Signs, Signs, Everywhere There Are SIgns

We just returned from a fun side trip to Death Valley (2 hours from our hotel in Las Vegas). We toured all over the place looking at the mountains and then some other mountains and we finally finished up with seeing... more mountains. We followed signs that informed us of "Points of Interests" that could definitely be debated as "in the eye of the beholder".
That was yesterday and my friend Suzi wanted to see the sun rise over one of these mountains this morning. The problem was, we didn't know what time sun rise was. The people we asked the night before said they're "night people and the only time they see the sun rise is on the way home from an especially good party, and they hadn't been to such a party since the summer.
Well, the alarm went off in our room at 2:12 a.m. Apparently, the maid who cleaned the room prior to our arrival thought that would be a funny joke on the next residents. Suzi tried to turn off the alarm and un-wittingly, she also changed the time to an hour earlier. I awakened at 5 a.m. and showered. Just as I was finishing dressing, Susan comes around the corner looking kinda irritated. She informed me that her watch confirmed the fact that is was 4:15 a.m., not 5:15 a.m.

Anyway, we got to the sunrise mountain and climbed 600 yards up to a very cold vantage point and we didn't need to fight anyone over the best viewing location.
Susan wanted to get here early to get a jump on the crowds of people who had come up with the same grand idea that we (Suzi) had. Oh, wait ~ there WERE no crowds! We were the only ones up there, with teeth chattering and frozen tears on our faces. Not ONE other person decided to get up to help us greet the morning.
OK, so it was pretty, I must admit.

Back to driving to more "points of interests"...what I don't get is the signs that are posted every 4 miles for various animal crossings. How do these burros, long-horn sheep, roadrunner birds, kangaroo rats and turtles know exactly where they are to cross? Do they read signs? Did ONE person maybe on ONE day happen to see that particular species amble across the road so they decided to plant a sign at that spot?
I really can't imagine the turtle being able to look up that far to realize that maybe he is 30 yards off his "official crosswalk". What is his incentive to use that particular lane? Will he get a ticket if he moves 1/4 of a mile around the curve?

In Ohio I see the signs for Deer Crossing all the time. I have never ONCE seen a doe waiting at that sign to spring over to the other side of the street.

I think I'll put a sign up in front of my house on the street showing "Ant crossing" just to see if anyone slows down.