Monday, 25 March 2019

Airport Bryology (March 2019)

A couple of weeks ago, Brad Scott visited our site to continue his discovery of Gatwick's bryophytes (mosses and liverworts) which inhabit the surrounding landscape. In just one day he recorded well over 40 species and even found something new and exciting to the airport!

A community of mosses; swirls of Cylindrical Beard-moss Didymodon insulanus

Bryophytes are small plants with no vascular tissue, mostly living in damp places, although some are surprisingly drought-tolerant. These tiny, ancient life forms are important pioneers of bare ground and vertical surfaces, such as walls and tree bark, where other plants often cannot gain a foothold. On just one old willow tree along the River Mole, we found around 10 different species of mosses and liverworts.

Brad Scott and volunteer Donald along the River Mole at Povey Cross

They provide ecosystem functions; trapping particulate organic matter, minerals and water, often changing the nature of substrate and making it more habitable for other lifeforms. Other colonists then able to take hold include fungi, small vascular plants and microscopic invertebrates such as springtails and mites, forming ecosystems of interconnected lifeforms on a tiny scale.

The hollow of an old Willow tree is a microhabitat in itself

I had some fun using a cheap macro lens clip for my smartphone, taking close-up shots of the specimens Brad was identifying. Some mosses have been assigned common names to try to make them seem more familiar and accessible, however it is debatable how helpful these names actually are!

Elegant Bristle-moss Orthotrichum pulchellum with fruiting capsules


Grey-cushioned Grimmia Grimmia pulvinata

Forked Veilwort Metzgeria furcata

Lecanora chlarotera - a lichen without a common name

Brad's find of the day was the tiny rare liverwort shown below, Fossombronia caespitiformis. The leaves are obscured by the moss in the foreground, but the fruiting bodies are the little black balls on the end of the stalks. These plants can only be identified to species by looking at the decoration of spores (which Brad tells me is not as hard as it sounds!). This one is very exciting as it is nationally scarce and hasn't been recorded in Sussex or Surrey for ages.

Fossombronia caespitiformis subsp. caespitiformis 
(apparently the common name for this one is Spanish Frillwort)

Fossombronia spores and spiraled elaters (photo by Brad Scott)

Brad is also an avid recorder of springtails (collembola); tiny invertebrates only a few millimeters in size, which are related to insects but don't quite qualify as they have internal mouthparts.

Isotomurus gramineus, a fairly commons species found next to the rare Fossombronia 
(photo by Brad Scott)

I didn't manage to photograph any springtails myself, but a few other tiny invertebrates managed to keep still for long enough for me to get my lens up close.

A juvenile crab spider, I think the species is Xysticus cristatus

I got rather overly distracted by a battle between two ants within an (Orthitricum?!) moss...


I think these are two different Lasius species; the black one being Lasius niger and the pinkish one Lasius flavus.



It went on for so long, I didn't have time to see who was the victor!

Many thanks to Brad for all of the identifications (and corrections!) for this blogpost.

Thursday, 24 January 2019

Gatwick's turtle tally

As you might imagine, the importation of exotic animals and plants is well enforced at UK airports. However, there are still occasional strange reports from 'round these parts, such as a group of Siberian Chipmunks witnessed running through the northern long-stay car park, or a Harris Hawk loose in the woodlands to the east. Most of these records are likely releases or escapes from private collections, but there is also a chance of things becoming naturalised in the wild.

Chinese Pond Turtle Mauremys reevesii (photo by Anthony Jones)

Last week's mystery was uncovered by a team of landscaping operatives, who while clearing a ditch airside at Crawter's Brook, spotted a tiny turtle. At only about 10cm in length they could easily have missed it, so it was quite a lucky find. The Animal Reception Centre (ARC) at the airport usually receives non-native animals which come in via aircraft; to have something exotic retrieved from the airside landscape is very unusual.


Crawter's Brook runs approximately 1 mile the length of the airfield

The tiny reptile was deemed to be in poor health, and permission was quickly given to transport it to the National Centre for Reptile Welfare (NCRW) at Hadlow College. Chris is an exotic reptile and amphibian specialist, who told me that despite the myriad of released terrapins living in UK waterways, this particular species (Chinese Pond Turtle) is very rarely encountered. It is sadly an endangered species in its native range in Asia (due to competition with non-native invasive turtle species), but a popular one to keep in captivity.

Glen this week; apparently his shell is rather off-colour (photo by Chris Newman)

We cannot know how long our little pal Glen (named for Glendale Landscaping Services) has been living on Gatwick's airfield, or how exactly he got there. After some days recuperating in controlled environmental conditions, his health has picked up and he is much more active, although he seems to have ongoing problems with his eyes.

The recuperation tank; Glen will eventually be re-homed into specialist care

We revisited the exact spot where Glen was found to have a closer look, but no other turtle chums were spotted. Which brings us to 'Turtle Tally', a citizen science project due to be launched by Hadlow College in spring, to collect sightings from the general public of turtles loose in the UK. Perhaps we will find there are more Glens out there than previously thought...

I am still collating a master species database for the airport landholdings (as more and more historical data comes out of the woodwork!), allowing us to keep track of the wildlife occurrences at Gatwick. If anyone happens to have unusual records or sightings from around the airport, whether historical or recent, please do get in touch via this blog's email account!

Monday, 31 December 2018

Wildlife calendar year at Gatwick

A selection of wildlife commonly found on the biodiversity sites, landside at Gatwick Airport.

January


Roe Deer - Capreolus capreolus

Our largest mammal species on site. I've also seen Fallow Deer very closeby, but never actually within our site boundaries.

February



This isn't a fungus, but is actually a type of bacteria called Nostoc commune; a colonial species of cyanobacteria.


Cyanobacteria are thought to have converted Earth's early atmosphere into an oxygen-rich one. It occurs extensively on the bare clay soil around the North West Zone and from a distance resembles squished rabbit poops.

March


Common Toad - Bufo bufo

We often find Toads under the reptile matts long before the Grass Snakes wake up from their winter sleep. Breeding occurs in the ponds and within the reedbeds along the River Mole. Unlike frogs, Toads lay their eggs in long strings.

Toad spawn, North West Zone

April

Bluebells Hyacinthoides non-scripta. Horleyland Wood

Found throughout the woodlands at Gatwick, this ancient woodland indicator species crates a heady scent on warm spring days.

May


Not a mirror image, but in fact a mating pair of Eyed Hawk-moths Smerinthus ocellata, spotted by Tom Forward along the River Mole grasslands.


June

Grass Snake  - Natrix helvetica

Our most common reptile species at Gatwick; widespread across both sites but they are particularly found of the grassy margins of scrub areas.

July

Platystomos albinus - (a type of fungus weevil)

This is a Nationally Notable B species, found in a well-rotted pile of oak and willow logs. It may not seem obvious from the pic, bit this little dude measured only about 1cm from nose to rear! (Thanks to Graeme Lyons for correcting my I.D on this one).

August



A colony of these Willughby's Leafcutter Bees (Megachile willughbiella) set up shop in a bee hotel constructed by Tom Simpson's volunteers.


Leafcutter bee nest

September


Harvest Mouse - Micromys minutus

One of our smallest mammal species, these tiny mammals weigh in at around 5g. Their nests
are commonly found in the reed beds along the River Mole.


October

Brown Long-eared bats - Plecotus auritus

Arguably the cutest bat species on site, they often utilise the bat boxes in the Land East of the Railway Line. In order to open and check bat boxes, a licence holder must be present, which in our case is ex-air traffic controller Martyn Cooke.

November


Eyelash Cup Fungus - Scutellinia scutellata. Upper Picketts Wood

These tiny and beautiful fruiting bodies are commonly found on very damp, well-rotted wood.

December


Tawny Owl Strix aluco

It just so happens that Tawny Owls are the subject of a current BTO survey, which members of public can also join in on.


Happy New Year everyone and all the best for 2019!!

Friday, 14 December 2018

Early Winter Bird Survey - North West Zone 12/12/18


This morning was the start of a real cold snap here in Sussex, which always seems to tie in with our North West Zone bird survey transect. Tom F. and I set off along the northern side of the airfield fence a little after sunrise, giving the birds some time to get moving and active. Tom commented right away that this was a spookily quiet morning...


A group of Meadow Pipits are typically the first birds we come across, bouncing along the airfield fence. A Robin and several Dunnocks called sporadically, hidden away along the banks of the River Mole. Our first red-status species was a Song Thrush, giving it's subtle 'tseep' alarm call as it fled, nipping down into the river bank vegetation.



Down on the floodplain it truly felt bone-achingly cold. The reed beds seemed devoid of life, then a fiesty Wren struck up an alarm call as it faced us off from the top of a reed. Finally, a Reed Bunting called, although only faintly and with no replies forthcoming. It really felt like the birds hadn't got out of bed yet.


Further along the floodplain, we caught the distant calls of Water Rails. These secretive birds seem to be more vocal in winter, and their call is highly weird. If you happen to be standing right next to one when it sounds off, it's pretty alarming!





Over to the scrub west of Brockley Wood, a few Blue Tits and Long-tailed Tits were foraging together on the woodland edge. A sole Green Woodpecker headed off calling and a group of Wood Pigeon broke from the trees. Over in woodlands, a distant Nuthatch called.


This sheltered patch of grassland is one of my favourite spots in summer, dense in long herbaceous vegetation and absolutely humming with invertebrates. In winter however this tends to be the favourite patch of another highly-secretive and red-status bird; the Woodcock. We flushed one from the low scrub; its low, whirring flight really does give the appearance of a giant bat. 



Poking our heads into the north of Brockley Wood, we were hoping for some Redwing activity, however the flocks were conspicuously absent from the site this morning. The collective alarm calls of  Blackbird, Magpie and Wren indicated the presence of an avian predator, likely a perched-up Tawny Owl or Sparrowhawk. Whatever it was then moved off, as the alarm calls rapidly followed it through the wood.


Our final section of grassland along the River Mole turned up two Common Snipe, which had been well hidden in the rushes. One put on an amazing display, flying a wide loop over the environment bund and then skimming low past us at about waist-height. This whole transect was again peculiarly quite, and surprisingly one of the most numerous birds was Bullfinch; we counted a total of 6.



At the very end of the transect we had a buzz of excitement in the form of a perched Sparrowhawk, apparently causing upset with the resident Ring-necked Parakeets. It casually took off over the trees, leaving in its wake a string of songbird alarm calls.


Final species count = 34

Common name
Species
Blackbird
Turdus merula
Blue Tit
Cyanistes caeruleus
Bullfinch
Pyrrhula pyrrhula
Buzzard
Buteo buteo
Carrion Crow
Corvus corone
Chaffinch
Fringilla coelebs
Coal Tit
Periparus ater
Dunnock
Prunella modularis
Goldcrest
Regulus regulus
Goldfinch
Carduelis carduelis
Great Spotted Woodpecker
Dendrocopos major
Great Tit
Parus major
Green Woodpecker
Picus viridis
Grey Heron
Ardea cinerea
Jackdaw
Corvus monedula
Jay
Garrulus glandarius
Long-tailed Tit
Aegithalos caudatus
Magpie
Pica pica
Mallard
Anas platyrhynchos
Meadow Pipit
Anthus pratensis
Moorhen
Gallinula chloropus
Nuthatch
Sitta europaea
Reed Bunting
Emberiza schoeniclus
Ring-necked Parakeet
Psittacula krameri
Robin
Erithacus rubecula
Siskin
Spinus spinus
Snipe
Gallinago gallinago
Song Thrush
Turdus philomelos
Sparrowhawk
Accipiter nisus
Treecreeper
Certhia familiaris
Water Rail
Rallus aquaticus
Woodcock
Scolopax rusticola
Woodpigeon
Columba palumbus
Wren
Troglodytes troglodytes

Monday, 1 October 2018

Gatwick's first butterfly transects

Clouded Yellow Colias croceus f. helice, North West Zone 
(Photo by Vince Massimo)

This was our first year of conducting a butterfly transect in the North West Zone (NWZ). I had expected it to be at times quite trying and physically demanding... and THEN we had the heat wave!

Our NWZ transect is 2.5km in length, which comprises of a route along the River Mole corridor, over the large clay mound (where a colony of Long-horned Bees reside) and the edge of Brockley Wood. We completed 26 weeks of surveys and the almost-constant sun allowed us to easily fit in surveys during the optimum weather conditions.

The UK BMS website has a useful reporting feature, which makes it quick to work out a few simple stats:
We recorded 2,885 butterflies over 26 weeks
The highest count of the year was 509 butterflies on July 8th.
The average temperature for the walks was 20 degrees and level of sunlight was 82%


Peak counts for the top 5 species in NWZ:
  • Meadow Brown peaked at 197 species (June 17th)
  • Gatekeeper was next at 157 (July 8th)
  • Small Skipper at 129 (July 1st)
  • Ringlet 115 at (June 24th)
  • Common Blue peaked at 42 on June 3rd then had a resurgence on July 22nd, reflecting two main flight periods

Low abundance species (single records):
  • Green Hairstreak
  • Clouded Yellow
  • Painted Lady
We had only two records for Small Tortoiseshell, both occurring in April.

























With a regular group of volunteers the transect progressed well, so we decided to set up a second transect in the Land East of the Railway Line (LERL). We only began this about midway through the season, it doesn't result in a full year's worth of data, but still good to have it up and running.

A few highlights via photos taken by Vince...

Marbled White Melanargia galathea

Purple Hairstreak Favonius quercus

Clouded Yellow Colias croceus f. helice

Ringlet Aphantopus hyperantus 

A huge thank you to all the surveyors who volunteered their time for butterfly recording at Gatwick: Vince, Peter, Sue, Abigail, Tara, Yasmin, Emily and Ryan. I can't wait now until spring... only 27 weeks to go!

The 2018 species list:

Site
Common Name
Species name
NWZ
LERL
Small Skipper
Thymelicus sylvestris
Essex Skipper
Thymelicus lineola
Clouded Yellow
Colias croceus

Large Skipper
Ochlodes sylvanus
Dingy Skipper
Erynnis tages
Large White
Pieris brassicae
Small White
Pieris rapae
Green-veined White
Pieris napi
Orange Tip
Anthocharis cardamines
Green Hairstreak
Callophrys rubi
Brown Hairstreak
Thecla betulae
Purple Hairstreak
Favonius quercus
Small Copper
Lycaena phlaeas
Brown Argus
Aricia agestis
Common Blue
Polyommatus icarus
Holly Blue
Celastrina argiolus
Red Admiral
Vanessa atalanta
Painted Lady
Vanessa (Cynthia) cardui
Small Tortoiseshell
Aglais urticae
Peacock
Inachis io
Comma
Polygonia c-album
Silver-washed Fritillary
Argynnis paphia
Speckled Wood
Pararge aegeria
Marbled White
Melanargia galathea
Gatekeeper
Pyronia tithonus
Meadow Brown
Maniola jurtina
Small Heath
Coenonympha pamphilus
Ringlet
Aphantopus hyperantus
Brimstone
Gonepteryx rhamni

Total no. species = 29 NWZ    19 LERL

Previously recorded but missing from our transects in 2018:
Grizzled Skipper - NWZ
Purple Emperor - NWZ
White-letter Hairstreak - NWZ & LERL
White Admiral - NWZ & LERL