Rings around the world

Nightingale at Gatwick Airport (Photo by Dean Samsudin, 2020)

Back in May 2016, myself and volunteer Donald were carrying out a reptile survey in the North West Zone when a sudden burst of bird song erupted near my head; a Nightingale was the last thing I'd expected to hear that day! This is a real stand-out moment from my time at Gatwick. I nipped back that same evening to make a recording (this being back in the era of a busy night-time airfield). Ambient noise didn't put this energetic songster off...

 

Sound only clip (no image)

Nightingales arrive in the UK around late April, having migrated all the way from their overwintering sites in Africa. Checking Gatwick's pan-species list, there are few previous records of Nightingale within the airport boundary. It seemed in 1987 the Hilton Hotel car park (around 3km from the current spot) contained some good scrub habitat which was suitable for their breeding, however in 2021 this area is now a stand of semi-mature trees.

Corridors of good quality habitat are important for dispersing wildlife, especially for highly mobile species such as migrating birds. The River Mole diversion project was completed in the year 2000, resulting over 20 years later in a 3.5km length of meandering floodplain meadow, bordered by sloping species-rich grassland, graduating into scrub and mature woodland. 

North West Zone biodiversity area

Since that record in 2016, I've heard a Nightingale in the same spot on the River Mole 5 years out of 6; could it be the same bird returning each summer? Another male then set up territory along the River Mole in 2020, about 1km further downstream. This year they've both remained on site late into summer, therefore are very likely breeding. Two Nightingales on one reserve doesn't make a population, but along with increasing numbers of Song Thrush and summer-visiting warbler territories, it could indicate that our scrub and grassland mosaic is coming into peak condition.

River Mole corridor, July 2016

Our biodiversity areas are only a short stint away from the Knepp Rewilding project, itself a large 1,400ha estate of grassland, wetland and scrub, 22km away as the Nightingale flies (for comparison our NWZ site is only around 40ha). It also contains a heck of a lot of Nightingales. Anecdotally, this red-listed species seems to be having a few good years, with other additional sites popping up nearby. Could this be an overflow of birds fledging at Knepp? When local wildlife watcher Dean alerted us that the second Nightingale was sporting a silver ring on its leg this year, it meant we could possibly find this out...

Penny Green in the River Mole grasslands

The bird ringing scheme, overseen by the British Trust for Ornithology (BTO), gathers data on the survival, productivity and movements of birds, which is important in understanding why populations are changing. Recovered rings have told some pretty surprising things over the years, causing our estimates of wild bird life-spans and travel distances to be revised. It is an intensive undertaking which involves a lot of special training. Fortunately several of the ecologists we work with happen to be licenced bird ringers!

Jon Middleton is an aviation ornithologist for Birdstrike Management Ltd, who visits Gatwick Airport as a consultant several times a year. In his spare time, Jon is an avid bird ringer and after hearing about our two Nightingale territories, he offered his help with Nightingale Territory 1; the original, un-ringed male.

Just as the night was drawing in, we had success in our single mist net; a male Nightingale caught and gently handled by Jon. This happened to be Jon's first time with this species in the hand, so it was a double celebration. The first ever Nightingale to be rung at Gatwick Airport!

A few nights later, it was the turn of another crack team: Penny Green the Knepp Estate ecologist and her partner Dave, who were keen to capture the second male and check the ring reference number. It was a more intrepid route on that evening, setting up our mist net at Nightingale Territory 2...

Photo by Dave Green

Success came once again just as it was growing dark, exactly as predicted by Penny and Dave!

With the bird in the hand, Dave could clearly see the silver ring. The priority was to note down the reference number, before taking additional measurements for biometric data...

Male being checked for breeding condition

An incredibly gratifying moment was when Penny checked the Knepp ring numbers from last year; this is a match for their records! In fact, this guy was rung by Dave himself in August 2020. Having this information confirmed is super high value, showing how these birds use sites across Sussex for breeding as well as migration stop-overs. As Penny put it, this is a fantastic link between our two projects.

A check of wing length and plumage condition

What a beauty....

A Knepp-rung Nightingale on the River Mole at Gatwick (photo by Penny Green)

A bonus Lime Hawkmoth extracted from the mist net

Two Nightingales, a luxury pack of chocolate digestives, and a group of very happy ecologists at Gatwick Airport on two nights in June.

Photo by Dave Green

Airport biodiversity conservation in action

Last week we received a visit from around 30 Biological Sciences students studying for their course module 'Conservation in action'. The group was headed by Dave Goulson, Professor of Biology at the University of Sussex.

Clay slope overlooking the airfield and the River Mole; our Long-horned Bee nesting site

Within the broad topics of conservation biology and habitat management, schools of thought change as new science and experience comes to light. Conservationists must be open to feedback, analysing and reviewing their work, questioning the impacts and controversies of what they are trying to achieve. On Gatwick's sites, we have the added challenge of striking a balance between wildlife conservation and aerodrome safety.

Westfield Stream, airside. Areas closest to the airfield are kept as sterile as possible, reducing attractiveness to flocking birds or large mammals which could come in contact with aircraft

Horleyland Wood. Further away our areas are managed to encourage species diversity, perhaps even contributing in small ways to a push-pull dynamic for wildlife

The reality is that we are working with a large-scale operational hub incorporating many buildings, transport infrastructure and the people who operate and pass through it. Since the first bird strikes reported early on in aviation history, research on wildlife hazards at aerodromes has been a broad and contentious topic. It makes fascinating reading because almost every aerodrome has its particular set of circumstances presenting a unique case. Our ultimate priority is minding the safety of both wildlife and people when managing habitats around Gatwick, which means sometimes thinking outside the parameters of an idyllic nature reserve.

Ashley's Field. Showing the students our Grass Snake habitat enhancements and bee areas

The contrast of conservation management techniques was highlighted to the students after visiting the fantastic Knepp Estate Wildland Project near Horsham, West Sussex. This large landscape project (around 1,000ha) uses free-roaming grazing animals and the natural dynamics of succession to revert ex-agricultural land back into something more naturalistic. This practice of 'rewilding' is already producing some pretty exciting results at Knepp. On a much smaller scale at Gatwick, some of our areas have also been left to 'rewild', as small pockets of grassland which historically were used for pasture or agriculture were long ago abandoned as buffer areas around the airfield. 

Scrub West of Brockley. Searching for rare Brown Hairstreak Butterfly eggs on Blackthorn - it took the students only a couple of minutes to find one of these tiny eggs

No easy task - these eggs are only around 1mm diameter

However, due to the much smaller sizes of our sites and their overall fragmented nature, we can't expect the same large-scale ecosystem dynamics to come into play. Instead we intervene through techniques such as manual scrub clearance, coppicing and re-planting to maximise the diversity of the land we have left, preventing a few species or habitats from becoming overly dominant. This means that even in a small area, we can maintain a wide variety of good habitats benefiting a wide range of species. 

   Working with a commercial entity has also taught us greatly about mediating between differing agendas; nature wants to perpetuate whereas infrastructure wants growth, and often it would be the latter taking precedence over the former. Communication and information sharing is an incredibly important process in finding sustainable ways going forward and to avoid repeating past mistakes.

North West Zone. Sussex University Biological Science Students and research staff

Tom Simpson and I would like to sincerely thank everyone who came along last Friday for this tour of our sites; it was quite gratifying sharing what we are doing with future ecologists, conservationists and researchers. Hopefully we can continue to establish links with academic and research institutions, providing training, research resources and further developing our airport biodiversity project.

Record-breaking recorders

In the last 2 weeks I have been on holiday, been pretty unwell and been extremely busy preparing for the initial Biodiversity Benchmark audit here at Gatwick. As a result I haven't been able to get out in the field much, but happily I got my natural history fix last weekend after a biological recording day at the Knepp Estate in West Grinstead.

Mark Telfer and other pan-species listers, beating vegetation and catching invertebrates

Here I met an eclectic bunch of diligent, passionate and frankly hard-core naturalists, some of who are professional conservationists or ecologists, many who simply love the natural world and set themselves the lifetime challenge of observing as much of it as possible. These are the pan-species listers and I thoroughly enjoyed chatting with them to get a snapshot into their pursuits; from lichens and fungi, to beetles, birds and everything in between.

Mark using a pooter to collect up the tiny deadwood beetles for identification

 These guys and girls contribute an incredible amount to species records around Britain, often collecting data on lesser-known organisms and even discovering new unrecorded species. (Some may call it odd, I call it diligence that they travel so far in order to find a not-so-fresh deer carcass, donning their gloves and giving it a thorough cavity search for carrion-feeding invertebrates dwelling inside...) You can meet them and follow their progress on Mark Telfer's website: http://markgtelfer.co.uk/listing/
   I am rather new to ecology and seemingly much too distracted and indecisive right now to choose one species group to focus on learning. Below are my photos from the weekend, a very small sample of the showier species which we recorded:

Beetles:

A wasp-mimicking species of Longhorn Beetle (Clytus arietis)

Black-headed Cardinal (Pyrochroa coccinea)

Malachite Beetle Malachius bipustulatus (this one gave me a tiny nip)

Dragonflies and Damselflies (netted with my new insect net):

Azure Damselfly (Coenagrion puella)

Male and female Azure Damselflies in tandem (Coenagrion puella)

Female Scarce Chaser Dragonfly (Libellula fulva)

Blue-tailed Damselfly (Ischnura elegans)

Large Red Damselfly (Pyrrhosoma nymphula)

Moths (mostly from the overnight moth traps):

Brimstone (Opisthograptis luteolata)

Longhorn Moth (Nemophora degeerella)

Lime Hawk-moth (Mimas tiliae)

Pale Prominent (Pterostoma palpina)

White Ermine (Spilosoma lubricipeda)

Swallow Prominent (Pheosia tremula)

Poplar Hawkmoth (Laothoe populi)

Iron Prominent (Notodonta dromedarius)

 A rewilding project has been in place at the Knepp Estate for 13 years, based on a natural grazing regime in the old agricultural grasslands and the restoration of the River Adur floodplain to its natural function. This involves stepping back from hands-on land management, intervening as little as possible and letting nature dictate what happens. The idea is then to annually record the species and observe any of the changes over time in what turns up.

The wild Exmoor Ponies which freely roam the Knepp Estate

This exciting and long-term project contrasts greatly with our here method at Gatwick: our habitats are very small, fragmented and at times affected by airport operations, so we have to intervene in order to keep the ecosystems functioning. It has all been a great education for me on the different methods of wildlife conservation and countryside management. You can read more about Knepp Wildland project here www.knepp.co.uk