Monday, 9 January 2023

Thursday, 15 December 2022

Aerodome of the Dragon

Of all the UK airports, could Gatwick be the one with the highest diversity of Odonata (dragonflies and damselflies)? I imagine strong contenders might be London Ashford Airport (Lydd) in Kent, or even Heathrow Airport in Surrey... I am boldly throwing down the gauntlet to those who wish to challenge us for the dragon throne. If you are a naturalist who has been observing dragonflies on or near other airports, let us know in the comments of this blogpost!

Willow Emerald Damselfly Chalcolestes viridis

Facing a warming climate, many dragonfly and damselfly species are changing their geographic range, with new species moving further inland from warmer coastal areas and others arriving from the continent. So far, we have recorded 23 different species of around our land-locked, but low-lying and pretty wet airport. That is six fewer than the best-performing Sussex Wildlife Trust nature reserve Rye Harbour (29 species). The nearby Knepp Wildlands site hit 23 species in around 2019, but they have surely passed that total now.  

Bob Foreman from the Sussex Biodiversity Record Centre kindly provided me with the top ten league table for Sussex Wildlife Trust reserves. As you can see, we might be on par with the Ebernoe reserve for the moment:

1. Rye Harbour                       29
2. Burton Mill Pond                25
3. Woods Mill                         25
4. Iping Common                    24
5. Old Lodge                           24
6. Ebernoe                               23
7. Amberley Wildbrooks          22
8. Peveensey Levels                19
9. Filsham Reedbed                19
10. Waltham Brooks                 17

This summer just past I was repeating a baseline survey of all the waterways previously surveyed around Gatwick during 2013. We have gained a few new ponds since that last baseline, so I was really looking forward to getting stuck in and seeing how fortunes may have changed for our dragons. Results were a bit of a mixed bag, with only 20 different species observed (I was missing Ruddy Darter Sympetrum sanguineum, Golden-ringed Dragonfly Cordulegaster boltonii and Red-eyed Damselfly Erythromma najas). The only new record for the site has been Small Red-eyed Damselfly, and nothing particularly rare or unusual turned up except for a tantalising glimpse of Brilliant Emerald Dragonfly Somatochlora metallica (although there were plenty of similar-looking Downy Emerald Dragonflies about).

Here are a few of my highlights from the 2022 field season:

Downy Emerald Dragonfly Cordulia aenea

White-legged Damselfly Platycnemis pennipes

Four-spotted Chaser Libellula quadrimaculata

Small Red-eyed Damselfly Erythromma viridulum

Black-tailed Skimmer Orthetrum cancellatum

Broad-bodied Chaser Libellula depressa looking the worse for wear

Our Top 3 performing waterbodies during 2022:

The upstream section of the River Mole (16 species)

Land East Pond 2 (the Brilliant and Downy Emerald pond) 13 species

The northern bank of Pond F, the reservoir at the South Terminal (11 species)

Gatwick's current dragonfly list:



Monday, 19 September 2022

Rings of Power

When visiting ornithologist Jon Middleton remarked the airport biodiversity sites could be worth trialling for bird ringing, I thought that would be cool, wish I knew some bird ringers... It turned out I already did, I work with a few of them, I should have asked sooner, and they've been happy to help out! 

Wheatear Oenanthe oenanthe, caught and ringed under license in Gatwick Airport's North West Zone 

The North West Zone at Gatwick is a mosaic of scrub, outgrown hedgerows and floodplain meadow, maturing nicely for the past 20+ years (all created during the River Mole diversion in the year 2000), with a block of ancient woodland in the mix. Gatwick has the added interesting element of urban and brownfield habitats at the interface of natural ones, resulting in a highly diverse mix of species, including small migrating birds visiting the sites at different times of the year.

The edge of Gatwick's North West Zone



Scrub management with volunteers from the Gatwick Greenspace Partnership

Monitoring birds has been integral to Gatwick's Biodiversity Action Plan since it began in 2012. Birds are a great indicator of ecosystem health, but are also particularly important here in the context of the airport and aircraft safety. Data from our ecological surveys helps us to understand what species are using our sites and how they are faring, so that we can better target habitat works to conserve them. 

A metal BTO ring being placed on the tarsus (the area between the ankle and knee) of a Great Tit Parus major 

Bird ringing is a very intensive survey method and is therefore treated very sensitively. It involves catching birds in order to take biological measurements, placing a uniquely coded ring on the bird's leg for future identification, and then re-releasing back where they were found. Obviously this can be stressful to the bird, and welfare must always come first in this work. The British Trust for Ornithology (BTO) are the overseers of the UK Bird Ringing Scheme and the rigorous licencing procedure. Training to become a fully permitted bird ringer takes a very long time, involving many hours of work and brutally early starts in the mornings! 

Trainee bird ringers at Gatwick with Jon Middleton (right)

Information gathered from bird ringing is extremely eye-opening, such as the different species and numbers using a site, which is not necessarily picked up during our standard field-observation bird surveys. Historically, ringing work has helped to confirm where certain birds go from the UK during winter (as far as sub-Saharan Africa!!).  These days we are learning more about different migration routes, changing distributions of species and ongoing impacts from habitat loss, hunting and climate change. It is important that we collect data from more common species as well as those already known to be in decline, as we can't be sure how any species may fare in the future. 

Examples of other information collected through the ringing scheme:
  • Ages
  • Survival rates*
  • Health/condition
  • Breeding success (by the year ratio of captured youngsters to adults)
  • Dispersal locations and distances
  • Phenology (life cycle timings)
  • Population trends

* Advances in statistical techniques have allowed survival to be calculated from recaptures of previously ringed birds. The more birds ringed, the better the chance of recovering data, all of which will be vitally important for future bird conservation. 


Airport security officer Trevor receives a demonstration from licensed bird ringer Stuart Card

One of the recent successes for our biodiversity project has been the arrival of breeding Nightingales at Gatwick, with the first confirmed modern record in 2016.  A male Nightingale ringed at the Knepp Wildlands project during August 2020 was found holding a breeding territory at Gatwick during 2021, and 'Dave' has been heard singing away again during summer of 2022.

One of two Nightingales Luscinia megarhynchos ringed at Gatwick this year. July 2022

I am hugely grateful to Jon, Stuart and Jake for donating their valuable time and energy in getting this exciting new project underway. Below are some highlights of what we have found so far, and we hope to see more species added to the list as time goes on. Watch this space!

Black Redstart Phoenicurus ochruros (male), a rare breeding species in the UK. September 2022

 
Marsh Tit Poecile palustris, September 2022

Sedge Warbler Acrocephalus schoenobaenus, September 2022

Wheatear Oenanthe oenanthe, August 2022

Redstart Phoenicurus phoenicurus, September 2022

Ringed species at Gatwick so far:

  • Black Redstart Phoenicurus ochruros (Amber listed, Schedule 1)
  • Blackbird Turdus merula
  • Blackcap Sylvia atricapilla
  • Blue Tit Cyanistes caeruleus
  • Bullfinch Pyrrhula pyrrhula (Amber listed)
  • Chiffchaff Phylloscopus collybita
  • Dunnock Prunella modularis (Amber listed)
  • Great Tit Parus major
  • Green Woodpecker Picus viridis
  • Goldcrest Regulus regulus
  • Goldfinch Carduelis carduelis
  • Lesser Whitethroat Curruca curruca
  • Long-tailed Tit Aegithalos caudatus
  • Marsh Tit Poecile palustris (Red listed)
  • Nightingale Luscinia megarhynchos (Red listed)
  • Redstart Phoenicurus phoenicurus (Amber listed)
  • Reed Warbler Acrocephalus scirpaceus
  • Robin Erithacus rubecula
  • Sedge Warbler Acrocephalus schoenobaenus (Amber listed)
  • Song Thrush Turdus philomelos (Amber listed)
  • Willow Warbler Phylloscopus trochilus (Amber listed)
  • Wheatear Oenanthe oenanthe (Amber listed)
  • Whitethroat Curruca communis (Amber listed)
  • Wren Troglodytes troglodytes (Amber listed)

Rings around the world: More on the Nightingales found at Gatwick Airport:

Tuesday, 15 March 2022

Gatwick Airport's Annual Biodiversity Review 2021

We are pleased to publish Gatwick Airport's Biodiversity Annual Review for 2021, containing more species highlights and conserved habitats than ever before! It was a significant year for Nightingales which are featured on the front cover, as well as pages 26, 34 and 36 of the report.

A huge thank you again to everyone who contributed their time and efforts for the project. 

Gatwick Airport Annual Biodiversity Review 2021



Monday, 13 December 2021

Small mammals of Gatwick

Recently published research by the Mammal Society has revealed some very worrying news; the UK's small mammals are not faring as well as we thought. Species previously not known to be at risk, including Weasels, Stoats and even our seemingly ubiquitous voles and shrews, are suffering long-term declines and are in need of conservation action. It is now estimated that 1 in 4 species in the UK are in real danger from extinction.

We have known for decades that UK landscapes are highly pressured, nature-depleted places in which to live, but the scale of the problem is still coming to light. Small mammals are important, and usually abundant, parts of natural ecosystems. Their loss will impact our habitat dynamics, ecosystem stability and populations of other wildlife which depend on them. 

Publication by the Mammal Society

Intensive management or development of land leading to the disappearance of long, naturalistic areas of vegetation which these species need has taken its toll. We are fortunate that buffer land around an airport can provide resources for a wide range of small mammals: Harvest Mice, Hazel Dormice, Weasels, Stoats, Common and Pygmy Shrews, Field and Bank Voles, Yellow-necked and Wood Mice have all been confirmed on our sites. We have also identified opportunities outside of these areas, with a new road-verge management regime providing those all important long-grass areas.

I have been playing with some new lens attachments for trail cameras, targeting better close-ups of small wildlife. I set up a Browning trail camera on an old log pile within our best scrub and grassland, which looked to be a hub of activity due to all the niches and crevices. It is always fascinating to observe different species interacting with each other. After trawling through a lot of footage, the results are in; I can officially and scientifically state that all small mammal species are Very Cute.

If you happen to own or manage a very manicured piece of grassland, then perhaps think about setting aside some longer grass areas, particularly at the base of shrubs, trees and hedgerows. You could just mow your patch once a year in early spring, before the wildflower species get going. Collecting up the cuttings and leaving in a pile in a corner is very beneficial to insects, mammals and reptiles too.

Thanks for reading... here are a few Gatwick Bank Voles, mice and shrews for your enjoyment.

Thursday, 1 July 2021

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