Subject: [Tweeters] Identifying Tundra Peregrines
Date: Fri Nov 29 12:12:03 PST 2019
From: Bud Anderson - falconresearch at

Among the 20 or so races of peregrine worldwide, the tundra peregrine
(Falco peregrinus tundrius) was the last to be officially recognized by

Professor Clayton White, now retired from BYU, first described it in his
Ph. D. dissertation back around 1968.

The other "tundra" peregrine (F.p. calidus), occurs in Eurasia, and to my
knowledge, has never been confirmed in Washington.

Trying to call the subspecies of individual peregrines in WA is always fun
but is far more difficult and challenging than you might have been lead to

Certainly there are some individual birds that can be assigned a
subspecific identity. Obviously all eastern Washington and some western WA
breeding pairs are anatums (F.p. anatum). Many of our coastal pairs are
classic Peale's peregrines (F.p. pealei), so both of these resident
subspecies are known to breed here. The tundra peregrine does not.

However, it does migrate through WA during both spring and fall. Several
banded migrant tundra falcons from AK have been recovered in WA on

For example, the first ever WA peregrine band recovery, a nestling banded
on the Colville River in AK in the 1950s by none other than the late Tom
Cade, was beaten to death by a logger during fall, as it sat on a Snow
Goose it had just killed.

Times were different back then.

During our winter months, most peregrine experts are quite hesitant to
positively call subspecies of both adults and juveniles. You probably
should be too.

Here is the problem with identifying tundra peregrines in the field.

First off, with few exceptions, the vast majority are wintering in Central
and South America. They are the most highly migratory peregrine in the
world and are outdone among all falcons only by the Amur Falcon (Falco
amurensis) in total distances traveled.

Second, most birders, having rightfully looked at the paintings/photos of
juvenile peregrines in the field guides, learn that a light head, light
supercilium line and white auricular, always indicate a tundra peregrine.
They often do. But it is more complicated than that.

Anatum peregrines and, surprisingly, many Peales Falcons can also show
these same features.

Clayton White pointed out early on that approximately 25% of Queen
Charlotte Island Peales juveniles had light heads and superciliums that
were similar to tundra peregrines.

Clayton and Steve Herman, both peregrine experts, were the first people to
mentor me into always using caution about calling peregrine subspecies in
the field. Good advice.

Subsequently, among the several hundred WA nestling peregrines that Ed
Deal, Martin Muller and I have banded over the many years in the San Juan
Islands, Seattle and Tacoma, several of these known origin, color-banded
birds have exhibited these features, incuding the supercilium line and
light head.

I have seen young birds hatched in downtown Seattle that many inexperienced
birders would definitely call tundra peregrines.

A good friend prompted me to address this issue because of the recent Fir
Island reports of a juvenile tundra falcon. In looking at several photos of
this bird, I can understand the inclination to ID it as such but I think
Ryan is correct in classifying it as unconfirmed.

So, go have fun, challenge yourselves, and keep learning but in my opinion,
it is probably best to not positively call peregrine subspecies in winter
unless you can read a band on the bird and positively know its natal origin.
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