Garter Snake, approx. 2-2.5 ft long. Alternating stripes of yellowish-green, black, and brown. Rather sluggish at 62°F. We encouraged him off the trail before the bike riders came along.
California Red-sided Garter Snake (Thamnophis sirtalis ssp. infernalis)
Endemic in California, US: native and occurs nowhere else.
Reddish-brown patches behind eye are distinctive for this species.
Red on sides and head. Upper labials. Chin shields. Confirmed in range map:
http://californiaherps.com/snakes/pages/t.s.infernalis.html
Identifying Gartersnakes
http://www.californiaherps.com/identification/snakesid/gartersnakes.id.html
"all species of garter snake are often found in and around the water, and sometimes aquatics are found a long distance from any water, so the location is not a reliable way to ID them. To properly ID a garter in this area you would need a clear shot of the head scales" per INat acastelein.
Link to my confirmed Garter Snake observations, for comparison:
Diablo Range Garter Snake (Thamnophis atratus ssp. zaxanthus) https://www.inaturalist.org/observations/166000829
Coast Garter Snake (Thamnophis elegans ssp. terrestris) https://www.inaturalist.org/observations/110554649
California Red-sided Garter Snake (Thamnophis sirtalis ssp. infernalis) https://www.inaturalist.org/observations/99493314
Key to California Gartersnakes— A side-by-side comparison chart:
http://www.californiaherps.com/identification/snakesid/gartersnakeskey.html
Garter Snakes are in Colubrid Snakes (Colubridae) family. Most colubrids are not venomous, or have venom that is not known to be harmful to humans, and are mostly harmless. Some colubrids are described as opisthoglyphous "rear-fanged," meaning they have elongated, grooved teeth located in the back of their upper jaws.
Snakes: https://californiaherps.com/snakes/snakesmaps.html
Guide to Amphibians and Reptiles of California: https://californiaherps.com
Reptile Database (41 species of Garter Snakes worldwide as of 2/12/24)
https://reptile-database.reptarium.cz/search?search=garter+snakes&submit=Search
CA tiger salamander with vape for scale.
This marten was likely up at 10,900ft/3300m to hunt pikas, but when I stumbled along it became very curious about me. I was able to snap photos for about 8 minutes, then moved on to photograph the flock of rosy finches that was half dosing off while observing the marten. I wasn't able to observe any predation, but may have heard a couple distant screams.
Trail 21, Jasper Ridge Biological Preserve, a few meters from west end of Searsville Dam. About 7.5 inches long. Photos 3,4 by Alice Cummings