Technology

LOOK AT CHECK CODES and BEST READ RINGS AT END of this page

For the individual identification of birds many marking (ringing) methods have been used. Most common methods are combinations of colour rings, colour rings with characters, multi-coloured rings, leg flags, neck collars, wing tags, nasal tags and saddles. Most of these marks are designed to be read at field from distance by telescopes and binoculars. Look at some examples of marking systems, ring types and coding in web-pages >>

http://www.lpo-anjou.org/baguage/code_BTO.htm and http://www.pwrc.usgs.gov/BBL/homepage/aboutaux.htm and http://www.holmer.nl/Colourrings.htm

There are three different types of common plastic rings: overlapped, spiral and butt-end rings. In spiral rings the plastic strip is rolled at least two times around the leg. In overlapped types the ring is closed with small overlap. All these rings should be clued in order to prevent rings to get stuck. Some are closed also with snap-fits. Rivets are also used to ensure some large rings.

The codes are normally engraved to read rings. Typically numbers and common letters are used in codes. These characters can be in different positions. These should be marked down when reading the rings, because they can be a part of the code of check-code. Some additional small figures, like lines or dots, can also be used. (Look at the marking systems in www-pages above.)

I am very interested to develop new type of read rings. I have made myself totally over 200 000 read rings (for many species, to over 20 countries) and ringed about 13 000 gulls with read rings and read personally over 80 000 day-reads. I make limited amount of read rings as a hobby also for foreign projects (but not in summer). I worked for many years (retired since 2009) as a lecturer of plastic materials and technology in University of Applied Sciences (earlier North Karelia Polytechnic).

Click on the thumbnail for a larger version!!

Created with
© Jeff Waldock, 2004
Saved syyskuu 30, 2004 16:26

CHECK CODES (look also at the pictures in ROLLING, not well edited in a hurry)

My strong opinion is that check codes ought to be used always if possible.

The incorrect reads (mistakes) spoil all the data. The use of check codes filters the incorrect data away and gives a sight to the proportion of the incorrect reads.

The false reads are very common see How ro read. However a lot of read mistakes happen in your brains. It is very common to turn the order of characters upside down. For instance you see codes like C12A or ABC, but write them down as C21A or CBA or A21C. These false are very common if rings are easy to read upside down ie. you have symmetric (looking) codes like A00H >H00V or H96X > X96H. These should not to be used at all.

Check codes can be used in many levels. The lowest level is the parity check (Modula 2). Modula is an algorithmic formula that gives a number from division by named number. At least most of the common computer languages have it. Better checks are possible with higher levels of Modula (like in our personal codes or in bank account numbers). In Finland we have used Modula 15 or Modula 11. That is very effective. It prevents actually all the false reads. And in some situations one can calculate the whole code even if the check mark of its situation is observed even if some of the main character are missing (cannot be read). Typically this is common while reading the code from photos.

Examples of the can be seen in these photos. In the Finnish 5 character Herring Gulls rings (argentatus) Cxxxx there exists a powerful check code (an extra character). Actually only 3 characters (out of 4 plus country code "C") are enough to identify the bird. Some Finnish LBBG (fuscus) rings have a Modula 4 check code. But in 2005 I made rings with 4-bit underlining hyphen check codes (look at the red fuscus rings in the pics). They have Modula 15, which is very effective, but a bit difficult to read. However, I have already now found it useful when checking some codes from digital photos. I have also tested in 2005 some new rings for my Herring Gulls with small additional marks (spots or hyphen or vertical lines at different level/heights).

Now I am moving to easier observed marks like (large) spots (look at the pics) between the main characters. These additional marks are not obligatory, but very useful. Many European projects will have this type of check codes at least in the read rings made by me.

Please, have a look at the examples in these pics. The check codes are VERY useful, use them !!!!

Note:

The red CnQn read rings with white codes (where Q is X, Y or Z and n a number, 240 ones) belong into my own special year 2005 Finnish Herring Gull project and the reads must be sent directly to me (not to the FRC). They have no metal rings. These rings have different additional marks, which are partly essential in order to define the individuals. This is due to the testing of these additional check marks at the field.