The AZA is merely a professional organization establishing guidelines–so they are not going to get into the nuances of exhibit design.

Zoo facilities have to also comply with local, state, and federal agency standards–USDA will inspect facilities and their guidelines are considered the _minimum_ standards.

The key word is minimum–it doesn’t mean adequate.

The AZA states that accredited facilities must meet those standards and you can find the latest here:
http://www.aza.org/Accreditation/Documents/AccredStandPol.pdf

Under the right circumstances (read high motivation) any animal can escape. In most cases it is usually due to human error such as failure to lock a gate or entering into the facility when the animal is actually in the exhibit.

I remember a day when I was going to enter into a bull elephants yard in a prominent zoo–he was supposed to be secured in his yard with an additional large pin as additional safety should the gate locks fail.

Since he was in musth–I double checked–and the pin was not in place despite my co-worker’s assurance that it was.

My point is that even if you have guidelines established, there is going to be human error.

I’ve also been on site when rain has washed silt down into an area of an exhibit shortening the height of the wall–and in this case, the lions had to be confined until the issue was corrected.

Most inspectors are going to eyeball things not measure. Many zoo employees become blind to changes in the exhibit or fail to do regular safety checks.

I did have a post with jumping examples and ranges here:
http://dianalguerrero.com/breaking_news_expert_comments.html

The report seems to do little more than to say that the SF Zoo had become complacently sloppy and needed to tidy up its operation. Based on my study of thousands of aviation accidents and reports, the cause of this incident goes a lot deeper than simple carelessness or neglect.

For example, the report never investigates or addresses just how high a wall a big cat can scale. Instead they merely recommend “…wall height should be closely re-examined and modified as necessary to prevent escape.”

The report seems to be addressing symptoms, not the disease, and I’m afraid that SF and other zoos won’t learn from it.