Tony, when I lived in Ca., outdoor cats would disappear on a regular basis due to the coyotes in the area.

Either the bobcat is telling your outdoor cat that "this is my area now" or it's a coyote that put it up the tree. If the bobcat wanted to kill your cat, they can climb trees too.......

www.hoosierpondpros.com

[Linked Image from lh6.ggpht.com]
http://www.pondboss.com/subscribe.asp?c=4
3/4 to 1 1/4 ac pond LMB, SMB, PS, BG, RES, CC, YP, Bardello BG, (RBT & Blue Tilapia - seasonal).