By popular demand, here’s a natural extension of my first post: an index to the Red Crossbill call types on some of the cuts in the Macaulay Library collection.  First, a couple of introductory notes and caveats:

1. Typing Red Crossbills from recordings is not an exact science.  It’s not difficult if the bird is giving actual flight calls, but if the bird is singing, things can get confusing in a hurry, because the songs of Red Crossbills frequently contain strings of repeated sounds that resemble flight calls, but are really just notes in the song.  These song notes might be variations on the bird’s own flight call type, or they might somewhat resemble another flight call type, or they might just be something else entirely.   The point is that a solid identification to type requires a good string of call notes outside the context of song — and not all recordings provide such.
2. In addition to song and flight calls, crossbills also give other calls, most notably the excitement calls (or “toops”) and the juvenile begging calls (or “chittoos”).  The excitement calls do vary from type to type.  It is not known whether the begging calls do too.  To avoid confusion, I’ve limited the examples in this post to cuts of flight calls only.

All identifications to type have been corroborated by Matt Young at Cornell.  Thanks for your help, Matt!

Type 1

#138304	New York	8/6/06
#138305	New York	8/6/06
#138306	New York	8/6/06
#138312	New York	8/6/06
#138320	New York	8/6/06
#138323	New York	8/6/06

Type 2

#39869	Oregon	9/4/85
#44960	Oregon	6/18/89
#48897	California	6/13/90
#49601	California	6/13/90
#84567	California	6/10/97
#99362	California	6/4/92
#111103	Oregon	4/20/90
#111104	Oregon	4/20/90
#119400	California	5/29/01
#120416	California	6/5/02
#120423	California	6/7/02

Type 3

#94205

Maryland

12/28/1997

(with Type 10)

Type 4

#58167

Alberta

5/23/61

Type 10

Groth’s (1993) monograph identified eight Red Crossbill types in North America.  Benkman (1999) identified a ninth type endemic to the South Hills of Idaho.  Ken Irwin (unpubl.) has proposed that there is a tenth type, which was actually recorded by Groth, but lumped with Type 4.  Ironically, my Colorado Birds article mentions this call type as a variant of Type 4 (the variant without the initial downslur).    Right now, expert opinions vary somewhat on whether this variant is actually separate from Type 4, but whatever it is, it seems to be relatively common and widespread, or at least widely wandering.

#94201	Maryland	12/28/97
#94205	Maryland	12/28/97	(with Type 3)
#112167	Maine	7/16/98
#130478	New York	5/17/98

I hope this post is helpful to those who want to try to sort these types out for themselves.  In conjunction with the Red Crossbill cuts on Xeno-Canto, the Macaulay cuts should get you off to a good start!