Roving Records - North West Zone: 28/03/13

On Thursday I had a cold and muddy trek about the North West Zone while replacing our reptile mats. My mood and expectations reflected the weather, but the resulting number of species was surprisingly high!

My meandering route

Firstly while standing at the airside fence by the River Mole, I got a birding first for me at Gatwick… A male Wheatear which was poking about in the mud at the edge of the airfield (the airfield operatives have little to fear from tiny birds like this). A Meadow Pipit was also sitting on the fence calling loudly and a couple of Skylarks were singing hard.

   Walking through the Solar Panel field I flushed a couple of noisy Snipe. Pied Wagtails were performing aerial acrobatics and I found this Common Toad at the base of the hedgerow under a reptile mat.

Disgruntled toad (they all look disgruntled)

I then checked the Mink raft and found some vague tracks and some droppings...

Mink spraint with bone fragments

Mink spraint with undigested fur

A flock of about 14 Fieldfare took off from the River Mole and a couple of Reed Bunting were calling to each other. I wandered up the ridge and took in the panoramic of the river and runway. From the hedgerow bordering Brockley Wood, loud chattering and the beginnings of a descending song marked the presence of over 40 Redwing, so our winter thrushes are still hanging about!

The 2^nd worst picture of a Reed Bunting ever taken

Walking north of the hedgerow I entered the scrub and marshland to the west of Brockley Wood. Plenty of activity in here, 3 more Snipe and a Mallard Duck made a lot of noise as they took off. Blue Tits and Great Tits were zipping about, about five Meadow Pipits foraging and a few Goldfinches flying over. Wandering back to the Mole I disturbed a Grey Heron as I walked around the north of Brockley Wood, then witnessed an aerial battle between two Common Buzzards and four Carrion Crow.

   In the ruts of a vehicle track was a load of frogspawn. This happened last year too and the constant wet meant that some tadpoles actually made it to adulthood.

I then came across what looked like the possible remnants of a rabbit in the form of masses fur in the grass. I wandered back to the Mole and disturbed a juvenile Grey Heron. A Little Egret then flew over, a first for me on this section of the Mole although they have been seen before at Povey Cross.

Rabbit detonation test site

I walked back to Man’s Brook and heard a Great Spotted Woodpecker calling. I dipped into Brockley Wood, heard a Green Woodpecker, two Jays, a Wren and Longtailed Tits all sounding off. The large Redwing flock had all resettled north of Man’s Brook. Wandering to the southern part of the woodland I came upon what looks like a Wood pigeon-plucking post. Sparrow Hawk perhaps or Buzzard, anyone?

Wood Pigeon detonation test site

Back along the netted section of the River Mole parallel to the runway, a cheeky Grey Heron was casually winging its way past me under the netting back toward the opening... slow they might be but perhaps not as dumb as they seem!
   And so I am cheered and reminded that the cold will not win out, soon there will be even more to see. In Brockley Wood, the Hawthorn is poised and ready for that warm weather to hit...

Here is the resulting species list: NWZ March 13

Underwater excavations

A flood alleviation scheme is underway along Gatwick Stream just off Radford Road. This is a project to widen the channel and increase the water holding capacity of the adjacent grasslands.

Archaeological dig site along Gatwick Stream, LERL

An ancient piece of worked flint, fresh out of the Gatwick clay

I have never seen an archaeological dig before. So far this one has been beset by freak blizzards, a WW2 bomb scare, nosy ecologists, relentless rain and flooded excavation pits – the archaeologists assure me this is all quite standard stuff and they crack on with the work regardless. And I had thought JSA and GGP were weather-hardened!

Week 1, Day 1

Week 2, Day 2

Week 2, Day 3. What would Indy do?

But a little water doesn't stop these guys and girls, and the team are successfully uncovering flint items from around the Mesolithic period, which is about 10,000 to 5000 BC. Nomadic humans would have used their expert 'knapping' skills on this flint to create a variety of useful tools...

Flint fragment, possible evidence of the flint having been actually worked on this site

I don't know what this would be used for but I want one.

On the biodiversity side of things, this is a chance for the creation of another floodplain meadow, a species-diverse habitat which has become increasingly scarce. Wetland species such as Black poplar, Bur-reed, Meadowsweet, Flowering rush and Marsh marigold flourish in floodplains and support a great assortment of wildlife. Agricultural intensification and the lack of appropriate management have probably been the biggest cause of loss of wetlands.

Gatwick Stream as it stands at the moment: narrow channel and in places very steep sides

I have been on site each morning keeping an eye out for any breeding birds while JSA came in to remove the scrubby vegetation along the stream and future floodplain. Although the hostile weather seems to have kept ideas of nesting at bay, i have witnessed many aerial skirmishes within and between species including Pied Wagtail vs. Meadow Pipit and Blue Tit vs. Robin.

I keep a log of all the species I see out and about for this kind of work, here is a link to the list of what has turned up so far... Gatwick Stream Species March 13

Mink tracks, banks of Gatwick Stream

Black-headed gull tracks in the muddy fields

Roe deer hoof prints, showing an imprint of the rear 'dewclaws'

The team from Network Archaeology are going to be here for the next few weeks and I am excited to see what might come out of Gatwick’s ground next (humans being a part of Biodiversity history too!)

Gatwick’s habitat mosaic: The science stuff

The names of our two conservation sites reflect the (sometimes infuriating) tradition of airport acronyms...

NWZ: situated just above the western end of the airfield

 LERL: to the south-east of the South Terminal

However they are usefully descriptive names and 'ell', 'ee', 'arr', 'ell' (LERL) rolls off the tongue after a while. These two areas are made up of mixed habitats containing their own related niches of wildlife. Our aims are to conserve all of these habitats and enhance them. Were it not for the airport then these buffering pockets of land would probably not be here, instead being given over to housing development or agriculture.

Brockley Wood’s south-eastern edge

I am often asked why we go in and carry out such heavy duty habitat management; it can seem counter-productive hacking back the brush and young woodland instead of just leaving it up to nature. In the simplest terms, changes in land use and development by people have caused our landscape to become very fragmented. Ecosystems no longer function in the usual way and the isolation of habitats such as woodlands, lakes and grasslands tends to result in their containing fewer species and a less diverse structure. For example, if the last remaining field maple in a small woodland fragment died out, there would be less chance of re-colonisation from the surrounding area if there is no other nearby woodland. A few dominating species in a small area are also more likely to take over and out-compete others. So we intervene to maximise the diversity of the land we have left and prevent a few species from becoming overly dominant (in the context of the wider landscape).

Bankside coppicing along Man’s Brook, North West Zone

Recently we have begun rotational coppicing of shrubs and trees (ie. cutting back to ground level) to provide a range of different-aged scrub as it regrows. A richer variety of habitats is beneficial for biodiversity as it will suit a wider assortment of species. However, if coppice stands are neglected they can grow up again into tall canopy cover, shading out the smaller ground flora. If hedgerows are left uncut, they can grow out and become straggly, dying off in the centre and eventually becoming lines of large trees. Coppicing helps to keep the integrity of a habitat and maintain it in a medium-aged state.

Coppicing can affect environmental conditions such as ground temperature and light levels

With conservation pressures ranging from small scale to large, our best course of action is to maintain a high level of structural diversity in a dynamic system, so that these many small havens will make up a healthier whole and as many organisms will benefit as possible.

There are many very good reasons for preserving the biodiversity of our planet … I am not going to list them all here, instead I will refer you to this link (though I honestly don’t mind if you want to skip over point no.9): http://www.natureserve.org/consIssues/tenReasons.jsp

The thing which resonates the most with me about conserving biodiversity is Aldo Leopold's statement in ‘A Sand Country Almanac’:

   “ - if a missing cog or belt can render a car’s engine useless—how much more might a missing organism affect the health of an ecosystem whose complexity is overwhelming?”

Dormouse developments

On Friday of last week a new housing development was completed by the British Airways Engineering Volunteers in Gatwick's ancient woodland Horleyland Wood...

Dormouse box mounted in mature hawthorn with honeysuckle, Horleyland Wood

Torpid dormouse in a box, photo taken on a survey in nearby Crawley, 2012

As well as achieving pretty incomprehensible levels of cuteness, the hazel dormouse is an elusive wee beastie and the best way to survey for them is to tempt them in with luxury accommodation. Although I hesitate to use the word ‘fussy’ they sort of are... however by the same token they could be deemed good indicators of high quality woodland and levels of biodiversity.

A typical dormouse nest, photo taken at some nearby woodlands in Worth, 2012 

They tend to come out of hibernation around April and then start scoping out new accommodation for the breeding season. If their presence is confirmed then a licensed handler will be brought in to assist with weighing and sexing individuals, determining the health of the population. 

Dormouse bagged to be weighed and checked over, Crawley 2012

Due to their rapid decline in the past 100 years or so, the hazel dormouse is protected by law. Causes for the population crash are believed to be the loss of ancient woodland, fragmentation of woodlands, loss of hedgerows and unsympathetic woodland management; these issues we are confronting in our Gatwick Biodiveristy Action Plan.

The British Airways Engineering volunteers are a keen bunch with a zeal for helping improve the environment of Gatwick. They are very handy to have around with their technical skills and I will blogging all about their good work in the future.

Many thanks to Adrian Haines, Carl Treynor, Colin Sexton, Glyn Finch and Terry Sparrow of British Airways Engineering

A rarer-tree… The native Black Poplar

Black Poplar Species Action Plan

We have a new species at Gatwick! We know this because we put it there... Last Wednesday under the supervision of expert plant carer Nikki Coultrip from JS Agriculture, we planted our 10 rare native Black Poplar saplings along the River Mole floodplain.

The full scientific name is Populus nigra subsps betulifolia. This tree is native to the UK and is one of the rarest in existence; only a few thousand mature specimens remain in Britain and 33 of these exist in Sussex.

Buds still in their dormancy

We have followed the planting guidelines of Sussex Otters and Rivers Project and the next few years we will be keeping a close eye on these little guys, strimming the grass around their tree guards and making sure they are not swamped by surrounding vegetation.

Each got a pep talk: Reach for the skies, don't let those rabbits get to you,
keep your head above the flood waters

Centuries ago the British black poplar would have occurred naturally in floodplain woodlands. Unfortunately, naturally functioning floodplain woodlands are almost an extinct habitat, also this tree requires very specific conditions to reproduce and so right now only survives through plantings and cuttings.

The Sussex Black Poplar Working Group was established in 1998 and to date have planted over 4000 trees in Sussex river valleys. Every year along with Sussex Otters and Rivers Project, they help to hand out young black poplar trees to landowners who can plant them in their native habitat. You can find more info about the SORP at http://www.sussexotters.org/