Epoch: Endemic invertebrates of Empire Cave

No one knows why Cave Gulch, on the edge of the University of California Santa Cruz campus, is so heavily blessed with endemic species - species that are found nowhere else in the world.

But the cave-studded gulch encompasses the entire global range of no fewer than six species. All six are invertebrates specially adapted to the limestone caves of this minor gulch. I'm not sure, and to my knowledge no one is, why none of these species occurs elsewhere. In fact, at least two of them are found exclusively in Empire Cave (or Porter Cave as it's known to UCSC students), the largest cave in the drainage. I've visited this little jewel a couple times, and here is what I've seen with regards to rare species.

The Empire Cave spider (Meta dolloff) spins its feeble orb web in the twilight area of the cave in order to feed on the insects that live there. These spiders look somewhat like giant black widows, except for their splotched abdomens¹.

The yellow-eyed ensatina (Ensatina eschscholtzii xanthoptica) is a subspecies of the ensatina salamander. The yellow-eyeds are endemic to central California. Their range is highlighted in yellow on this map from California Herps (my go-to source for information on reptiles and amphibians). The ensatinas are adorable little salamanders that are members of the family Plethodontidae - lungless salamanders which breathe through their skin, which has to be constantly kept moist². It is this fact which makes it so strange for wandering salamanders (Aneides vagrans) to be found hundreds of feet high in California's redwood canopy. When scientists discovered them living happily there, they wondered how on earth the wandering salamanders, which also belong to the Plethodontid family, could stay moist in the tops of the tallest trees in the world. It turns out that coast redwoods, Sequoia sempervirens, are giant "aquifers aloft." They hold huge amounts of water in deep soil mats, in addition to the water they pump of from their roots and comb from the fog to feed themselves³.

Anyway, back to yellow-eyed ensatinas. These beautiful little guys have grooves up and down their bodies, can be territorial, and are able to drop their tails to distract predators. During breeding season (or rather seasons, as yellow-eyed ensatinas breed during Fall and Spring and sometimes Winter), males rub their bodies and heads against females in an elaborate courtship ritual. Finally they drop a sperm capsule on the ground, which the female picks up with her cloaca and keeps until she decides the time is ripe to fertilize it. At the end of the season, the female lays the eggs under bark, logs, or rocks (or maybe in a cave?) and lays three to 25 eggs. She stays with them until they hatch.

My friends and I have found yellow-eyed ensatinas both above- and belowground. We have not spotted any of the other five known endemics, but I will tell you about them if we do.