Harrington Airfield Report

 

Harrington Airfield Bird Ringing and Monitoring Report 2025.

 

Introduction

The area known as Harrington Airfield is a plateau of land between Lamport and Rothwell in rural Northamptonshire, which is mostly utilised for agricultural purposes. Historically the area was a military airbase in the Second World War and subsequently a missile base during the Cold War period. Concrete structures and tracks from this period still remain and form part of the habitat.

For the last forty-three years this area has become established as a birding area, i.e. a good site to observe and record both resident and migrant birds. The general recording area is west of the B576 to Draughton village and north to the area of Blueberry Copse and the museum. Birds that occur on the Draughton Pool between Draughton and Lamport and the pool between the main concrete track and the Brampton Valley Way (although rarely visited these days) are incorporated.

The migration of birds has fascinated naturalists and in the main is concentrated and easier to monitor in coastal locations in the UK. Observations over the years indicate that Harrington Airfield is something of a migration hotspot for birds both overflying the area and also dropping in and using the plateau as an area to rest and feed.

For the last eleven years permission has been granted for bird ringing to take place on-site. This is in order to further enhance the study of bird migration, ascertain population dynamics and the health of species and longevity of individual birds. During this period the bird ringing activity has been confined to the areas between the main concrete track and the B576 with most of the catching utilizing mist nets erected on poles and closely monitored.

Approximately 175  species of birds have been recorded at Harrington Airfield and during the forty-three years the species and numbers have changed significantly.

 

Key Breeding Species

The Willow Warbler is a small bird which breeds in Europe and migrates to Africa for the winter. During the last few decades the breeding population in the UK has shifted northwards with perhaps the majority of birds now in in northern England and Scotland. However at Harrington Airfield there is a colony of at least ten pairs associated with the scrubby areas around the bunkers. Many of the returning adults and juveniles have been ringed and despite the distances in their migration, site fidelity is very strong with individuals returning in successive years. This is potentially the largest and certainly the best monitored colony in Northamptonshire.

The Yellowhammer is a resident species associated with farmland, scrub and woodland edge throughout its range. In the UK it is a species showing a sharp decline in numbers. Winter stubble, supplementary feeding, low intensity agricultural practices and the provision of headlands, borders and similar providing invertebrate food for dependent young appear to be positive influences for this species which continues to be present on-site in reasonable numbers. Supplementary feeding between February and May, the ‘hunger gap’ months seems to be the critical factor locally.

The Skylark is a bird which thrives on low intensity agricultural land but somehow maintains reasonable numbers on less than pristine conditions is a familiar sight and sound at Harrington Airfield. The provision of winter stubble, generous borders and headlands, ‘Skylark plots’, invertebrate-rich substrate and a mosaic of different crops certainly assists this species.

The Grey Partridge is a surprisingly resilient and hardy species, it averages three breeding pairs per annum on-site. Although there may be influences from released birds for shooting purposes, in the main a small nucleus of wild birds stoically attempt to breed every year, with later breeding efforts sometimes leading to success. Present in the county in low numbers, Harrington is one of relatively few localised areas where a viable population remains.

 

Bird Ringing Data

All encounters with birds caught for ringing purposes are carefully catalogued and submitted to a national database maintained by the British Trust for Ornithology. This data is being continually analysed to establish the health and numbers of all species, and any recorded movements locally, nationally and even internationally and is a key indicator tool in assessing the risk to species associated with abundance, trends, breeding success, migration strategy and longevity.

Between 2014 and 2024, regular ringing sessions at Harrington Airfield have provided the opportunity to catch and ring over 8,000 birds, the majority being small to medium-sized passerines (songbirds and perching birds). In total  57  species have been captured and ringed as detailed below…

 

Species  Total     Barn Owl 2     Blackbird       248     Blackcap       568     Blue Tit       532     Brambling       143     Bullfinch       27     Buzzard       1     Chaffinch       323     Chiffchaff       202     Coal Tit       7     Dunnock       336     Fieldfare       101     Garden Warbler       26     Goldcrest       44     Goldfinch       413     Grasshopper Warbler       5     Great Spotted Woodpecker       3     Great Tit       207     Green Woodpecker       26     Greenfinch       84     Grey Wagtail 1       Jay       2     Kestrel       1     Kingfisher       1     Lesser Whitethroat       66     Linnet       747     Long-tailed Tit       121     Magpie       5     Marsh Tit       4     Meadow Pipit       289     Mistle Thrush       1     Redpoll (Lesser - cabaret)       18     Redstart       23     Redwing       919     Reed Bunting         193     Reed Warbler     13       Robin         184     Sedge Warbler         7     Song Thrush         83     Sparrowhawk         12     Spotted Flycatcher       1       Starling         8     Stonechat         1     Swallow         54     Tawny Owl       2       Tree Pipit       16     Tree Sparrow         15     Treecreeper       1       Wheatear       7     Whinchat       1     Whitethroat       527     Willow Warbler       439     Woodcock       2     Woodpigeon       1       Wren     138     Yellow Wagtail     2       Yellowhammer     804     Total     8007

 

The Redwing is a small, highly migratory member of the thrush family which does not breed locally but migrates in large numbers in the autumn as they move out of northern Europe and seek the comparative milder weather and provision of food provided in the UK and southern Europe. Significant berry crops, particularly Hawthorn and Blackthorn, ensures that Harrington is something of a food magnet during most autumns for this and other species. To date, more individuals of this species have been ringed at Harrington Airfield than any other, the majority during the months October – December.

The Yellowhammer is the second most encountered species and can be recorded at any time of the year. An unknown number of pairs breed on-site. Linnet and Common Whitethroat are also frequent species captured and ringed, both breeding on and close to the old airfield complex. The Common Whitethroat is a warbler species which also migrates to Africa, often choosing the acacia savanna of the Sahel region south of the Sahara Desert to winter.

 

Selected Ringing Recoveries

The following records are examples of recorded movements of birds that have either been ringed at Harrington Airfield or encountered there after being ringed elsewhere.

 

1.     A first year Redwing was ringed on 17^th October 2023 at Schiermonnikoog, Netherlands and caught again at Harrington Airfield on 17^th November 2023, 31 days later with the bird travelling 485km in a south-westerly direction;

2.     A Brambling was ringed at a site in Norfolk on 19^th January 2020 and caught again at Harrington Airfield on 11^th February 2022, 754 days later and 101km from where first ringed;

3.     A first year Brambling was ringed at Sore Merkeskog, Utsira, Rogaland, Norway on 4^th October 2021 and caught again at Harrington Airfield on 12^th December 2021, 69 days later and having travelled 847km in a south westerly direction;

4.     A first year male Fieldfare was ringed on 19^th October 2020 at Revtangen, Klepp, Rogaland, Norway and caught again at Harrington Airfield on 10^th November 2020, 22 days later and having travelled 812km in a south westerly direction;

5.     A first year Robin was ringed at the Power Station, Isle of Grain, Kent on 24^th October 2019 and caught at Harrington Airfield on 10^th November 2020, 383 days later. This is likely to have been a continental Robin wintering in the UK in successive years;

6.     A nestling Common Redstart was ringed on 2^nd June 2017 at Low Bramley Grange, North Yorkshire and caught in a mist net at Harrinton Airfield on 13^th August 2017, 72 days later and having travelled 208km in a south easterly direction on it’s way to African winter quarters;

7.     An adult male Reed Bunting was ringed on 2^nd November 2016 at Fishlake Meadows, Romsey, Hampshire and caught again at Harrington Airfield on 26^th June 2017, 235 days later and having travelled 162km in a north easterly direction;

8.     A first year female Blackcap was ringed at Harrington Airfield on 2^nd October 2023 and caught again at Plaisance, Saint-Froult, Charente-Maritime, France on 10^th October 2023, only eight days later with this small bird having travelled 721km in a southerly direction during that time;

9.     A first year Redwing was ringed at Harrington Airfield on 11^th December 2021 and on or about 11^th February 2023 was shot at Mata de Lobos, Guarda, Portugal, 427 days later with a distance of 1355km between sites;

10.   An adult male Blackbird was ringed at Harrington Airfield on 30^th December 2020 and caught again at Flamborough, East Yorkshire on 25^th June 2022, 541 days later with the bird moving 199km in a north easterly direction;

11.   A first year Redwing was ringed at Harrington Airfield on 12^th December 2021 and found dead as a road casualty on 20^th April 2022 at Bergen, Hordaland, Norway, 128 days later and with the bird travelling 952km in a north easterly direction;

12.   An adult male Reed Bunting was ringed at Harrington Airfield on 7^th September 2020 and caught again on 2^nd January 2021 at Glenmore Farm, Wick, Worcestershire, 117 days later and after travelling 86km in a south west direction;

13.   A first year Goldfinch was ringed at Harrington Airfield on 20^th October 2019 and was caught again on 3^rd December 2019 when at Bournonville, Pas-de-Calais, France, 44 days later after travelling 264km in a south east direction;

14.   A juvenile Goldfinch was ringed at Harrington Airfield on 20^th September 2015 and caught again on 5^th January 2016 at Chilworth, Surrey, 107 days later and having travelled 133km in a southerly direction.

 

Ringing Rides and Supplementary Feeding.

In order to use mist nets, ringing rides have been created and maintained in the scrubby areas near to the concrete bunkers with six permanent rides. They are kept clear of ground and side vegetation to permit the safe usage of mist nets. Occasionally other areas are utilized depending on methodology and species targeting. Monitored traps are deployed occasionally to catch specific species. During the course of ringing sessions, notices are deployed in an effort to dissuade people and their dogs from entering the ringing zone.

Supplementary bird feeding occurs in these rides and other spots from November to May in an effort to support species prone to starvation and support local birds during periods of harsh weather. In the main this is mixed seed and includes millet, sunflower, peanut granules, dried calciworms, oats, wheat, suet pellets and similar. When available linseed and oil seed rape is used to support dependent finches. All this food is provided as ground food without the provision of suspended feeders, hoppers etc.

 

Habitat

During the last forty years there has been a significant encroachment of scrub and small trees around the bunkers to the detriment of the rough grassland which supports a profusion of wild flowers including species of orchid. With Blackthorn and Hawthorn in particular growing over the grassland areas the numbers of scarce day-flying moths and butterflies have reduced. During the warmer months the ringing area is very much a dry site with the once established ponds and damp areas drying out. This potentially detracts from the general biodiversity of the site and reptiles and amphibians are now rarely encountered.

Heritage interest in the remnants of the airfield and missile launch-pads (referred to as bunkers) remains keen with quite a number of people visiting to look around. The USAAF memorial on the B576 layby is popular.

Crop rotation and crop types impacts on the wildlife and bird food crops and nectar strips are positive influences. Regenerative farming methods, overwintering stubble and environmental stewardship schemes provide further positive opportunities for most aspects of wildlife.

 

The Future

It is very much hoped that birdwatching and ringing can be maintained on-site and that on-going monitoring can continue to provide data appropriate for analysis. Habitat management and the use of the land around the bunkers will influence the birdlife and wildlife in general.

 

 

Neil McMahon

April 2025.