News of Newts

We’ve finally gotten some good precipitation here in Northern California, and with it all the wonders of the rainy season are beginning to emerge. One of my favorite delights of the rainy season is seeing the reappearance of another type of critters that has been hiding out beneath the forest duff through the dry season - The Newts! In California overall we have 4 species of Newt all of which are in the genus Taricha. Here in the Santa Cruz mountains we have the California Newt and California Rough-Skinned Newt. (1)

These two critters look and act extremely similarly, sporting bumpy orangey-brown backs with bright orange bellies.  They have striking green eyes which bug out of their heads in a cartoonish and charming manner.  The California Newt varies from the California Rough-Skinned Newt in how far these fish-like eyes stick out with the California Newt having slightly more exaggerated protruding eyes. (1) There are also a few minor differentiations to the colorations but that can be even harder to tell without one of each species nearby to compare! 

That bright orange belly thats flashed as they trod almost across the forest floor is not a false warning. The skin of these little newts is coated with deadly tetrodotoxin.  Instead of creating this toxin themselves, research indicates that it may be being created by bacteria living in the tissues of the newts and that the newts have developed an immunity in order to be able to use that very toxin as their defense! (2) 

Unfortunately for the newts, one of their local predators - the garter snake - has also come to evolve a defense against this toxin.  As the garter snakes evolve to keep up, the newts evolve to become stronger. Another interesting side effect of this relationship is that the garter snakes that have consumed these toxic newts can become poisonous themselves if eaten by other species.(3)  

There is so much more to learn about the Newts of the genus Taricha.  I hope to revisit them as I dive more into what we know of the wonders of this world. 

Do you have any favorite critters that only come out in the rainy weather?

1. Identifying Species of Pacific Newt: Genus Taricha.  CalHerps.com a guide to the reptiles and amphibians of california accessed: December 28, 2025. https://californiaherps.com/identification/salamandersid/newts.html

2. The skin microbiome facilitates adaptive tetrodotoxin production in poisonous newts. 2020, Vaelli et al. https://pubmed.ncbi.nlm.nih.gov/32254021/ 

3. A resistant predator and its toxic prey: persistence of newt toxin leads to poisonous (not venomous) snake. Becky L Williams 1, Edmund D Brodie Jr, Edmund D Brodie 3rd.  Accessed 12/28/2025 https://pubmed.ncbi.nlm.nih.gov/15609827/