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About the Euring Databank index
This page provides
information about the types of data that are included in the EURING
databank (EDB) and about how the index was constructed.
Contents
Euring
Data Bank
The Euring Data
Bank holds copies of recovery records from bird ringing schemes
throughout Europe. In the past, the emphasis was on birds ringed
and later recovered dead. However, for many purposes such as survival
analyses and studies of natal dispersal, recaptures or resightings
of living birds are just as valuable. Recently, the number of live
records has overtaken the number dead records.
There is, necessarily, always a time lag
between a bird being recovered and the processing of that recovery
being completed at a ringing centre. Some schemes are able to send
their latest recovery data set very regularly to the EDB, some other
schemes send very large batches at long intervals. We estimate that
the data bank now holds about two-thirds of recoveries from the
last decade and over 90% of all recoveries since ringing began in
Europe.
Details of the coding scheme that is
used for these data can be found here.
EURING welcomes applications to analyse
data from the EDB. Details of how to apply for data can be found
here.
Contents of the EDB index
This index will be
updated approximately annually. At the time of the most recent update
of the index, there were recovery histories for nearly 3 million
ringed birds and, of these, many have multiple encounter records.
Pairs of maps are provided for all species
for which there exists at least one recovery. One map shows the
recovery location of birds and the other the ringing locations of
these birds. Maps have a resolution of 5° by 5° and the
symbols indicating numbers of individuals in each block are logarithmically
scaled. There is a similar pair of maps for each species where there
exists at least one live recapture or resighting.
In addition to the information for each species
there are four summary tables, two for the dead recoveries and two
for the live recaptures. In each case there is one table giving
the number of records per scheme per decade (live
and dead). The tabulation per
decade is based on the date of recovery or recapture.
All species with any live
records, together with the number of records per decade, are tabulated
here. Similarly, all species with any dead
recoveries are tabulated here.
Types of data held in the EDB
The quality of the
data in the EDB is variable and for the purpose of making this index,
only a very limited amount of checking has been performed (see below).
The basic unit for constructing this index is the EDB record. One
such record describes one encounter with a bird which may be its
first encounter (ringing event) or a subsequent encounter (recovery,
recapture or resighting). Here, two types of subsequent records
are considered:
- Encounters with living birds, that have
been identified through either recapture, or reading the ring
or other unique marks from a distance. In these cases, there can
be multiple records per individual (White Stork is an example
with many records per individual). The first record for an individual
is the ringing record and all other records are subsequent encounters.
- Encounters with dead birds. Associated
with each recovery record there is a record with the ringing details
of that individual. Cases of later reports of the same ring are
ignored. There can thus be only one record of a bird recovered
dead per individual.
Ringing data are only included for individuals
that are later encountered again, alive or dead. It is possible
that an individual is encountered alive one or more times and is
later encountered dead. In that case, the data for this individual
will appear once on the map of ringing locations for birds later
recovered dead and it will appear once on the map with the recovery
locations. The same individual will appear as often as it has been
reported alive on the map of recapture/resighting locations (at
the same or different localities) but it will also appear on the
map of ringing locations for birds later reported alive as often
as it has been reported alive. One extreme example are the data
for the Spoonbill for which there are many more resightings than
individuals that have been ringed.
Maps of ringing and finding locations
The first step towards
map construction was a tabulation of all records for each species
in 5° by 5° blocks, both for the ringing and for the finding
locations and for live and dead recoveries.
Summary tables
Each pair of maps is
accompanied by two tables
The first table gives an overview of the
number of records by decade. This tabulation is based on the year
of recovery or recapture. All records referring to data before 1940
have been grouped. The data for the last few years are, neccessarily,
incomplete and will increase when updates arrive from schemes.
The second table gives an overview of the
schemes that have contributed any encounter records for the species.
Again, the numbers are blocked in decades.
Cautionary notes
- Name changes in schemes.
This is an index of the data in the EURING Data Bank. The names
of schemes appear in the index as they are on the records in the
EDB, which in turn corresponds to what is written on the rings.
Several schemes have changed names when the countries changed
names. For example LIK (Lithuania, Kaunas) was previously SUK
(Soviet Union, Kaunas). In some cases schemes have recoded old
records - for example DDH (Hiddensee, East Germany) has become
DEH (Hiddensee, Germany). In some other cases, older records will
not have been recoded.
- Species and subspecies.
For a number of species, there are separate codes for subspecies
as well as a species code. In this index all subspecies have been
combined into the single species pages. The use of subspecies
is not consistent among schemes and over time. Some problems may
arise if former subspecies have been elevated to species status
and given a full species code.
- Schemes and locations. Data
are classified under schemes, which are the schemes that issued
the ring. Within Europe, birds are normally ringed with rings
of the scheme responsible for that area, but there have been exceptions
and European rings have also been used in Africa and Asia. Thus,
recovery data or recapture data in Africa can also arise from
locally ringed birds. The EDB does not routinely collect records
of birds ringed in Africa but some records involving the use of
European rings in Africa have been included.
- Updates. This index was
made on all data in the EURING Data Bank in September 2003. Updates
of maps and tables may be expected to be made every year or two.
- Deleted records and totals.
The purpose of this index is to give an overview of the data available
in the EDB. Some incomplete records have been disregarded in some
tabulations, but not in others. This may lead to small discrepancies
in numbers between tables or between the information per species
and the tables. The most common problem is incomplete spatial
co-ordinates. The proportion of problematic records is in the
order of 2 per 10 000.
EURING is particularly grateful to the Netherlands
Institute for Ecological Research which hosted the EDB from 1977
to 2005.
The EDB is currently hosted by the British Trust for Ornithology.
Contributors
We are grateful to all of the Ringing
Schemes who have contributed to the EDB, without whose
efforts this invaluable European dataset would not be available.
These schemes in turn are dependent on large numbers of ringers
(most of whom are volunteers), birdwatchers and members of the public
for the collection of data. We thank all of these people for their
contributions.
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