolocation calls. Taking these recordings and analysing them through smart computer software means we can get better at identifying individual bat species without capturing them. There is a chance we could have a small colony of Bechstein's using Brockley Wood and the mature trees along the River Mole corridor. Martyn will be continuing his work through trapping and setting up his passive bat-detectors around Gatwick's woodlands.

Soprano Pipistrelles in their mating roost

We also have several bat roosting boxes up around this and other woodlands which we will check and clean out each year. Here is a bunch of lovely little Soprano Pipistrelles (Pipistrellus pygmaeus) Martyn and I found last week, all huddled up in a sleepy bundle.

For more information about bats and the UK's bat species visit the Bat Conservation Trust website