[CT Birds] Red Crossbills by ear

[Nick Bonomo]

Hi Clay,

Happy New Year. Nice sighting of so many crossbills in Westbrook! Just
wanted to give a few words about the different types and their call
notes. This year's invasion has consisted mainly of type 4 birds,
according to the birds identified so far. Of the birds at Hammonasset
and East Shore park from a few weeks ago, all were type 4 except for
one or two type 3. I was told second-hand that analysis of Red
Crossbills in New Jersey resulted in several type 4 and a single type
2.

In my observations of the crossbills at Hammo, where they were also
present in nice-sized flocks, the variety of calls that the birds were
giving at one time was quite impressive. At any given time, a few of
the birds could be giving flight calls, others giving a variety of
softer calls while feeding, and one bird even broke out into song (a
finchy warble)! The way to ID the different types is by hearing their
flight calls, which can be given while perched, especially right
before and after taking flight.

Basically, type 4 flight calls are short, pure-toned, and rising. By
contrast, type 3's give rougher and slightly descending flight calls.
Type 2's are also slightly descending, not buzzy. Type 1's are short
and descending. They are difficult to ID without computer analysis,
except by those with extensive prior experience. Type 4s, being the
only rising call, is probably the easiest to ID by ear.

The way you described the fly-bys as making buzzy calls, they may not
have been the previously-documented type 4's. Very interesting, thanks
for sharing with us. If time permits I will try to get to Westbrook
and record those birds, if they stick around.

Nick


Nick Bonomo
Orange, CT