What’s the California newt’s lifespan?
Elizabeth O’Shea wrote to us in wondering about the California newt’s lifespan. It’s one of several salamanders we talked about in Land of the Salamander, our January 2013 cover story by David Rains Wallace.
I thought of this question myself on a hike on March 2, 2013, at the King-Swett Ranches, owned by the Solano Land Trust. Some rather uninviting stagnant pools amid large grassland areas turned out to be full of what looked very much like California newts. I was surprised because I usually associate newts with more permanent water bodies, while transient pools in grasslands seem more likely breeding pools for western toads, which rush through larval development and then retreat to uplands and underground burrows when the land dries out for the summer. (David Rains Wallace wrote about that for us way back in his 2003 feature A Leap of Faith.)
Poking around online, I found a site on genomics and aging with a page on newts. Apparently, a California newt in captivity can live almost 22 years!
I asked David Rains Wallace about this, and he said: “I’ve never seen any record or estimate of California newt longevity in the wild– or any other newt (or salamander) species, although the 20 year in captivity span seems general among both New and Old World newt species. Presumably Taricha would have a longevity boost in the wild by being inedible. Asian giant salamanders can live over 50 years in captivity.”
Wow, 50 years! (By the way, you can see those amazing giant salamanders over at the California Academy of Sciences’s Water Planet gallery.)
The story is surely much different in the wild. As a rule, a small critter like a newt would likely be food for lots of predators, but newts are incredibly toxic. Ukiah-based author Kate Marianchild told us about a finding that a single specimen of the closely related rough-skinned newt packed enough neurotoxin to kill 2000 people. Wow! But some garter snakes have developed resistance to the toxin and often hunt and eat newts. So predation from them, at least, will reduce average lifespan.
Another big factor is, well, us. Park managers at Tilden Regional Park in the Berkeley Hills famously close South Park Drive during newt mating season in winter to avoid carnage on the roads when the small amphibians make their way down to Wildcat Creek to breed. So in places where newts must cross human development to get to breeding areas, lifespan is likely shorter. That’s the kind of thing that makes habitat fragmentation such a problem.
Dan Rademacher is the editorial director at Bay Nature.