grp@Unify.com (Greg Pasquariello) (10/16/90)
Last night I received a newsletter from my old birding group in NJ, and there was an article about hybridization between Barred and Spotted Owls in the Pacific Northwest Apparently, this has happened in at least two cases, one in Washington, and one in Oregon. This has caused some concern among biologists that the more aggressive Barred Owl might threaten the species status of the Spotted Owl. There was a reference to a newspaper article, which I will post tomorrow (Sorry, I forgot the newsletter today). In the meantime, does anyone know any more about this? -- -Greg Pasquariello grp@unify.com
sandee@sun16.scri.fsu.edu (Daan Sandee) (10/17/90)
In article <1990Oct16.085100@Unify.com> grp@Unify.com (Greg Pasquariello) writes: >Last night I received a newsletter from my old birding group >in NJ, and there was an article about hybridization >between Barred and Spotted Owls in the Pacific Northwest >Apparently, this has happened in at least two cases, one in >Washington, and one in Oregon. This has caused some concern >among biologists that the more aggressive Barred Owl might >threaten the species status of the Spotted Owl. > >-Greg Pasquariello grp@unify.com I've read the same thing somewhere but I haven't been able to find where. As I remember, the Barred Owl is invading California, and hybridizing with Spotted Owl occasionally. As it is less specialized in choice of habitat, it is going to win out wherever they meet. If that trend continues, the A.O.U. will have to lump them, according to their criterium - successful hybridiz- ation occurs frequently when they meet. I haven't heard about Arizona (Southern Spotted Owl). As for concern : there is no evidence (apparently) of human involvement. So it appears to be a natural process. Of course, it will give concern to people who like the greatest possible diversity in Nature, as expressed by the number of species, and to birders who see their life lists threatened ... As I read it (wherever it was that I read it), Manuel Lujan was reported to have reacted brightly about the possibility of the Northern Spotted Owl being degraded to a subspecies. But he was wrong : it already IS a subspecies. And changing the name to Northern Sparred Owl is not going to make it less threatened ... (Just a vicious rumor, I suppose. About the smile on Lujan's face, I mean). Daan Sandee sandee@sun16.scri.fsu.edu Supercomputer Computations Research Institute Florida State University, Tallahassee, FL 32306-4052 (904) 644-7045
grp@Unify.com (Greg Pasquariello) (10/18/90)
In article <1138@sun13.scri.fsu.edu>, sandee@sun16.scri.fsu.edu (Daan Sandee) writes: > In article <1990Oct16.085100@Unify.com> grp@Unify.com (Greg Pasquariello) writes: > >Last night I received a newsletter from my old birding group > >in NJ, and there was an article about hybridization > >between Barred and Spotted Owls in the Pacific Northwest > >Apparently, this has happened in at least two cases, one in > >Washington, and one in Oregon. This has caused some concern > >among biologists that the more aggressive Barred Owl might > >threaten the species status of the Spotted Owl. > > > >-Greg Pasquariello grp@unify.com > > I've read the same thing somewhere but I haven't been able to find where. > As I remember, the Barred Owl is invading California, and hybridizing with > Spotted Owl occasionally. As it is less specialized in choice of habitat, it > is going to win out wherever they meet. If that trend continues, the A.O.U. > will have to lump them, according to their criterium - successful hybridiz- > ation occurs frequently when they meet. I haven't heard about Arizona > (Southern Spotted Owl). Brought my newsletter today. The article appeared in the New York Times, August 14, 1990. The two confirmed hybrids were at Mount Baker, in the northern cascades in Wash., and east of Medford, about 600 miles from Mt Baker, and in Southwestern Oregon. > As for concern : there is no evidence (apparently) of human involvement. > So it appears to be a natural process. Actually, it is felt that human involvement is _exactly_ why the hybridizations occur. Logging of the Spotted Owl's old growth habitat has allowed the Barred Owl access to the area, as it is much more adaptable to the cut-over area. > > Daan Sandee sandee@sun16.scri.fsu.edu > Supercomputer Computations Research Institute > Florida State University, Tallahassee, FL 32306-4052 (904) 644-7045 -- -Greg Pasquariello grp@unify.com
bob@delphi.uchicago.edu (Robert S. Lewis, Jr.) (10/18/90)
In article <1138@sun13.scri.fsu.edu> sandee@sun16.scri.fsu.edu (Daan Sandee) writes: >As for concern : there is no evidence (apparently) of human involvement. >So it appears to be a natural process. Of course, the radical changes in the nation's environment brought about by human settlement and development may have a lot to do with the spread of the Barred Owl. As forests are chopped up into small parcels, species that adapt well to the edges of forests begin to penetrate regions which in the past were inaccessible to them. Hence the strategy of preserving a species by preserving small areas of its natural habitat does not always work well. Many birds that are spreading, are doing so because of changes in the environment brought about by humans. The cowbird, for instance, has been expanding East since Europeans came to America, since it adapts well to an environment where small woodlands are intermixed with open areas. This is because the cowbird is a parasitical nester that parasitizes woodland species, but prefers to feed in open areas. Before Europeans cleared much of the Eastern forest, cowbirds were apparently much less common, being restricted to forest borders. As clearings in the forest opened up cowbirds moved in. This was good for cowbirds, but terrible for warblers, which used to be able to protect themselves from cowbird paratisism by breeding deep in the forest. Now cowbirds can penetrate the smaller forests to the forest's heart, leaving no safe havens for small woodland breeders.