Visitors go to zoos to see the animals. That much is perfectly clear. What's also clear at points is that some of the animals have made a profession of being hard to see.
Not, obviously pink or orange flamingos, to be sure, but they're obviously playing in a different league from the tortoise at the top, who's clearly trying to convince us he's a member of a (literal) rock band. An impression that can only be enhanced by tucking his head out of the way.
But their resemblance to their background is not the only skill in their quivers; as the old tortoise and the hare story goes, they are slow but persistent. They have been known to slowly cover miles to get back to where they want to be; the zoo even knows of a 100-tortoise that scaled a ten-foot wall to get home.
Even when the background isn't as good a match, spots of different colors help to hide the shape and identity of animals.
This 'green' lizard, for instance, is actually a mix of colors; note how his tail blends in one way and his body another, allowing a fair blend to a variety of leaf, bark or earth backgrounds.
Same trick, but different colors for a different environment.
Black-throated monitor here, by the way. Notice that long, forked white tongue in the second shot? He was hoovering up insects with it...
Who? Me? A tortoise? You must be kidding. Nothing to look at, nothing at all, keep moving please. Go look at the iguana...
If it weren't for his lunch-time salad, this fellow could almost disappear.
Speaking of salad, here's an Asian leaf turtle, floating around disguised as, well...you guessed it. In the picture below him, if you look carefully, you can see a river terrapin. Just to the right of the little fish. And then a pair of turtles working hard at being green.
This is a gharial, sort of like an alligator drawn by a kindergarten artist and then brought to life.
And a real alligator, a Chinese one, just being a log...until it's time to eat.
Again with the multi-colors and the patterns; this one is a San Diego gopher snake. He's a real faker: all his fancy dress is copied from a rattlesnake, and when he's approached and feels threatened he shakes his tail back and forth like a rattler, although he's completely harmless.
And here we have a pair of rock-looking toads who frankly I wouldn't want to be near even if they were easy to spot.
And one last tortoise, out in the open and going nowhere. Ever. He's bronze!