Shallow Thoughts : : nature

Hollow oranges

Hollow oranges keep turning up on our lawn under the orange tree. Sometime we even find them still attached to the tree.

We're not sure what's eating them, but I have a theory.

A few weeks ago, I kept finding that as I walked across the backyard, something would fall out of one of the trees, either the orange tree or one of the guava trees. It was always barely viewed out of the corner of my eyes, but seemed about the size of a guava and fell and landed with about the same sound falling guavas make.

Only problem was: guava season is still three months away, and they haven't even started to grow on the tree yet.

I had speculations about what was going on, but I wasn't sure. Finally, a few days ago, I came out the office door and something fell out of the guava tree right in front of me.

It was guava sized, grey -- and furry, with a long naked tail. I got a good look at the mouse as it scooted across the grass to hide under the deck.

They're welcome to an orange now and then. We have lots of oranges. And they're polite about it -- they clean out one orange at a time rather than spoiling lots of them with small nibbles.

Tags: nature, urban wildlife
[ 09:06 Jul 14, 2010    More nature | permalink to this entry ]

Huge brood of wild turkeys at Rancho San Antonio

Late last week in the field next to the parking lots at Rancho San Antonio we had a chance to watch a wild turkey family foraging in the dry grass. Two adults and twenty chicks -- that's quite a brood!

Two of the chicks got into a scuffle and kept it up the whole time we watched them. The adults didn't seem interested, but some of the other chicks gathered round to see what was going on.

Photos: Wild turkeys.

Meanwhile, in other nature news, the hot weather has brought the odd unidentified chlorine smell back to the redwood forests. On the weekend, when we were having 90-degree days, the smell was very noticable around Purisima and El Corte de Madera, and on a few parts of Highway 9. Today, though the weather is cooler, the smell was everywhere on the Skyline trail at the top of Sanborn. Still no idea what's producing it.

Tags: nature, birds, chlorine
[ 19:23 Jul 07, 2010    More nature/birds | permalink to this entry ]

Tiny froglets at Picchetti Ranch

You read so much about the dire state of amphibians in today's world. They're delicate -- they can absorb toxins through their porous skins, making them prey to all the pollution the human world dumps at their doorstep, as well as being prey for a wide assortment of larger animals and prone to infection by parasites. I remember seeing lots of frogs around ponds in the woods when I was growing up, and these days it's rare to see a frog in the wild at all.

But sometimes you get lucky and get an indication that maybe the state of amphibians isn't as dire as all that. Mark Wagner gave me a tip (thanks, Mark!) that the pond at Picchetti Ranch was literally hopping with frogs. I thought he must be exaggerating -- but he wasn't.

They're tiny, thumbtip-sized creatures and they're everywhere around the margin of the lake, hopping away as you approach. It's tough to get photos because they move so fast and like to hide under grass stems, but like anything else, take a lot of pictures and you'll get lucky on a few.

The scene is absolutely amazing. If you're at all a frog fan in the south bay area, get yourself to Picchetti and take a look -- but be very, very careful where you step, because they're everywhere and they're hard to spot between jumps.

I unfortunately lack a good amphibian field guide, and couldn't find much on the web either, but some people seem to think these Picchetti frogs are Sierran tree frogs -- which apparently are sometimes are green, sometimes brown and have a wide range of markings, so identifying them isn't straightforward.

Photos: Tiny frogs at Piccheti Ranch.

Tags: nature, amphibian, frog, photo
[ 18:14 Jun 30, 2010    More nature | permalink to this entry ]

Newt nookie!

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.

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.

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

Butterfly romance!

I was in the back yard pruning the star jasmine when something came buzzing through the air and smacked into my shoulder.

It turned out to be two skipper butterflies, locked in what I can only presume was an amorous embrace.

Dave got his camera and documented the scene: butterfly romance photos.

They stayed on my shoulder for another 20 minutes, imperturbable, while I continued with yard work.

Tags: nature, butterfly
[ 15:20 Sep 27, 2009    More nature | permalink to this entry ]

Bullfrogs in stereo

The Walden West pond is hopping -- literally! This afternoon around 3pm the pond's resident bullfrogs, who normally just float quietly in the scum on the surface, would suddenly hop out of the water for no obvious reason, then settle back down a few feet away. One pair was apparently mating like that, the larger frog hopping onto the back of the smaller frog, then immediately off again. And the pond was full of sound, sometimes with two or more frogs booming at once. Bullfrogs in stereo!

I didn't have the SLR along, but some of the frogs were close enough (and calm enough not to submerge when we got near them) that I was able to get a few decent shots.

But I really wanted to capture that sound. So I put the camera in video mode and shot a series of videos hoping to catch some of the music ... and did. They sound like this: bullfrog (mp3, 24kb).

Despite the title of this entry, the recording doesn't have any interesting stereo effects; the only microphone was the one built in to my Canon A540. It did okay, though! You'll just have to use your imagination to place two frogs as you listen, one 20 feet to the left and the other 15 feet to the right.

How to extract the audio from a camera video

(Non open source people can quit reading here.)

Extracting the audio was a little tricky. I found lots of pages ostensibly telling me how to do it with mencoder, but none of them seemed to work. This did:

mplayer -vc null -af volume=15 -vo null -ao pcm -benchmark mvi_8992.avi

I added that -af volume=15 argument to make the sound louder, since it was a bit quiet as it came from the camera.

That produced a file named audiodump.wav, which I turned into an mp3 like this:

lame audiodump.wav bullfrogs.mp3

Tags: nature, bullfrog, linux, audio
[ 20:42 Jun 03, 2009    More nature | permalink to this entry ]

Bay Area Wildflowers

Spring is in full swing, and all around the bay area the parks are ablaze with the colors of wildflowers -- blues and lavenders at Alum Rock, blues and yellows at Rancho San Antonio and oranges at Arastradero.

I've been shooting photos of wildflowers for years, always intending to collect them into a web page -- for my own reference (I always forget which wildflowers are which) as much as anyone else's.

At the same time, I've been gradually working on finding better ways of displaying photos on gallery pages. Most of my old pages use tables, which work fine in all browsers but don't scale very well with page size -- 4 images across may look fine in an 800 pixel wide window but look pretty silly at 1600 pixels. After playing with various CSS-based ideas for showing images and captions, I finally found the answer ("display: inline-block" is the key) on this brunildo.org CSS gallery demo. I adapted it for my site and wrote some PHP glue to generate the pages, and here's the result: Bay Area Wildflowers.

Update: Isn't it always the case? Just when you think you're done with something, you find out there's more to do. I wrote the preceding a week ago and then didn't manage to post it before leaving for a desert trip. And the desert was blooming! So here I am, ba-wildflowers site barely made public, newly back from the Mojave with a disk full of desert wildflower photos that aren't from the bay area. Looks like the "Bay Area Wildflowers" site needs to expand to a wider area ...

Tags: nature, wildflowers
[ 21:13 May 01, 2009    More nature | permalink to this entry ]

Akk and the Night Visitor

Last night we spotted a masked bandit at the office door.

The raccoon was in a nutty mood -- or at least in a mood to eat a lot of hazelnuts and cashews.

Happily, I had the DSLR on my desk and was able to sneak some shots. Last time we were visited by raccoons I established that unlike most wildlife, raccoons definitely do notice a camera's flash, and don't like it a bit. (Most birds, reptiles, amphibians and even rodents are remarkably un-bothered by flash and don't seem to notice it at all.) So the Rebel's ISO1600 and ability to focus in dim light came in very handy. (Have I mentioned how much fun it is having an SLR again?)

The 'coon licked the nut shelf clean, then headed north to the neighbor's house. This bandit worked alone -- no partner this time.

A few more raccoon photos here.

Tags: nature, raccoons, urban wildlife
[ 22:44 Sep 24, 2008    More nature | permalink to this entry ]