The Daily Bucket is a regular feature of the Backyard Science group. It is a place where we share our observations about the natural world. Whether we note the spring migrating birds or the first buds on your trees, we are building a resource to learn more about the patterns of nature and how they may be changing. Everyone is welcome to contribute! Just tell us what you are seeing in your backyard or wherever you are roaming and approximately where your observations come from.I've come to regard the Pacific Northwest (in particular, the NE corner of the Olympic Peninsula of WA) as having few really hostile critters. But then, what should Mr. Watt encounter along the trail? A poisonous newt (no, not the political one)!
Their range extends south to Santa Cruz, California and north to Alaska, primarily west of the Cascade mountains. Other members of the Taricha genus include the California newt (T.
torosa) and the Red-bellied newt (T. rivularis). They are the only land-dwelling animals producing significant levels of tetrodotoxin.
There is an interesting relationship between this newt and its main predator, the common garter snake which has developed some resistance to the poison. The snake's resistance level and the newt's production of toxin have co-evolved toward a kind of balance. Newts with "just enough" toxin survive to pass on their ability to make the toxin because garter snakes will vomit up live newts up to 85 minutes after eating them. Newts with too much toxin paralyze the snake before getting regurgitated - a lose/lose situation for all concerned. Newts with too little, of course, become the snake's meal.
The toxicity and resistance levels differ in different regions. Apparently on Vancouver Island, for example, both newt and snake seem to have negotiated a balance such that both poison amounts and resistance to the poison are lower there than in other regions. There seems to be a benefit to both sides in requiring less energy to deal with producing/resisting the poison. In Oregon, on the other hand, the populations have evolved toward higher levels.
So, that's our recent discovery of a hostile critter lurking in our neck of the woods.
What's happening where you are?