[Tweeters] Spotted Owl and Barred Owl hybrids

mgd at u.washington.edu mgd at u.washington.edu
Mon Dec 13 07:57:12 PST 2004


An article in the July 2004 issue of The Auk documents 47 known hybrids between these two species.

Kelly, Elizabeth G. and Eric D. Forsman.  2004.  Recent Records of Hybridization between Barred Owls (Strix varia) and Northern Spotted Owls (S. occidentalis caurina).  The Auk 121: 806-810.

Here are excerpts from the discussion section of the paper:

"In the period 1970-1999, we and other researchers searched for Northern Spotted Owls throughout most of the forested regions of the Pacific Northwest and banded > 9,000 Spotted Owls.  During the same period, Barred Owls were detected in or near many territories occupied by Spotted Owls.  The fact that so few hybrids were found during that period suggests that hybridization between Barred and Spotted Owls is a relatively rare event."

They caution that hybridization may be more common, however, due to the fact that backcrosses may be difficult to identify.

"Given the small number of F1 hybrids detected to date, there is little evidence that hybridization between Barred and Spotted Owls is a serious threat to either species."

"....hybridization is an interesting biological phenomenon that is probably inconsequential, compared with the real threat--direct competition between the two species for food and space."

Mike Donahue
Seattle






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