Newt nookie! (Shallow Thoughts)

Akkana's Musings on Open Source, Science, and Nature.

Wed, 20 Jan 2010

Newt nookie!

[Newt nookie at Lake Ranch] Last weekend, on a tip posted on a local birding list, we hiked up to the little pond at Lake Ranch, above Sanborn county park, where a major California newt orgy is in progress.

There were thousands of newts throughout the lake, but especially by the dam, where they were mating and laying eggs.

I had never realized how much the male newts' appearance differs from the females -- or possibly, it doesn't except at this time of year. Most of the year, when we see newts they look like these females, with orange-red skin and lizard-like feet. But here the males look very different: larger, darker, often patterned with stripes or spots, with huge flipper-like feet and greatly flattened tails.

Most of the females were gravid with eggs already. The males seem to be able to tell when a female has already been fertilized, but only from up close: they'll pursue a female to a few inches away, then turn back if she's recently mated.

We saw some multi-newt orgies, with two or three males nosing each other to get access to a female; but mostly we saw pairs clasped in long-lasting embraces. We watched a few pairs for five or ten minutes.
[California newt laying her egg sac]

Some of the females laid their grape-sized egg sacs near where they mated, by the dam; but upstream, closer to the Black Rd end of the pond, we found a nursery where the pond floor was just covered with egg sacs. Is it safer for the eggs here, away from the newt festivities? Or is the temperature or oxygen content different?

Photos are a bit challenging. There's a lot of reflection off the surface of the water. The raw photos are just a sea of murky green, but a little contrast boosting in GIMP, and sometimes a bit of layer mode/layer mask work, brings out a lot more detail than I expected.

There were a few frogs singing, too. We couldn't see the frogs, but we did see a few schools of what might have been tadpoles (or else tiny fish). We also saw one huge tadpole, with a head like a squashed ping-pong ball. I hope the bullfrogs from Walden West pond haven't migrated up to Lake Ranch. It's fun to watch them at Walden West, but bullfrogs could wreak havoc on the pond's other wildlife. (Can bullfrogs eat newts? Most animals can't -- newts have poisonous skins. But we've never seen any newts at Walden West.)

If you go to see the newts, watch your step on the trails. After egg-laying, the females apparently leave the pond and go wandering cross-country. (Where do the males go?) We saw at least three females heading down the steep trail toward Sanborn, and a couple more on the flat trail above the lake that heads toward Black Rd. They move slowly and purposefully, and can't scurry out of your way to keep from getting stepped on. So be careful, and enjoy the show!

Newt nookie photos here.

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[ 11:06 Jan 20, 2010    More nature | permalink to this entry ]