Rock squirrels use large rocks as lookouts to scan for predators or other dangers, warning their kin with loud whistles or chirps that can be confused with bird calls. They can be seen all along the riverside walk trail... they are very cute .. not scared of coming close to the visitors.. they give poses to the camera.. but the park advisory says they can bite!! These squirrels have been known to get into backpacks, lunch pails, and trash cans, and to steal food right out of visitors' hands. .... I saw a rock squirrel climb into a baby stroller.. Luckily he escaped when the baby’s parents started panicking.... these guys are getting very fat by eating the food fed by visitors.. the park had posted an obese and a lean squirrel photos and advises not to feed them....