Tuesday, 30 June 2015

What lies beneath

In early June, at the South Terminal long-stay car park, a small group of ecologists gathered for Gatwick's final newt survey of the season. 

Not the most obvious of wildlife settings, but a secret short cut from here takes us through to some secluded woodland ponds. These ponds seem to have been here a long time and are home to five different species of amphibian, all native to the UK. 

The infamous Bill Wadsworth of Chris Blanford Associates

Great Crested Newts are fully protected under UK and European law and you must be a licence holder to survey for them. Bill is a newt-extraordinaire, monitoring this pond over a number of years since the completion of a new water treatment area nearby. Counting newts means that we can estimate the population density, keeping an eye on the population health and ensuring that no long term impacts are apparent.

Specialist torches are used (1 million candle power) in order to cut through murky waters. The first thing we came across on this evening was....

Mirror Carp (Cyprinus carpio); a massive one at that

Not quite what we were hoping for! Fish are voracious predators of newts and so do not often occur together, however this particular pond is one we are restoring for amphibians. The fish were artificially introduced here, so this coming autumn electrofishers will humanely remove and relocate them, relinquishing the pond back to our amphibian friends. 
  Over to the next pond; now this is more like it....

Great Crested Newt (Triturus cristatus), male

Either a Smooth or Palmate Newt (Lissotriton sp.), female

Torching is quite a challenge in these particularly murky waters, resulting in a number of double-takes at a leaf-like-newt. Or is it a newt-like-leaf?

Common Toad (Bufo bufo)

Common Frogs and Common Toads are also quite a challenge to spot, until you get your eye in, then they are blooming everywhere!
   Another method to survey for newts is bottle-trapping, which might sound ridiculous but is very effective...

Preparing bottle traps

When Fat Duckweed dominates the pond surface, torching is out and bottle trapping is in

Trapping newts is quite an intrusive way to count them, so we only do it here when absolutely necessary, again with appropriate licences. The traps are placed out the day before and then collected back in very early the next morning; we want to minimise any disturbance to these guys and gals.

Great Crested Newt (Triturus cristatus), female
 This one is quite odd in lacking belly pattern

Great Crested Newt (Triturus cristatus), female

Ecology student Mark gives us a hand with the traps

Newts love hitting the bottle

Smooth Newt (Lissotriton vulgaris), male

Palmate Newt (Lissotriton helveticus), male, 
with heavily webbed back feet and a filamentous end to the tail

Palmate Newt (Lissotriton helveticus), female. 
The throat of this species tend to be rosy pink and unspotted

The breeding season is over for another year and most newts are leaving the ponds, but the next generation are still there, lurking just beneath the surface...

Friday, 26 June 2015

Early invertebrate survey (the one that got away)

Wet weather and blustery conditions means that winged insects struggle to fly, instead staying hunkered down low in vegetation or hidden away in nooks and crannies (I wish it was the same for us ecologists).

Land East of the Railway Line

Earlier in the month, on a rare day of both sun and stillness, Surrey Wildlife Trust entomologist Scotty packed up his van and invertebrate surveying kit, stopping by to see what is happening under the radar of all the tourists and jet-setters.

Preparing sample tubes

Our task today was to check out some habitats which were missed off the previous surveys and needed looking at more closely. We've been keen to get back out to the Gatwick Stream since the flood alleviation project has come to a close...

Gatwick Stream grasslands

Wetland scrape with Great Reedmace (Typha latifolia), Gatwick Stream grasslands

Now the floodplain has had a full season of vegging up, in places it is looking quite stunning (albeit with the odd random exotic plant species cropping up). As the vegetation advances, the invertebrate lifeforms also begin to recolonise...

Agelena labyrinthica - Labyrinth Spider on dewy web

Underside of a Long-Jawed Orbweaver (Tetragnatha sp.)

A species of large diving beetle (Colymbetes fuscus)

Red-headed Cardinal Beetle - Pyrochroa serraticornis

Invertebrates form the essential base of many food chains and so can be excellent indicators of habitat quality. By seeing what species are dominating or what is absent, we can judge the success of our habitat management, then in a few years time we resurvey to measure the progress.

Gatwick Stream channel with its sculpted clay cliffs

The Gatwick Stream banks are still yet to green up, but even bare clay is appealing to some lifeforms, creating an interesting habitat matrix, suiting mining bees, mason wasps and beetle species. Even some birds too...

Kingfisher burrow

Here we had a brief interlude for some ancient bottle-collecting along the banks. These must have been underground for some time and washed out during the river re-alignment works...

Early 20th centruy Tizer bottle. "That belongs in a museum" 

Indiana Jones moment passed, it was time to look more closely at the pollen and nectar-gathering species...

Bumblebees on Fodder Vetch (Vicia villosa). Most were workers of either the Buff-tailed or White-tailed variety, as well as Tree Bumblebee

Corizus hyoscyami, aka the Cinamon Bug, or Squash Bug, or Scentless Plant Bug. 
(The perils of common names for invertebrates)

Over to another grassland area; Ashley's Field which is the subject of our green hay strewing project and home to our Honey Bee apiary, aka the 'Gatsbees'...

Ashley's Field - perhaps a little heavy on the Buttercup

Hitch-hiker: another Long-jawed Orbweaver

Into Upper Picketts Wood our the way to Goat Meadow, we stopped off to take a closer look at the understory.

Nut Weevil (Curculio nucum

...giving Scotty a nip with its sharp, finger-boring mandibles!

Mr Finger-borer unfortunately took a nose-dive before I could focus for a close up.
   Over to Goat Meadow; a quieter, sheltered area of grassland. This lovely scrubby matrix is a real haven for butterflies and Grass Snakes. 

A few molluscs have made their way here too...

Wandering Pond Snail (Radix sp.)

Brown-lipped Snail (Cepaea nemoralis)

Scotty spent some time sweeping and beating the willow and oak scrub, turning up many interesting things including this funky little micromoth...

Alabonia geoffrella, with its funky, upturned labial palps

And I swept this punky caterpillar...

Vapourer Moth caterpillar (Orgyia antiqua). 
The adult female moths are wingless and emit pheromones to attract in winged males

14-spot Ladybird (Propylea 14-punctata)

A type of treehopper (Centrotus cornutus), one of only two species which occurr in the UK

Glowworm (Lampyris noctiluca) larva, commonly found under the reptile refugia

Scotty then called me over to take a look at this little beauty... 

A lovely little Jewel Beetle (Agrilus sp.)

Jewel Beetles are not very common in this area, so this could be quite an exciting find. We cooed over it for a bit, turning it over in the tube and I popped it back onto the willow leaf to get a better snap. It didn't stick around for long and this was as good as it got...

Agrilus sp. indet. cf.bickerisabloodymindedliberator

On handing Scotty back the empty tube, his face fell... Apparently there are over 3000 species of beetle in this single genus and he needed to check it under the microscope to identify to species level! Ooops.

...Fly, my pretty!

Monday, 22 June 2015

Late Breeding Bird Survey (Land East)

Today, Ecology students Mark and Elliott were joining us from Royal Holloway University (my old stomping ground!) so we were hoping to come up with some good birding action...

A soggy start at the Land East of the Railway Line

At the very start in the Gatwick Stream grasslands, a cloud of around 45 Swifts were drifting above our heads over the water treatment works. There were multitudes of scruffy-looking Jackdaws and Carrion Crows, apparently in post-breeding condition as they were moulting and missing wing feathers.

A lone Carrion Crow

Further to the east, a Stock Dove performed the classic 'paper aeroplane' display flight right over our heads while a Green Woodpecker flitted back and forth to a small patch of woodland, possibly feeding its chicks hidden somewhere in the woodland fragment.

The damp weather meant that bird activity was quite suppressed, but this gave an opportunity to reacquaint ourselves with those familiar species which we take for granted, such as the ubiquitous and relentless Wren, powering through even the worst weather!

Wren song with the call of a Great Spotted Woodpecker in the background

The alarm call of the Wren is generally a fast 'tec-tec'... 

Whereas a Robin call is more like a 'tic-tic'...

Birch, Ash, Alder and Scots Pine make up the canopy in Upper Picketts Wood

In Upper Picketts Wood, a large band of Blue Tits were moving together in a roving flock; potentially several family groups which had banded together...

A  Coal Tit then sang out, seemingly at Tom Forward's request...

The twittering of young birds and the alarm call of an adult Chiffchaff alerted us to something in the bushes...

Out of the woods and a brief grassland interlude.... All was pretty quiet and rather waterlogged in Goat Meadow.

Goat Meadow, a scrub and grassland mosaic

The song of a Robin, being slightly upstaged by a Blackbird

The dampest, saddest Tree Bumblebee (Bombus hypnorum) you might ever see

In the woodland strip (our reliable Chaffinch hotspot), we had lovely views while the parents fed their chicks.

Really not the day to be without a weatherwriter

It was nice to hear the calls of both Treecreeper and Nuthatch in the same vicinity...



However, a lovely end to the survey with close up views of the same group of Swifts, swooping low down over the water treatment ponds...

And the calls of a few intermingled House Martins...

All in all a damp and dreary experience. Gonna have to break out the good biscuits to bribe the work experience guys back again.

Many thanks to Tom F., Mark and Elliott for your time and enthusiasm!

Our final tally was 28 species, actually a good count for this time of year:

1 Blackbird Turdus merula
2 Blackcap Sylvia atricapilla
3 Blue Tit Cyanistes caeruleus
4 Carrion Crow Corvus corone
5 Chaffinch Fringilla coelebs
6 Chiffchaff Phylloscopus collybita
7 Coal Tit Periparus ater
8 Dunnock Prunella modularis
9 Goldcrest Regulus regulus
10 Goldfinch Carduelis carduelis
11 Great Spotted Woodpecker Dendrocopus major
12 Great Tit Parus major
13 Green Woodpecker Picus viridis
14 Grey Heron Ardea cinerea
15 Grey Wagtail Motacilla cinerea
16 Jackdaw Corvus monedula
17 Long-tailed Tit Aegithalos caudatus
18 Magpie Pica pica
19 Mallard Anas platyrhynchos
20 Nuthatch Sitta europaea
21 Robin Erithacus rubecula
22 Song Thrush Turdus philomelos
23 Stock Dove Columba oenas
24 Swallow Hirundo rustica
25 Swift Apus apus
26 Treecreeper Certhia familiaris
27 Wood Pigeon Columba palumbus
28 Wren Troglodytes troglodytes