I have become the proud adoptive care-giver of some Rough Skinned Newts. Adopted not so much by the newts; they didn’t have much of a choice. A couple of kids had caught them, showed and gave them to me. Now I know that I should have shouted: “put them back where you found them” or done that myself, but as a biologist and scientist I always ask some questions first before I let rip… and that was how I found out the water had been changed, which changes everything.

actually, that reminds me of my youngest son finding a baby garter snake a few months ago and being told to put it back where he found it. “But”, he vehemently protested,” if I do that and close the door as you told me to, it will get cut in half!” Apparently he had spotted it slithering into the house through the, as always here, left-open front door… Check and mate! He has that from his mother...

back to my newts though.. so the water had been changed. All over the world amphibians, including frogs, toads and salamanders (which is what newts are), succumb to a lethal disease known as Chytridiomycosis, caused by a fungus running riot, the Chytrid fungus Batrachochytrium dendrobatidis (or Bd for short), which is rapidly infecting water and land. Not knowing whether “my” newts already have it, whether it is already present in where they came from, or whether it is present in the changed water, the last thing I should do is to introduce the disease into somewhere it hasn’t reached yet. So no “put them back where you found them”… I am stuck with them. Much to my not-so-secret delight, but scientifically rock solid and responsible… which has given me a much valued opportunity to observe them in their daily activities and habits at close hand for unlimited time. And I am absolutely fascinated by them.

Rough Skinned Newts (Taricha granulosa) are pretty well unique to the West Coast of North America and one of only three species in the Taricha genus, all of which are from the Pacific west (US and Canada) Coast. Our newts have, as their name suggests, a rough “granular” skin, most of the time anyway, darkish brown top and sides and a bright orange belly which is suggested says: don’t eat- I am toxic. Well toxic it certainly is; Rough Skinned Newts have the same toxin as the Puffer fish, what we now call tetrodotoxin but which used to be named, in their honour, tarichatoxin. Which then must make it, at the very least size for size, just about the most toxic animal on earth. The amount of toxin in one small newt skin is enough to kill 20,000 mice or 31 humans..

well… not quite. This is where it gets interesting. The only somewhat active predator of the Rough Skinned Newt and at least to an extent immune to the toxin, is the garter snake (Thamnophis elegans), and when he or she catches one, will hang on to it for a bit to determine whether the catch is too toxic or not and spit it out if it is. This led to the suggestion that our newt has evolved increasing levels of toxicity to defend itself against in particular garter snakes to the extent that it “beats” the immunity of that reptile and continues to beat it as garter snake immunity increases. However it doesn’t appear to be as simple as that. The toxicity level between different populations of Rough Skinned Newts varies enormously, apparently by as much as 1000 times, which is good news for about 1980 mice and all humans then… And it has been reported that on Vancouver Island at least in some populations the toxin is absent, even though Vancouver Island most certainly is not short of garter snakes; in fact it has three species of them...

remember that earlier I said Rough Skinned Newts have the toxin; I did not say they produce it. It has been sub-contracted out and the toxin is produced for them by particular bacteria living in and under the skin. Therefore the toxicity level is closely related to the activity of these bacteria or the population level of them (which in bacteria-speak is more or less the same thing). And the bacteria activity or population level is of course determined by what the newt has to offer, which can vary for a number of reasons, such as health, environmental conditions and so on. So far we haven’t solved any of that puzzle yet, so the proposed evolutionary progression of the Rough Skinned Newt towards a “design” level of toxicity beating the garter snake is purely speculative, although elegant and romantic, but rather dubious.

and of course my adopted newts will not solve that puzzle either; I haven’t got enough of them to pull apart and experiment but, above all, I enjoy watching them too much to waste them. Plenty else to learn there still. Such as how they feed…..

feeding newts was a massive learning curve. Both for me and for them! According to all available literature, Rough Skinned Newts will only eat live and moving stuff, such as insect larvae, snails, worms, tadpoles etc.. And if you haven’t got any, waving a piece of meat held by forceps in front of their nose so that they THINK it is alive works. HUH!!!!!! I wonder what wag came up with that one.. No luck. Trial and error did it in the end, with lots of fun on the way.

as there was no time to carefully plan and prepare, after all they arrived unannounced and unexpectedly, I had to do some quick thinking when I prepared their new residence. So I decided that my main feed was going to be worms, of which I have plenty and especially the species they reputedly like, and would try some very small fish for variety in their diet as well as exercise. So I bought and introduced 12 “white cloud minnows”. Now, some 6 or so weeks later, I have over 20 white cloud minnows: the original 12 + offspring. Not that my newts weren’t interested in them; they most definitely were. Every now and then one of them would spot one and go in hot pursuit (well.. newt-like hot pursuit; everything is relative..) with the same result every time: ever so close to catching it another minnow appeared in their field of view, stopping them dead in their tracks…. “Which one to catch? Oh choices, choices….!!!” So the minnows were a dead loss. From a food perspective anyway; they do a wonderful job keeping the place clean though so they are definitely an asset. And they have the wonderful habit of pointing the newts to where there is food they can get at at leisure.., the worms.

the first few days I collected some worms and placed them right in front of the newts. Wriggling like mad, as they hate being in water, so no mistake guys.. these ARE alive and you cant miss them! The newts were invariably fascinated, and watched the worms dig themselves into the gravel. Every time. With a half baked and invariably failing attempt to snap at the last bit of worm as it disappeared underground.

so I introduced a wide, steep sided glass dish to place the worms in and overcome the problem of digging in. Put half a dozen of them in together and they will try and dig themselves into each other, creating an ever moving, wriggling ball of worms. Easy pickings and plenty of time to do it in.

again, the newts were (and still are) fascinated by that. They will sit for hours watching it.. from ground level at the side of the dish and trying to get at them, bumping into the glass. The newts would hang in the plants carefully placed above and over the dish for the purpose, watching it all, and then, instead of simply reaching down and take a bite, swim off to the side of the dish, planning the attack from there. This went on for two or three days. It was not until the minnows consistently swam over the sides and into the dish to eat whatever it was that came with the worms (and clean them up), that one of them caught on and tried the same. Eventually followed by the others. Success! Of a kind anyway; they still do exactly the same except it doesn’t take days for them to make that move anymore, more like a few hours. From what I have seen and am seeing, the conclusion seems inevitable that “critical habitat” for Rough Skinned Newts consists of somewhere where there is an absolute over-abundance of potential food items that they can bump into, purely by accident, and that move or respond slowly enough for the newt to make up its mind as to whether to have ago and taste it or not.

despite that, Rough Skinned Newts are not exactly in short supply here on the Sunshine Coast or elsewhere. You don’t have to be that lucky, if you know where and when to look and have a little bit of an eye for it, to spot groups of literally hundreds of them in the water, all of them doing more or less the same…. nothing much. Swimming up, swimming down a bit, but most of the time just hanging out. Very West Coast… and oh so salamander-ish. Until it comes to mating of course.. but then who wouldn’t’?

let’s face it, we are never going to see Rough Skinned Newts on Jeopardy, and even Wheel of Fortune is somewhat beyond their mental capabilities. Like all salamanders, or at least most of them, they seem to just.. be. Stumbling along, surviving and doing quite well generally but progressing one way or another? Developing? Nah… they have decided, and based on my observations so far probably rightly so, that they have reached their evolutionary end-point, so it is time to settle down and just be happy. Not deliriously happy; that requires too much activity and mental effort and might be mistaken for enthusiasm, God forbid.... Just content and bumbling along. As happy as a salamander.