EL Karstern 1955 Thamnophis elegans April 12 1/2 mi. S by SW of Court Center, Yosemite Valley Calif. Interesting case of a snake still active at quite low temperatures. While searching for Bufo boreas in pond I encountered the eye shine of a garter snake approximately 28-30" long. It was lying motionless in the water with but anterior 3 inches raised up. Dozens of Hyla were calling in this pond and the snake likely was preying on them but no buldge appeared in its stomach region. I wonder if the vibrations from the tree-frogs' vocal sacs might not be transmitted over the water surface to the body of the snake (?) The snake remained still for 5 minutes, probably purposely disturbed by my lens. I left the pond for about 10 minutes, my dead lens faded, and by the time I returned 20 minutes after leaving, the snake was rowling in sight. Its only observed movement had been swimming forward a foot just after I first spotted it. Water temp. 1" below pond surface 1 foot from edge where water 4" deep at 7:50 p.m. was 14.8°C. Air temp. 1" above water surface 8.0°C. and over dry grass 7.3°C. The warmer water undoubtedly enables this form to hunt at night under such conditions. I wonder how far it traveled out of water exposed to such low air temperature.