I'll go at least one more time for the cub's antics and will bring the Canon Rebel XT + zoom to get better larger images.
  Used the little Canon SX260 again.   Did take shots of other animals but later on that...

  Here's a Flickr photography discussion about trying to get clear pictures thru' the zoo's pexiglass windows (no meshing in tiger exhibit).

LARGE shot at Flickr.  I've added new shots of San Francisco Zoo's tiger cub, at 6 months old and later at Flickr until I can put them here later.  There, they're viewable in large thumbnails so that you don't need to click through for larger photos to get a sense of the visits.

To see the PBase.co images that are 1024 pixels wide (or larger) for the thumbnails below, *click* on 'ORIGINAL' option below the first photo that comes up after you click on a thumbnail; otherwise, and that setting will stay for the session.  It defaults to 800 pixels wide.