CALIFORNIA NEWTS

(Updated 11 May 2008)


Most images have been reduced in size to speed downloading. To see an image in full size, CLICK on it. To return to the page, use the BACK button on your browser.


17 January 2008

The California Newt (also called the Orange-bellied Newt; Taricha torosa) lives most of the year in the woods among the dead leaves, eating slugs, bugs, and other things slow enough for a newt to approach, take into its mouth and swallow. Here's a young one in its usual habitat.

Newts look like lizards, which are reptiles and quick. Compare the newt with this lizard, photographed about 100 yards from the pond. Note the scales, long toes and claws.

Newts have no scales. They are actually amphibians -- members of the salamander family -- and they are slow. Adult California Newts are about six to eight inches long; the males are bigger than the females.

Around December and January they return to mate in the vernal pools or slow streams where they first emerged from eggs. There is a reedy pond about a mile up in the wooded hills south of Spring Lake Village in Santa Rosa, where I took pictures of a few of the many California Newts gathered there for the annual mating reunion.

The weather is cool and damp. There is no wind. The temperature is in the 40s, and the day is overcast, with the sun obscured or just visible as a bright place in the sky.

This is the winter home of these California Newts. Before the rainy season began, the reeds concealed whatever water the pond contained, but now it is full from the recent rains, rising well beyond the circle of reeds and out onto the grass meadow that surrounds it. The newts are on the bottom and the water is cloudy, but where it is shallow can you see them.

They spend a lot of time motionless or moving slowly, by either clasping the weeds or waving their tails like fish. During most of the year their tails are round like lizards’ tails, but for this aquatic interlude the males' tails have become flattened like fishes’ tails. There are hundreds of newts here, probably thousands, and many are quite visible as you walk along the water’s edge. Yet there are no herons, kingfishers or other birds or animals to feast on this abundance. In their world the newt is something that is left alone. Like the slow skunk, it would be easy prey, but it is seldom preyed upon. The newt’s skin contains a deadly poison called tetrodotoxin, like the poison of the puffer-fish the Japanese call fugu and that of certain deadly conchs. A newt would be the last meal of almost anything that might eat it, including humans.

At first I thought some of the newts had bright yellow eyes, but their eyes are really shiny black. If the eye looks yellow it is actually closed, covered by a bright yellow membrane. When newts are moving their eyes are open, but they are often covered with the yellow membrane when the newt is still. Are they sleeping?

A newt spends most of its time on the bottom, but every fifteen or twenty minutes it wriggles up to the surface, expels a bubble, takes a mouthful of fresh air and returns to the bottom. This one is about to wriggle back down after leaving his (her?) bubble, in which you can see the reflected silhouette of the photographer.

They're here, of course, to mate and reproduce. We can't see or understand the inter-newt communication that must be an important part of the process, but there's quite a bit of slow nuzzling and curling contact that’s going on, as well as the unmistakable act of mating. Here are three pairs, two of them getting acquainted and one pair in the characteristic mating posture. The male, an unusually large, pale newt with a mottled back, is on top of the smaller, more typically colored female, grasping her with both fore- and hind limbs.

The pair stayed this way for fifteen or twenty minutes, quite still or with only small, slow movements. Then, quite suddenly, the male wriggled away, rapidly for a newt, toward deeper water. He surfaced a minute later over by the reeds, left a bubble and quickly disappeared into the murk.

Here you can see lots of the gelatinous egg clusters in the grass. The clusters usually include from ten to twenty transparent eggs, each one with the nucleus clearly visible. As time goes by these nuclei will become recognizable embryos. The eggs stick to one another in the cluster, and also to the grass or weed that grows on the bottom. There are no egg masses where the bottom is bare mud, but where the bottom is green with grass and weed there are places where they carpet the bottom. Here the bottom slopes gently down from three to five inches deep.

Another visitor had left a single egg cluster on the grass beside the pond. It’s about an inch across.

I put it back in the water after photographing it. Who knows, if the eggs develop, maybe some of the young newts will be back here at the pond next winter.


12 February 2008

The newts I had been watching in January had no external sexual organs, and I assumed that the eggs were fertilized like those of fish: the male would release sperm into the water around the eggs after the female laid them while being embraced by the male (the process is called "amplexus", Latin for an embrace). I think I was wrong, but the mating process of the Rough-skinned Newt (Taricha granulosa), as described and illustrated on a website posted by Oregon State University, is so bizarre I hesitate to believe it.

To go to that website and make up your own mind, CLICK HERE.

A few days ago, on 9 February 2008, a bright, sunny Saturday, I went back to the pond. There were 30-40 people there, kids and adults, all interested in the newts. The water level was about the same as it was on my last visit. There was a lot of green algae in which small bubbles were trapped, but in many places the water was still fairly clear. I saw no newts, but the egg clusters had changed: each nucleus was now in the shape of a C, like a tiny cashew, less than 1/4 inch across.

In a few clusters, something else had happened too: in place of one or two "cashews" there was a larger white
structure, and the egg cluster had risen close to the surface. Why?


17 February 2008

Yesterday the air was still, the temperature was in the low 50s, and the pond was in cloud. In a few of the egg clusters the embryos were still curled like tiny cashews, but in most the embryos were a little larger and were no longer curled, but almost straight.


25 February 2008

A few wrigglers!

After some heavy rains the water was a couple of inches higher and somewhat more turbid, but many egg-clusters were still visible, and in most of them, like this one, I could see changes.

The embryos are bigger, and many of them are oriented more or less in the same direction. They are also a little reddish at one end. You may also be just able to see, on some embryos, tiny bumps that may be the beginnings of limbs. What you can't see, but what I happened to see because I spent several minutes watching each of several egg-clusters, was that in a few of them, one embryo would suddenly give a quick, vigorous wriggle, taking an S-shape momentarily before resuming its former only slightly curved form.

The picture above is of one such egg-cluster. Note that one of the embryos has been replaced by that cloudy bubble form. A scientifically inclined friend has suggested that it might be gas formed by digestion of an embryo attacked by a nematode. I thought perhaps the embryo that wriggled was reacting to the bite of some such invisible attacker, but I also saw wrigglers in two other clusters, neither of which had a cloud; could the wriggle be analogous to a human embryo's first kick?



17 March 2008

Gone!

I returned from a long trip three weeks later to find that the water level in the pond had fallen by about 8 inches, leaving some egg clusters in dry grass and many others in perhaps 1/4 inch of water among
swirls of wet grass.

In the image above, the cluster at lower left has embryos in it, but the vast majority of the clusters had none.

I saw quite a few clusters with round pits or craters on them:

Were these pits caused by bursting bubbles of gas, or did they reveal the exit paths of newt larvae? Does that sudden wriggle serve to liquefy the gel around them so they can emerge from that transparent mass of jelly?

I did see one cluster with embryos much more developed than those I had seen before, and two of them did that snap/wriggle while I was watching their cluster.

Note the large size of these embryos, and their longitudinal black line.

I suppose they'll be gone the next time I visit. I looked in vain for newt larvae in the water, but saw nothing like what I suppose they might look like. I'm sure they're there, perhaps hiding in the deeper water or just holding still among the weeds and algae.



11 May 2008

Sorry, no pictures this time.

We've been back to the pond a couple of times in the past weeks. It's loud with the calls of Red-winged Blackbirds, who also use the pond for their mating season. The water is murkier, with more algae, and the water level has fallen further. Looking intently into the water we saw nothing we could identify as a young newt (or tadpole -- the frogs breed here too). But when Dave Cox dipped his walking stick in the water and moved it slowly, we saw a few small, light-colored critters about an inch long dart a foot or so through the water. We couldn't see them at rest, and their appearance was so fleeting I couldn't hope to photograph them. We saw no adult newts either; I suppose they may have retired to the woods by now.

Tom Cooper, 11 May 2008