At 08:52 5/3/98 PST, you wrote:
>I remember a class with Rocky Gutierrez (yes, another misspelling by
>the Sacramento Bee) where he told us that there was some belief that
>Barred Owls and Spotted Owls may actually be the same species and
>were just not separated long enough to finalize the evolution into
>two distinct species, much like Northern Flickers. Has anyone heard
>of further research in this area that either confirms or denies this
>belief?
>jw
>Jane Westervelt
>Moscow, ID
>
>

I just checked the Birds of North America account for the Spotted
Owl (#179) written by Rocky Gutierrez, A. B. Franklin, and W.S. Lahaye. As
of 1995, there were 5 records of Barred Owl x Northern Spotted Owl hybirds
and 1 record of a California Spotted Owl x Barred Owl cross. There is also
a record of one of the hybrids pairing with a Barred Owl and creating 5
young backcrosses. They finish the section by stating that the extent of
hybridization is unknown but it is assumed to be low. If you want to go
directly to the source, it is: Hammer, et al. 1994. Hybridization between
Barred and Spotted Owls. Auk 111: 487-492.
The Spotted Owl is probably the most studied of all of the owls; yet
only six instances of hybridization have been recorded. Most ornithologists
have no problem considering these birds separate species. In fact, there is
discussion that the Spotted Owl may be split into three species. There are
definitely three distinct subspecies: the Northern Spotted Owl, the
California Spotted Owl and Mexican Spotted Owl.
In birds, the presence of hybrids between two species doesn't
necessarily make them one species. Birds have an amazing capacity to
hybridize. They can even hybridize across genera, and even across families.
Birds are very closely related genetically so if two species mate, they can
usually produce viable young.
It is the amount and spread of hybridization that determines whether
species will be combined together or kept separate. The hybridization zone
for most species or species pairs such as the Norther Flicker, Western and
Eastern Meadowlark, Lazuli and Indigo Bunting, Spotted and Eastern Towhee,
Bullock's and Baltimore Orioles, occurs in the middle of the Great Plains
(Texas, Oklahoma, Kansas, Nebraska and the Dakotas). In the case of the
Northern Flickers, the hybrids have spread out from the hybridization zone
and can be found almost across the country (we have hybrids here in Pullman)
so they are considered one species. In most of the other species, the
hybridization zone has remained narrow for many decades and the hybrids
don't seem to be spreading so they are separate species.
Mammoloigists have it much easier. If two "species" hybridize and
produce viable offspring, they are really the same species. Mammals have
been around for a much longer time than birds and they have greater genetic
distance than birds. The genetic distance between two species of mammals is
generally equal to that between two *families* of birds.

Hope that helps!

Deb Beutler
Department of Zoology
P.O. Box 644236
Washington State Univerisity
Pullman, Whitman Co., WA
dbeutler at wsunix.wsu.edu