I discover a hoax. And some eggs.

It's been a busy weekend, what with company and making the list of Rock Flippers, (What fun I've been having! And I've met so many new - to me - great bloggers!) but I'm finally getting around to posting my own IRFD report, in two parts.

I stayed close to home all weekend, dashing out every time I took a break to see if I could find a good rock. My first forays were a bust; interesting wildlife, lousy photos. Saturday afternoon, though, I noticed a rock beside our street, a big rock I had passed hundreds of times without ever looking at it. It was far too big to even consider tipping over, but I was getting desperate.

Big, chunky, fake rock.

Then I noticed that white edge. It looked like a coating of barnacles, but here? I went closer and touched the rock. It was just painted styrofoam. How had I missed that before?

A nudge with a couple of fingers, and over it went. And look what I found!


They must be eggs, but what laid them, I don't know. I can see something inside, looking mostly like a bubble of air.

This blurry photo gives an idea of the size; that's a fat earthworm. The whitish thing on the right is a dead woodbug. I'm wondering whether it is warmer under the fake rock than it would be under a real one; I'll have to monitor it over the winter.

A few hours later, I was out again. I crossed the street to our productive vacant lot.

Big slabs of debris from building sites, now almost hidden by the weeds. Too big for me.

Smaller chunks. I could handle these.

Here, I found the ever-present woodbugs, slugs, and earthworms. And the spiders that feast on the woodbugs.

Dead weed stalks make great camouflage for a leggy spider.

Funnel-web spider with packed lunch; a beetle wrap.

And I began and ended with the next generation. These were cocoons containing ant larvae. The adults were frantically collecting them and hauling them down cracks.

All in all, a good haul. And Sunday's flipping yet to come; that will be next post.

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Upside-down maternity wards

When the tide goes out and the sun shines, the beach residents go into hiding. Some burrow into the sand, others hide in the crevices between rocks, and many move to the underside of rocks and other shells. Flip a rock, and crabs scuttle out of sight to the new underside. Snails, barnacles and limpets are not so agile, but they close themselves down tightly against the heat and light.

I was flipping rocks on Crescent Beach, always remembering to put them back where I found them before the animals there got sunburned. (Crabs that had moved to the new bottom, now had to reverse direction.) On the underside of many rocks, this last week, I found masses of a yellowish, flecked jelly:

Flipped rock, with limpets and jelly.


Closer view of the jelly, with snails. (Sitka periwinkle, Littorina sitkana.) It reminds me of tapioca pudding.

They looked like egg masses to me. But whose eggs?

I had to search long before I found them. Each type of mollusk lays their eggs in a particular formation; the individual stalked "sea grapes" of the whelks, tiny "donuts" of the chink snails, strips, spirals (sea slugs), the eel-grass coating I found on this beach last year (still unidentified), and these blobs. Unfortunately, few books and websites mention these eggs; even fewer show recognizable photos, and fewer still link the photos to the specific creature that lays them. Most of the egg masses that I found had snails on or around them, but they were a mix; mud snails, periwinkles, whelks and black turbans.

I read up on all the snails, and finally found a PDF from the Alaska Natural Heritage Program, on the Sitka periwinkle. Not only does it describe the snails, but it includes a paragraph on reproduction with a description of the eggs. (No photograph, though.) And the descriptions match!

Sitka periwinkle with egg mass.

"After copulation females lay 50-400 fertilized eggs which are enclosed in a thick, transparent, gelatinous material; individual egg masses measure 5-15 mm but communal laying by several females often results in large egg masses measuring up to 10 cm, containing 2,000 or more eggs. ... Egg masses usually attached to and under rocks and seaweed in the upper intertidal zone."

Most of the egg masses I found were these communal sites.

That's a lot of eggs! I did a bit of calculating; at a minimum of 50 eggs per female, a success rate of only 4% will maintain the population. (They need 2 successes per male/female pair.) With 400 eggs, half a percentage point will do. In other words, most of these eggs won't make it.

From the PDF, again:

"Veliger (snail larva) develops shell within a week inside egg case, then hatches in around 30 days and begins to consume jelly of egg mass and diatoms which may have colonized the jelly surface."

Survival of the quickest, I think you could call that.

The individual eggs in the jelly catch the light. They vary, in different masses, from pale yellow to a burnt orange.

Someone had been flipping rocks on the beach before I got there. Where they had exposed egg masses and left them face up, the jelly was dry, and looked cracked and lifeless. It was a good reminder of the importance of leaving things as I found them.

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Looking at an egg again

Last Monday, I posted a photographic challenge, borrowed from an article in WaveLength Magazine; take 36 Photos of an egg.

A few of my readers indicated that they planned to try. So far, one, at Cicero Sings, has posted her photos in the Flickr group I set up for the purpose. (I hope that there will be more, later.)

Robin's egg, collected after the chick had flown.

Well, I took my 36 photos, and more, and learned something in the process, enough, maybe for several blog posts.

First, though, Cicero's eggs:

We each looked at the assignment from our own perspective; however, a couple of shots are remarkably similar; both Cis* and I photographed the freckles of the egg shell with light behind it, both of us showed the eggs in the carton, both broke and cooked the eggs. There the similarities end.

Cis saw the eggs from a warm domestic perspective, cooking, garnishing and serving them. Her photo of a breakfast laid out on the placemat, eggs with a cinnamon roll, water in a glass, coffee, brought back happy memories of Cariboo kitchens, with the coffee fragrant and the conversation relaxed; thanks, Cis!

I am weird, though. And not domestic, at all. Frying an egg was the limit. (And besides, I got hot oil on my lens and had to clean it. Not good.)

I spent some time just looking at the egg. Paying attention. Asking myself questions. And then almost randomly, wandering around to see what seemed to have some association in my mind to the "eggness" of the egg.

One of those associated objects was a bowl of rocks.


An egg is fragile. One crack on the side of the frying pan, and it breaks wide open. A few pecks from the baby -- how tiny and weak he is! -- from inside, and the shell gives way. We crumble the shell in our hands to spread on the garden to discourage slugs, smush a half-dozen into a handful to throw in the trash.

But an egg is incredibly strong. Grab one just right, and you can squeeze with all your strength without breaking it. Cut two egg shells in half, and you can stack books on them, even sometimes stand on them without crumbling them. (Internet Encyclopedia of Science, para.4)

Therefore, rocks.

What makes an egg so sturdy without sacrificing its open-sesame policy for the chicks? The shape. The round sides transmit stress evenly along the walls; it is only when the egg is impacted from a cross-wise direction that it breaks easily. Therefore, we crack the egg against a bowl or the frying pan; the chick pecks at one spot, against the inward curve.

Googling for formulas (how strong is eggshell strong?), I found other fascinating facts:

Did you know (I didn't) that the reason sea-going birds can lay their eggs on narrow rock ledges, without a nice deep nest, is that their eggs have pointy ends?

Murres lay one egg on a bare nesting ledge. Their egg is very pointed. If bumped, the egg is more likely to roll in a tight arc than to roll off the cliff. (Royal Alberta Museum)

I wonder if that applies also to pigeons that lay eggs on building ledges, held in place with only a loose stick or two? Seagulls, cormorants, etc.?

RAM goes on to explain the eggs of those marsh birds with the nests right down on the wet ground:

Shorebirds normally lay four pointed eggs. In the nest, the eggs are oriented with their pointed ends towards the centre. This minimizes the amount of space needed to form the nest and increases the efficiency of the heat transfer from parent to egg during incubation.

Of course, a spherical egg is more economical, conserves heat better, is stronger. But they do roll. Great Horned Owls lay spherical eggs; I think I can assume from this that their nest is deep enough to prevent loss.

So much to learn! What fun!

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*Cis: not her name, but derived from the blog name.