Once again I touch this subject because I got so many responses as
MMD postings as well as private emails.  My many thanks to everybody for
all the hints (especially literature) and advice on how to proceed with
my project.  Today I would like to summarize what I received:

There are quite a lot of books and articles describing singing bird
automatons, describing who, when and where they were made and how they
work in principle.  On the other hand, it seems as if nowhere is
described the design of the whistles with practical rules, experience
and design parameters.

When Julie Porter in MMD 110326 mentions, "As for the pipes, any good
book on physics will have a section on resonance theory," then this is
correct as long as the word "theory" is stressed.  The gap between this
theory and the skills to make a real pipe, sounding exactly as wished,
is close to the difference between "Theory of Colors" by Johann Wolfgang
von Goethe [1810] and the skills to create an artistic painting!

For the practical design of many different types of organ pipes, two
classical standards do exist:

1. Dom Bedos De Celles: L'art du facteur d'orgues, 1766,
   [The Art of the Organ-Builder], and

2. Karl Bormann: Orgel und Spieluhrenbau, kommentierte Aufzeichnung des
   Orgel- und Musikwerkmachers Ignaz Bruder (1829) und die Entwicklung
   der Walzenorgel, 1968, [Making organs and organ clocks, commented
   notes of the organ and music work maker Ignaz Bruder (1829) and the
   development of the barrel organ].

To get more information about a detailed example of the latter, go to
http://www.mmdigest.com/Archives/Digests/201001/2010.01.24.03.html  or to
http://www.lulu.com/product/paperback/how-to-make-tune-and-voice-reedpipes/6284039 

Conclusion: For the _bird whistle_ or _bird pipe_ no comparable
literature on practical experience seems to exist.

Greetings from Germany,
Christian Greinacher