Sunday, January 17, 2010

256 Newts

How many newts?

Last night, a night misting in anticipation of a storm, we undertook the first-of-the-year frog surveys. We visited all four Dipper Ranch ponds from 8 pm to midnight walking about 1.5 miles downhill and then the same route back again. The fog kept all surfaces wet without totally blocking the moonless night sky and the temperatures were in the low 40's. Good conditions for amphibians.

As we walked out of the house, we could hear a treefrog chorus in the distance. I had heard occasional treefrog calls for the last month, but this was the first night of the rainy season that we could hear multiple frogs sing together. When we passed through the gate around the farmyard, we heard several treefrogs echoing off the metal sides of the cattle trough in the nearby corral.

Sneaking out of the pond on a Saturday night.

The Woods Pond had shallow water, a small amount of water draining through the outfall, and we did not see or hear any treefrogs or see any newts. That changed once we climbed the berm around the nearby Newt Pond. The Newt Pond was a few inches deep and no water was inflowing through the rusty pipe from the uphill spring. We saw 12 coast range newts wandering around the grass at the edge of the pond. Many of them were swollen with slick skin and razor edges to their tails indicating they had already spent time in the water. One of the land-based newts was eating an earthworm, while 6 newts were swimming about the cloudy pond. One treefrog was sitting quietly on the grass about 15 feet from the edge of the pond.

After they have been in the water, the skin on the back of male coast range newts changes from a bumpy, dark surface to a smooth bright orange.

As we climbed the slope above the Newt Pond, passed its feeder spring and walked out into the upper meadow, we saw 27 newts rambling about. We started to get excited. The newts were wandering in many different directions, sometimes alone and sometimes following another's tail.

Newts can travel long distances to breeding ponds and streams, often tumbling down steep slopes and creeping under and crawling over barriers like this pipe.

Between the gate separating Pasture 3 from Pasture 1 and Mustangs Rock, there were 65 newts on and alongside the road. They didn't seem to mind our close inspection via headlamps and usually continued about their business. Still 1/2 mile from the nearest pond and perhaps a quarter mile from ephemeral drainages, we continued to see the earth crawl with 54 more newts as we ventured downhill to the Monotti Pond (formerly called the Plum Pond).

We were not the only creatures wandering in the misty night, as nearly 100 yellow dots shined back at our headlamps. Although I claimed they were aliens, my ranch-raised companion was not fooled. The cattle were curious to see humans walking about at night and did not clear the ranch road until we were within a dozen feet of them. Then they followed us at a distance down to the Monotti Pond as we passed 13 newts and the treefrog chorus swelled.

How the male Sierran treefrog makes such a loud sound to call in the female frogs.

The Monotti Pond had no outflow, but treefrogs were loudly calling from the cattail stand. The treefrog chorus would stop temporarily whenever we talked or we or the cattle moved, but soon one frog would call and then, not to be left behind in courting the females, others would join in, and the din would start all over again. Within a few minutes, the frogs became accustomed to our presence so that I could walk around the pond without stilling their bellows and I counted 4 newts on land near the pond and 20 newts swimming about the shallow water. We decided not to count the frogs as they were harder to see than to hear.

We usually see newts in ponds where we witness their aquatic breeding. On rainy nights, their amphibian nature allows them to leave the pond and hunt for terrestrial invertebrates.

With our ears ringing, we headed towards the Mallard Pond. Of the 47 newts we passed on the way, many were eating earthworms and one swallowed a pill bug before our very eyes. The Mallard Pond was eerily silent with 5 newts on the land and 3 in the water. The Mallard Pond is surrounded by forest, so perhaps it takes longer for the amphibians to seek it out than the Monotti Pond which is completely surround by grassy slopes.

With feet braced, this newt tugs a resistant earthworm out of its hole.

On the return trip, we saw plenty of newts but did not count them. We realized that the newts which were still with their heads tilted or pointed, were probably hunting since many of them were peering under leaves or down holes. Once a newt got one end of the worm between its jaws, it would intermittently lunge forward and gulp down another section of the struggling worm. Newts have small teeth, thus they were not severing the earthworms, just slowly swallowing them whole. This explains why some newts were dragging big bellies as they slipped back into the pond.

Midnight greeting party - the California toad

When we finally reached the farmyard, a large California toad greeted us in front of the barn. We did not see or hear any red-legged frogs all night. We will keep surveying the ponds and hope to catch the earliest arrival of these big frogs, and record the earliest dates of frog and newt mating and egg laying. 256 newts in a night (64 newts an hour) has altered my perception of the night life around here.

As the night falls, poisonous orange predators emerge from ponds or their dens
and hunt down the slimy & wicked.


See also:
Coast range newt, Taricha torosa torosa
Sierran treefrog, Pseudacris sierra (formerly called Pacific treefrog, Pacific chorus frog, Hyla regilla or Pseudacris regilla)
California toad, Bufo boreas halophilus

3 comments:

  1. your mind never ceases to amaze me.

    ReplyDelete
  2. Sooo awesome! Please let me know if you ever need help with this kind of thing. As I am both unemployed and a natural night-owl, I would love to come along! (I can help with things in the daytime, too.) :)

    ReplyDelete
  3. Oh my goodness! It's like watching the nature channel.

    My rugrats would love it!

    ReplyDelete

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