bizarre cat behavior

Question
My one year old cat has recently been exhibiting some odd behavior. She has always enjoyed looking out the windows but now only leaves them to eat or use the litter box.  The windows are not large enough to lie down so she stands in them ALL day.  She even sleeps in them standing up. This can't be very comfortable having to balance herself all day. On the rare occasion that she leaves the window she will balance on a chair leg and seems like she is avoiding walking on the ground. We can't figure out what brought about this weird behavior or how to help her. We take her out of the window to pet and hold her but as soon as you let her go she runs to the window. We would appreciate any insight you could give us.

Answer
I am sorry but I am not a cat behaviorist so I really can't answer this except to say at one year old it will probably pass. She must have seen some birds or squirrels in the tree so now she is fixated on that.

Give her some time and I am sure she will get bored of it. If not then call the vet and ask them for some suggestions.