The codes (4-letter codes not 6-letter) should be the same. The USFW codes
represents birds banded using bbl bands. These include some speices well outside
the AOU area. The AOU list covers all of North and Central America and
may include species that have never been banded with bbl bands.

There are other codes around around some of them are even (arguably) better.
Many show regional biases (all the local birds have the easiest codes), but
USFW has been around the longest.


>The recent subject of use of 4-letter codes left me with a question.
>
>Reference was made to the "USFS" codes, and an ftp address was provided
>where these codes can be obtained. I got them.
>
>There is also a list ("AOU91.TXT") of bird names and 4-letter
>(sometimes 5-character) codes available on the listserv where BIRDCHAT
>(another discussion list) resides.
>
>I compared the codes used on these two lists. The rough comparison is
>shown below. Following that are instructions on how to obtain these two
>lists of codes.
>
> # of
> List Name Codes
>-------------- -----
>on "AOU91.TXT" 1957
>on "USFS" 1300
>on both lists 787
>
>Now, these numbers are "rough" counts, since there are some duplicates
>on the "USFS" list where alternative abbreviated spellings of some bird
>names are included, and perhaps the two lists use different criteria
>for which species to include. But, the general trend is that the two
>lists contain different number of bird species, and each list contains
>birds that the other list does not contain. That's not surprising, I
>suppose. I did not check the codes with "match" to see if they all
>refer to the same bird species on the two lists; I did not check the
>codes which occurred on only one list to see if that species occurred
>on the other list (under a different code). I don't care enough about
>all this code stuff to manually read through the lists to make those
>analyses --I just did what was easy to do.... finding the
>codes-in-common.
>
>However, maybe some tweeter out there _does_ know what the differences
>mean, and which birders use which of the two lists when referring to one
>of those many species that do not share a common code? Any insights,
>tweeters?
>Peter
>- - - - - - -
>To get the AOU91.TXT list, send email to listserv at listserv.arizona.edu
>with this one-line message:
>get aou91.txt (size=500k
>
>To get the USFS list, use anonymous ftp to "ftp.im.nbs.gov" and change
>directories (cd) to "pub/data/cbc/trends" to find the file "aou.lis" which
>you can then GET.
>
>These two files, in spite of hinting to being the same AOU list, are not
>the same.
>
>

--
********************************
* Mike Patterson, Astoria, OR *
* mpatters at ednet1.osl.or.gov *
********************************