California Owls Fly North, Mix With Oregon Species

The flight of immigrants from California to Oregon doesn’t just include high-tech transplants and retirees. Spotted owls seem to be headed north too.

Scientists examining the genetic makeup of owls from as far north as the Siuslaw National Forest west of Corvallis found that about 13% were California spotted owls.

It’s not clear why the scarcer California owls, native to the Sierra Nevada and Southern California mountains, are flying north.

And scientists aren’t sure what interbreeding will mean for the genetic makeup of northern owls.

“It’s somewhat confusing because we’re not seeing owls here that look very different from northern spotted owls,” said Eric Forsman, a spotted-owl biologist with the U.S. Forest Service in Corvallis and an author of the studies.

If the proportions seen in the study carry through to the rest of the nearly 10,000 northern spotted owls in the Northwest, about 1,000 may belong to another subspecies.

Conservation groups have asked that the California owl get the same Endangered Species Act safeguards as the northern spotted owl, meaning that the Northwest may find a second protected spotted owl in its forests.

Researchers suspect the northern migration began fairly recently, because the owls remain distinguishable through their DNA. Some mixing between the subspecies is normal.

The findings, however, could revive an argument that the owls are similar enough to be combined into a single subspecies.

Scientists are trying to gauge the differences among three subspecies of spotted owls: northern, California and Mexican.

They found the Mexican spotted owl of the Four Corners states clearly distinct, but they had a more difficult time identifying the other two subspecies.

“We were not expecting there to be this much mixing,” said Susan Haig, a U.S. Geological Survey conservation genetics specialist and lead author of the studies.

But almost as many California spotted owls appeared to be in the Olympics, Cascades, Coast Range and Klamath region of Oregon and Washington as in California.

Haig said there is no evidence of the northern spotted owl moving into California.