Friday, 9 December 2016

Early winter bird surveys 2016 (Part 1)

Land East of the Railway Line: December 8th

Dawn breaks over the Gatwick Stream, and Tom Forward is about to have a date with destiny...

Actually, the date is with a Snipe, but this is not just any old Common Snipe (although we did see 7 of those); it's a little bit scarcer than that. He wanders along the wet flushes, keeping out a sharp eye...

A sudden burst of wings from the ground and it's off like a shot - a Jack Snipe! Another new record for our bird list at Gatwick.

Jack Snipe (Lymnocryptes minimus) RSPB

Common Snipe (Gallinago gallinago) RSPB

Much quieter than Common Snipe, the Jacks have a shorter bill and are a shorter, dumpier bird in general. The Common types will shoot off up into the air before you can get close, but Jacks can hold on until you almost step on them, then dropping onto the ground again after a short, low flight.
  A small flock of Meadow Pipits bounced past us through the air, and a Grey Wagtail descended rapidly down into the river channel.

Our next new discovery for this site is a Barn Owl roost in our 'Little Owl-Oak'. Not sure if the little-er owls would think much of their new neighbour....

White wash (owl wee) on the tree above what might be the Little Owl nesting hole

Barn Owl pellet

Poking our heads over the bank of the Gatwick Stream by the sluice gates, and were surprised to see a dark, sleek mammal gamboling in the water. American Mink are insatiably curious and this one actually came towards us, then hid in a small clump of rushes to check us out.

Not much of a photo of course.
How to tell apart Otter and Mink - a handy Wildlife Trust fact sheet.

Dashing back over grasslands to the next transect, and we were stopped in our tracks by a pair of Kingfishers zooming low over the grass. Although strongly associated with water courses, they are known to sometimes cut corners and even head into woodland habitat to do so. Hey, I would too!

Into the woods and a flock of Redwing were busy foraging in the understory. Winter thrushes vary what height they forage at depending on available food source. Towards the end of winter they feed more on the ground.

More white-wash beneath a mature oak - favored perching point for a Common Buzzard?

A Song Thrush sang from a distant hedgerow. A Wren and Robin were also in song; only a few birds do this through winter.
   At Dunnock corner, there were constant loud calls which signified the usual debauchery. They always seem to get louder in winter, kind of like my own family. I guess domestic drama helps to keep small birds warm. I still get Dunnock and Kingfisher calls mixed up, which after 4 years of these surveys Tom F. must be getting fed up with.

Through the woodland strip and out into Lower Picketts Wood, mixed flocks were abound of Long-tailed Tits, Blue Tits and Goldcrests. We checked a little closer through the binoculars but sadly couldn't turn any of them into a Firecrest. At the end of the transect, our trusty Treecreeper finally called.

The final species count for the morning was 33 (not 34, as I only recorded Common Buzzard when I returned to site at the end of the day):

Turdus merula
Black-headed Gull
Chroicocephalus ridibundus
Blue Tit
Cyanistes caeruleus
Pyrrhula pyrrhula
Buteo buteo
Canada Goose
Branta canadensis
Carrion Crow
Corvus corone
Coal Tit
Periparus ater
Prunella modularis
Regulus regulus
Carduelis carduelis
Great Spotted Woodpecker
Dendrocopos major
Great Tit
Parus major
Grey Heron
Ardea cinerea
Grey Wagtail
Motacilla cinerea
Jack Snipe
Lymnocryptes minimus
Corvus monedula
Garrulus glandarius
Alcedo atthis
Linaria cannabina
Long-tailed Tit
Aegithalos caudatus
Pica pica
Anas platyrhynchos
Meadow Pipit
Anthus pratensis
Mistle Thrush
Turdus viscivorus
Pied Wagtail
Motacilla alba subsp. yarrellii
Turdus iliacus
Erithacus rubecula
Spinus spinus
Gallinago gallinago
Song Thrush
Turdus philomelos
Sturnus vulgaris
Certhia familiaris
Columba palumbus
Troglodytes troglodytes

American Mink
Neovison vison
Eastern Grey Squirrel
Sciurus carolinensis

Barn Owl (roost)
        Tyto alba

Sunday, 30 October 2016

Still searching for Micromouse

We have conducted 3 consecutive seasons of mammal surveying now, targeting Harvest Mice for the Surrey Mammal Group genetics study. I can only describe the feeling as 'incredibly disappointed' when you do finally capture one of your target species, then it perishes on the survey.

Eurasian Harvest Mouse (Micromys minutus), deceased adult male

Ecological surveys help us to target our conservation efforts, providing important data for reports such as the State of Nature. We do not wish to put animals through undue stress, and it was unclear why this individual died in the Longworth trap. As per the best practice protocols, traps were generously stocked with bedding, food, sources of moisture and checked within the regulated times. Harvest Mice do however have very short life spans, so it could be this individual was just reaching the end of his natural life. 

And so, after this one and only capture of a micro-mouse plus several discussions with other Harvest Mouse surveyors, these are the things I have learned:

1. Harvest Mice are difficult to survey, despite finding plenty of nests on our site. The fluctuating weather, changing habitat use and population crashes could all be impacting on our struggle to catch these little critters.

2. Despite this unfortunate mortality, Harvest Mice are fairly resilient; after speaking with other surveyors it seems very few casualties occur with Longworth traps. The overnight temperatures were above the minimum recommended for surveys, so cold was unlikely to be a factor, but we still took the precaution of providing extra insulation for the traps.

Longworth trap on stand with bubble wrap plus layers of grass

3. Wood Mice are relentless. I've seen more Wood Mice this year than craneflies. Their adaptability and climbing skills are to be commended, and they are certainly not deterred by the experience of temporary captivity! In fact, they mostly seem to find the traps before the other mammals can get a look in...

4. Shrews are awesome and sometimes I wish we were studying Shrews instead.

Lucy Groves, keeper at British Wildlife Centre with a Pygmy Shrew

Shrews love these castors (fly pupae)

5. Tube traps are a faff and take about 3 times longer to clean than Longworth traps.

6. On this survey, the average occupancy of Longworth traps was 49.71% whereas tube traps were 42.33% 

Collating trap data

Adrian Ashley is a handy chap to know - he's both an ecologist and a bespoke jeweller! He has kindly serviced the Longworth trap mechanisms which were not working so well.

7. Traps stands can definitely help to reduce the number of Common Shrew captures, but do not deter Wood Mice one little bit!

Tom Simpson often raids the set of vampire films for us 

Traps off the ground are more likely to tempt in Harvest Mice and appeal less to Common Shrews

8. Let the record stand that Martyn Cooke has still never seen a live Harvest Mouse in the wild.

Our survey data ends up in 3 places; on the internal Gatwick database, online on iRecord (which feeds into the National Biodiversity Network Gateway), and with the Surrey and Sussex Mammal Groups. We will be discussing the merits of continuing these surveys and any new approaches we might take next year.

Below are a few of our mammal records from the past 2 weeks (photos by Martyn Cooke):

Pygmy Shrew (Sorex minutus)

Bank Vole (Myodes glareolus)

Wood Mouse (Apodemus sylvaticus)

Surprise! Not a mammal: Wren (Troglodytes troglodytes)

A huge thanks to all who have helped out these past two weeks of surveys, and to Jim, Lucy and Laurie for all your advice.

Wednesday, 21 September 2016

Summer summary: 2016

I've really dropped the ball on blogging this season, so this is a round-up of our busiest summer yet on the project.

   Firstly. some BIG news....

We did it!!

Gatwick Airport Ltd has won the 'Client Award' catergory in the CIRIA BIG Biodiversity Challenge. Our biodiversity project has been running for 4 years now, with thanks to great support from key people and various departments at Gatwick, plus the Gatwick Greenspace Partnership. The CIRIA certificate is another brilliant collaborative milestone and sits nicely alongside The Wildlife Trust's Biodiversity Benchmark Award, which we continually work to uphold.

Hannah Deacon, myself and Tom Simpson

The organisation CIRIA firmly believes that the construction industry, business and infrastructure can all do their part in preserving the UK's biodiversity. In the midst of unprecedented species decline and the loss of British countryside, this is becoming of vital importance in conservation.

Betony in flower along the River Mole, North West Zone (July 2016)

Summer conservation and habitat works:

We are incredibly grateful to all of our volunteers who have visited the sites and got stuck in this summer, as without you we would not have half a project! We've spent days with local businesses and Gatwick staff controlling Himalayan Balsam along rivers, managing glades in ancient woodlands and helping to fortify the woodland footpaths.

Himalayan Balsam flying through the air

Working along the River Mole in Gatwick Airport's North West Zone

Kevin Lerwill's regular team of Gatwick Greenspace volunteers make a great contribution to our sites, along with Tom's regular helpers, Harry and Robert, who are incredibly helpful on more technical tasks. Here they have installed a shiny new biodiversity information board, over at the Land East of the Railway Line.

Under no circumstances may we put any staples for posters in the new oak frames


At the North Terminal Staff Memorial Garden; our pollinator friendly plants are filling out the spaces nicely, with signposts in place displaying information about each plant. Next year we will begin recording the pollinating insects here for the Sussex University LASI 'Plants for pollinators' study!

Jubilee Staff Memorial Garden - planting for pollinators

Tom Simpson with Sussex Wildlife Trust conservation trainee Bruno

Bumblebee on Hemp Agrimony (Eupatorium cannabinum)

Ecological monitoring:

Two new surveys conducted this year were clearwing moths and Purple Emperor Butterflies. Clearwing moths can be tracked down with the use of specific pheromone lures, which we bought from Anglian Lepidopterist Supplies.

Our first crack at using clearwing moth pheromones

It was rather challenging to even find a sunny afternoon in June and July! After a few attemps, our work experience placement student Ellie was our lucky charm and behold, after just 5 minutes the Sallow Clearwing Moth did appear!

This tiny moth is a very scarce (Nationally notable B) and likely under-recorded species. At first glance it looks like an ichneumonoid wasp...

Sallow Clearwing Moth (Synanthedon flaviventris

We had no joy trying to tempt down Purple Emperor Butterflies from Oak canopies, despite using some incredibly stinky shrimp paste (apparently the males love to feed on noxious substances). However, with keen-eyed ecology volunteers like Ellie and Ryan, you don't always need a lure...

A White Admiral perhaps? But we can just make out two tiny eyespots... 

Thanks to Ryan's netting skills (and a local resident for supplying an extendable pole and gaffer-tape), we were able to get a closer look to confirm our identification...

Large indicative eye spot on the underside of the upper wing

Purple Emperor (Apatura iris) female, one of Britain's biggest butterfly species

This is another fantastic record for the airport! Finger crossed that next year we hope to photograph the male.

Happy surveyors

Not only have we had new invertebrate species this year, but vertebrates too! Our very first Slow-worm has turned up in the Land East of the Railway Line. This is a bit of a landmark moment, as in over 4 years of continuous monitoring the only reptile species recorded at Gatwick has been Grass Snakes. Wildlife photographer David Plummer visited our site last week, turned over the first reptile mat he came to and found a new species!

A coppery flash...

Slow-worms are neither worms, nor particularly slow! I've seen this little lady hanging around a few times since now; each time she nipped off quicker than I could get a picture...

Slow-worm (Anguis fragilis) 'The Flash', eventually caught yesterday by myself and Ellie

Back to Gatwick's Grass Snakes, and we've had good results on our surveys this year, with several more sightings of these incredible melanistic (all black) specimens...

Grass Snake (Natrix natrix) melanistic form

Juvenile with the barest hint of a yellow collar, but otherwise entirely black.

The DNA samples we collect will be sent off to Bangor University for further analysis. Their study will be looking at relatedness of unusually coloured Grass Snake to other populations around the UK and the European sub-species.

Martyn Cooke of Surrey Bat Group has also sent off samples for DNA testing, from droppings collected at the bat roost in Charlwood Park Farmhouse. He was able to confirm they are Whiskered Bats (Myotis mystacinus), which are one of several species we've been detecting along the River Mole corridor.

Sleepy Brown Long-eared Bat (Plecotus auritus) waits patiently while having his box cleaned out

After our final bat box checks for 2016 (I think we now have around 75 boxes in total), we have confirmed Brown Long-eareds, Common Pipistrelle and Soprano Pipistrelle all in residence.

Ellie and Ryan on a beewalk survey along the River Mole

Rina Quinlan assisting on our reptile surveys

Tom Forward and Ellie on our breeding bird survey

We've hosted a wildlife week, a wildlife day, monitored a whole suite of protected species, recorded declining invertebrates, conducted ecology training courses and natural history group meetings, with many experts giving up their valuable time to help uncover Gatwick's diversity of species. As we go into autumn the work doesn't stop, with more ecological monitoring and habitat works yet to come!

A final big thank you to Royal Holloway University Ecology placement student Ellie Stradling for all her time, commitment and wildlife charming skills this past summer. Please come back again soon!

Ellie and a Southern Hawker Dragonfly (Aeshna cyanea)