Wandering Salamanders Choose Direct Route to Good Food

Old-growth redwood forest canopy arthropod prey base for arboreal wandering salamanders: A report prepared for the Save-the-Redwoods League

Wandering salamander. Photo by Dan Portik
Wandering salamander. Photo by Dan Portik

Wandering Salamanders (Aneides vagrans), in addition to dwelling on the ground, have been found in high-up patches of humus moss mats in trunk crotches, on limbs, under bark, and in the cracked and rotting wood of coast redwood trees. They may inhabit forest canopies, the researchers of this study speculate, because of a more profitable food resource available there.

Dr. Michal Camann, Karen Lamoncha, and Clinton Jones found that within the canopy the most abundant arthropods are mites and springtails, major prey items for salamanders, and unlike on the forest floor where mites make up the majority of arthropod populations, in the canopy springtails overwhelmingly outnumber mites.

This second finding provides a fine explanation for why wandering salamanders climb trees. Springtail adults are much larger than mites and much less sclerotized, or hardened by an outer shell. They are a softer, bulkier source of food that may have caused salamanders, over time, to follow their noses up.

An additional finding in the study was a harpacticoid copepod in the same humus moss patches inhabited by arthropods. This semi-aquatic crustacean, more closely related to a crab than any insect, was known to live in forest floor litter and in the gravel in streams, but had never been reported in the canopy. The researchers cannot explain how it got up there.

Though this study just scratches the surface of information to be gleaned from old-growth redwood canopies, these discoveries are clear indications of its ability to support complex life.

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