Bird-ringing on the Minet site

Conservation and science go hand in hand; after all you can't begin to conserve an area until you know what is there to conserve. So at the Minet site a bird-ringing program has been started by A Rocha UK in conjunction with the Runnymede and Maple Cross Ringing Groups.

The site...

Wooded southern part of Minet site

The Minet site is a large area of grassland, hedgerows, woodland and scrub situated between Southall and Hayes in West London that has been designated as a Site of Nature Conservation Importance, Borough Grade 1. Yeading Brook, a tributary of the Thames, divides the site into two parts. The larger part of the site, situated north of the brook, is currently undergoing environmental enhancements prior to becoming the Minet Country Park. The smaller, southern, part is a long, thin strip of land between the Yeading Brook and the Paddington Branch of the Grand Union Canal. Here, mainly because the land is much higher, the area is quite different in character and ecology. The vegetation is dominated by scrub and young woodland, with some more open areas of weedy or marshy vegetation.

...and the birds

With these habitat types and the lower levels of human disturbance, the southern area of the site is a particularly good environment for several warbler species, such as Common Whitethroat, Blackcap and Garden Warbler. These birds spend the winter in Africa and southern Europe, migrating to the UK to breed where they need good cover and freedom from disturbance to nest. Because of the importance and interest of these birds a ringing program was started here in February 2002 and ringing took place on fourteen different dates on the British Waterways Board's property at Minet in 2002. A total of 452 birds of twenty-three species were ringed and in addition 150 retrapped birds - birds caught again after their initial ringing - were processed. No "controls" - birds that had been ringed outside the local area or in other countries - were caught. As this was the first year that ringing has taken place on this site, it is not possible to say whether any of the migratory birds, such as warblers, which were caught were returning to the same nesting sites. However, one bird, a Whitethroat, caught on the 16th of May, had been ringed as a juvenile in July 2001 at a nearby site (Feltham, West London). In between these two captures, this bird would have flown to sub-Saharan Africa, where it would have spent the winter, before flying back across a desert, two seas and a whole continent, to within a few miles of its birthplace.

Ringing breeding birds

Bird-ringing

As well as information about migration, ringing can tell us many things both about individual species and about how important particular sites are for birds that are breeding, on passage or over-wintering. So, for instance, from looking at the number of juvenile birds caught in May, June and July we can say whether a site is used for breeding by a particular species. For example, a total of sixty-five juveniles of three warbler species, Whitethroat, Blackcap and Chiffchaff, were caught on the Minet Site, throughout the 2002 breeding season. However only four juveniles of three other species - Lesser Whitethroat, Garden Warbler and Willow Warbler - were recorded. These figures suggest that the first three species were probably more successful in breeding at this site than the second three.

As well as the migratory warblers, good numbers of juveniles of several resident species were caught, including two species - Bullfinch and Song Thrush - which are priority species under the UK Biodiversity Action Plan and on the Joint Nature Conservation Committee's (JNCC) Red List of birds of High Conservation Concern in the UK. Several other species on this list breed in the adjacent Minet Country Park.

These first ringing results confirm that the southern part of the Minet site is a very valuable one for breeding birds, particularly those which nest in dense scrubby habitat and which are vulnerable to disturbance in more open sites. The hope is that the continuing ringing program will reveal much about the ecology of the site as well as adding to our knowledge of the biological, ecological and migration behaviour of the species that occur there.

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Ringing on the Minet site is coordinated by Colin Conroy and Dave Bookless. The British Waterways Board kindly allowed access to the site. For further information, contact Colin Conroy at colin.conroy@arocha.org