My experience with siskins both here and in the West (where they are widespread) leads me to believe that they focus on small cones.  They must visually key on cones as an indicator of seeds and don't have the strong beaks of other seed eaters, so they need small, weak cones to pry open.  In the northwest they focus on hemlocks and native red alders, while here in Ohio I've mostly seen them around white cedars and European alders.  Here in Columbus, I can pretty much guarantee siskins right now by finding a spot with a lot of the invasive European alders with cones.

______________________________________________________________________

Ohio-birds mailing list, a service of the Ohio Ornithological Society.
Our thanks to Miami University for hosting this mailing list.
Additional discussions can be found in our forums, at www.ohiobirds.org/forum/.

You can join or leave the list, or change your options, at:
http://listserv.muohio.edu/scripts/wa.exe?LIST=OHIO-BIRDS
Send questions or comments about the list to: [log in to unmask]