diablo range or coast garter snake adult swimming in a pond

francisco bay area pleasanton ridge regional park nonvenomous water beautiful one foraging moving agile striped widespread common gray natural pets colorful pattern nature carnivorous thamnophis camouflage colubrids endemic day adult alameda county california motion black yellow stripes animals wild wildlife elegans western terrestrial gartersnake terrestris garter snake coast aquatic swimming creepy nonpoisonous venomous reptilia slither reptile fauna diablo range