Having visited Living Desert today, I can confirm their summer opening hours are 8:00-1:30. I think this is totally reasonable for a number of reasons. First, it’s always interesting to see the high activity of animals (both captive and wild) early in the morning. Second, though the zoo is very spread out it’s not particularly huge in terms of animal collection, so I was done by around 10:30. Last, it was already 93 degrees when I got there and 106 by the time I left! The temperature slowly creeped up as the hours passed and I don’t blame the zoo for closing early in such intense heat. My only complaint is I had to wake up early to get to the zoo right at 8:00!