One should always start with the smallest and work up in size. The smaller owls that would respond become intimidated when a larger owl is calling. All of these lure calls should be used very sparingly.
Those of us engaged in the Saw-whet banding network have documented many cases of predation/attempted predation by larger owls looking for a meal. While Saw-whets won't call during migration, they do respond and the bigger guys appear to know that. Screech, Barred Long-eared and Great Horned -all caught while looking for that free meal. Best, John -- John and Sue Gregoire Field Ornithologists Kestrel Haven Avian Migration Observatory 5373 Fitzgerald Road Burdett,NY 14818-9626 Website: http://www.empacc.net/~kestrelhaven/ "Conserve and Create Habitat" -- Cayugabirds-L List Info: http://www.NortheastBirding.com/CayugabirdsWELCOME http://www.NortheastBirding.com/CayugabirdsRULES ARCHIVES: 1) http://www.mail-archive.com/cayugabirds-l@cornell.edu/maillist.html 2) http://birdingonthe.net/mailinglists/CAYU.html 3) http://www.surfbirds.com/birdingmail/Group/Cayugabirds Please submit your observations to eBird: http://ebird.org/content/ebird/ --