Biodiversity Gatwick: Rings of Power

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!