Spend any time watching garden birds and you’ll soon realise that there
is a great deal going on in your average garden. However, what you see is
merely scratching the surface of what is really happening and much remains hidden
from view because, to our eyes, most individuals of a given species look alike.
The handful of Blue Tits that you see daily at your hanging feeders may, in
reality, be many dozens of different individuals, which use your garden on a
daily, weekly or seasonal basis.
As a trained and licensed bird ringer, I have been able to appreciate
the numbers of individuals that may make regular use of a garden feeding
station. Even so, I still need to catch the birds regularly to discover which
individuals are still popping in for a feed. One way in which it is possible to
build up a more complete picture of the lives of individual birds is through
colour ringing, a technique by which licensed bird ringers fit birds with
unique combinations of coloured rings. Once fitted with such rings a bird can
be identified as an individual without the need to recapture it.
Colour ringing is best used for targeted projects, seeking to look in
detail at a population of birds within a given area. This might be at the scale
of the Blackbirds using a series of gardens in Holt (as is the case for one
Norfolk-based project) or it might be at the scale of Black-tailed Godwits
moving between Iceland and various sites in Britain and continental Europe
(research being carried out by staff at UEA).
Looking in detail at a particular population invariably adds to our
knowledge, revealing more about behaviour, ecology and survival. Colour ringing
of birds has, for example, been used to look at breeding behaviour,
highlighting which birds hold which territories and with whom they breed. At
the same time it can change your perception of the numbers of birds that make
up your ‘local’ population. Colour ringing of Great Spotted Woodpeckers at
Croxton, just on the edge of Thetford Forest, has been taking place over the
past six years. Some 63 different individuals have been colour ringed at the
feeding station in this time and resightings by the site’s owner have revealed
much about how these local birds are using the feeders. One female visited the
feeders almost every day for five years, while another was a regular visitor
for three years, only to disappear and then return two years later.
Colour ringing also enables members of the public to report any
colour-ringed birds that they may see. Simply contact the British Trust for
Ornithology’s ringing scheme (www.ring.ac) and let them know what you have seen
and where.
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