Palomar Observatory is home to a great variety of wildlife. Like our visiting astronomers, many of the animals are nocturnal. Deer are very common, but usually only sighted during dusk and during the night.
Once in a while I seen them during the daytime, as I did earlier today:
Can you spot the deer in the ferns? There were actually two of them, but only one was visible when I took this photo. Here's a cropped version showing the one that was visible: