Luke, I'm not sure how far you deeply you want to delve in bird slang.
You'll probably find the commonly used ones, e.g. sky rat, butterbutt,
Bony, etc., fairly easily, and all you have to do is look in some books
that list alternate names to compile a rather substantial list. But there
are presumably hundreds or thousands of cases where individual little
groups (with group size as few as 2) of birders come up with pet names for
birds. I don't do this much any more, but years ago in Miami I remember we
came up with some names that we used regularly.

PD for House Sparrow (from Passer domesticus)
Nowl for Barn Owl and Dowl for Barred Owl, to avoid confusion in the names

Don't forget the use of the 4-letter acronyms. I don't know how widespread
this is, but some of us who recorded seabirds on censuses by their 4-letter
codes started calling Marbled Murrelet MAMUs, Pigeon Guillemots PIGUs, etc.
Interestingly, some observers record seabirds by 4-letter codes made from
their scientific names, but I don't know if anyone ever shortens these to
endearing little abbreviations.

How many words in English (or any other language) can be made from 4-letter
acronyms of either common or scientific names?

Dennis Paulson, Director phone 206-756-3798
Slater Museum of Natural History fax 206-756-3352
University of Puget Sound e-mail dpaulson at ups.edu
Tacoma, WA 98416