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The Ringing Scheme in Britain was 'hatched' in 1909, though
actually originated as two schemes: one run by British
Birds, instigated by the editor Harry Forbes Witherby
(right), and one at Aberdeen University, started by Arthur
Landsborough Thomson (left). A third scheme, organised by
Country Life magazine also started at this time,
but the rings were not uniquely numbered. The Aberdeen Scheme
ended during the First World War, and in the 1930s, following
the founding of the BTO, the British Birds scheme
was transferred to its current home. More details on the Aberdeen
Scheme can be found here.
In the early years of the Scheme, these pioneers set out
to answer some of the more basic biological questions of the
day. Where do our summer visitors spend the winter,
and where do our winter visitors breed? |
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| These
are still key questions for conservation, and ones for which
we now know the answer for many, but not all, species. But
at the time, migration routes were only known from observations
of birds on spring and autumn migration, and the legend of
Swallows spending the winter in pond bottoms was not long
dead. The first ring recovery of a Swallow in South Africa
then came in December 1912:
“That this Swallow breeding in the
far west of Europe should have reached so far
to the south-east of Africa as Natal, seems to me extraordinary.”
H F Witherby, British Birds Vol 6,
No 9 |
| Identifying
that Swallows spend the winter in South Africa (as the more
modern map on the right shows) was outstanding at the time,
and the importance of this shouldn’t be forgotten.
As noted by Witherby, these migrations are awe-inspiring
journeys. Even after 100 years, the wonder still exists; a
Sand Martin ringed at a Hampshire colony was recaught by the
same ringer the next winter in Morocco, only for the two to
be reunited again the next summer back at the same colony!
Distant recoveries also illustrate the prodigious, but regular,
journeys that are easy to forget. An Arctic Tern that flew
into a Japanese whaler off the Antarctic pack ice is the only
BTO-ringed bird to be found at a southern latitude higher
than the northern latitude at which it was ringed.
We’d be foolish to think we know it all now though,
and there are a whole suite of species for which we still
don’t have answers to these simple biological questions.
Wintering areas of declining species such as Swift and Pied
Flycatcher remain a mystery, and whilst we know so much about
Swallows, we know next to nothing about House Martins, with
just two recoveries south of the Sahara (in Senegal and Nigeria).
Migration patterns change as well, and can do so remarkably
quickly. We all know that Blackcaps winter around the Mediterranean,
but the late 1970s saw an increasing winter population in
Britain. Obviously these were our own birds choosing to stay
put and risk the winter weather… But ringing showed
that this was far from the truth, and that our wintering birds
were actually from the Continent. These were birds that had
migrated west instead of south and, with milder winters and
better food availability, this was a very successful strategy.
As the scheme grew (in age and size), then so did the record
ages recorded in birds. Very few wild birds reach anything
like their maximum potential age as there are too many factors
working against them – predators, accidents, weather,
disease, starvation and plain bad luck. Even so, the top five
longevities are staggering.
| Manx Shearwater |
51 years |
Bardsey Bird Observatory |
| Razorbill |
42 years |
Bardsey Bird Observatory |
| Fulmar |
41 years |
Eynhallow, Orkney |
| Pink-footed Goose |
39 years |
Tayside |
| Gannet |
37 years |
Bass Rock |

These longevity records are even more remarkable when you
consider the vast distances these birds will have covered
in their lifetimes. Our 51 year old Manx Shearwater from west
Wales (seen left at the tender age of 48) will have spent
51 winters off the coast of southern Argentina, covering 1.5
million kilometres just getting there and back!
But when we talk about longevity, we’re really talking
about extremes, which don't reflect the true picture for the
majority of birds. From a population point of view, and this
is the modern focus of the ringing scheme, we’re interested
in demographics; births and deaths, or in demography terms,
productivity and survival (the opposite of mortality). Collecting
this kind of information allows us to look in detail at what
is happening to populations. Population declines are often
caused by changes in just one part of a birds’ life,
be that fewer fledged chicks per brood, fewer nesting attempts
per season, lower survival of recently fledged chicks or overwinter
survival, for example. |