Paul P asked:

Years ago I watched a documentary, probably on Nova, about a desert Oasis that over time dried up. As the water slowly evaporated the animals who shared the area had to live closer and closer. I was a kid when I first saw it but I remember thinking that the footage took place over a long period of time (months at least). By the end only the crocodiles were left (they eventually died also). I’ve been trying to figure out the name of the show or episode but haven’t’ had any luck.