From Newsgroup: talk.origins

https://www.science.org/content/article/how-much-killing-will-it-take-save-spotted-owl

Spotted owls are losing ground in the Pacific Northwest, so they have
started killing the Barred owls that are outcompeting the Spotted species.

They claim that they are two different species, but they can interbreed
and they know that at some time in the past that it was the spotted
species that made it to the Midwest. During the glacial periods the
Rocky mountains separate the two species, but during the interglacials
the ice recedes and pine forests grow up across Canada, and produces a
highway in which the two species collide and can interbreed. Spotted
owl genetics can be found in the Eastern Barred owl populations.
Apparently, during a previous interglacial it was the spotted owl that
crossed the Canadian pine forests to interact with the Barred species.
This time it is the other way around, and the Barred owl is an effective competitor and is forcing the Spotted species out of the territory that
it reclaimed once the glaciers had receded. The Spotted owls are being
pushed back to their Southern habitat where they survived the last
glacial period.

It looks like this interglacial period it is going to be the Barred owl
that leaves their genetics in the Pacific Northwest, but the the current Barred owl population seems to be better adapted to the interglacial
period and may take over the Northwest territory of the Spotted owl and
could even drive the species to extinction if they continue to spread to
the Southern territory.

My take is that they should not be killing the Barred owl. This type of species replacement has been happening since life originated on this
planet. Why would you want to mess with the situation and end up nurse
maids to a species that would have gone extinct and been replaced by a
species better adapted to the existing environment. You will have to
baby sit the Spotted owl from now on, unless you step in and improve the species so that it can compete, and then you'd likely have to do the
same thing for the Barred species.

What they may be preventing is the type of hybridization that occurred
during a previous glacial period where the Spotted and Barred genetics
mixed among the Barred owls of the East and produced a species that can
better survive the interglacial periods. Previously the mixing occurred
in the East among the Barred owl population, but in the next glacial
period the hybridizations incorporation of hybrid genetics would occur
in the West among the spotted owls.

Ron Okimoto

Ron Okimoto

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