Ill wind with no athletic aptitude.

The wind blew hard overnight and early this morning. Clang clang clang went the baffle in the duct from the dryer.

Cones were driven from the trees,

from spruce and Douglas fir,

and from western hemlock, whose strategy is numbers, not size.

But no matter how much it huffed and puffed, how angrily it shook the branches,

the wind couldn't blow down the soccer ball from the paper birch at the park.

More than bluster required.

Tiny, tidy.

I stood for an hour, listening to the CBC on my little radio, which was hanging by a strap from one of the knobs of the tripod. The CBC will sustain you, if you let it. I was waiting for the Black-capped Chickadees to come to their nest hole-in-progress, which they seem to do every morning at about 11 AM.

How can they make such a perfectly circular hole?

Chickadees often act as primary cavity nesters (i.e., create their own nest holes). But since they lack the size and excavating equipment of, say, a flicker, they require a tree with relatively soft wood. A paper birch snag in an advanced state of decay is suitable, provided it’s not on the verge of collapsing. This hole is about twenty feet up, three feet below the broken top of the snag.

Chickadee entering hole.

Finally, at 10:58 (Chickadees are not only dapper, they’re punctual), a pair appeared and landed in a neighbouring tree. One darted into the hole, and disappeared for a few seconds. Out it popped, with a scrap of pulpy wood in its bill.

Click to see wood chip in bill.

It flew away, carrying the wood. Immediately the second bird flew into the hole, and it too darted out quickly, carrying a scrap of wood in its bill.

There was a lag, as they went somewhere. Chickadees are so tidy, they probably took the wood chips to a recycling depot.

This happened again and again. They arrived together, entered the hole to remove more wood in quick sequence, and then disappeared for a few minutes. Perhaps, in arriving and leaving as a twosome, instead of as two individuals with evenly spaced intervals between, they are keeping a lower profile, acting almost as a single bird, which would draw less attention to their nest. They would also be affording each other the protection of a pair of eyes on the outside--they got each other’s back. I can understand these things.

What I don’t understand is how they can make such a perfectly circular hole.

Green eggs and jelly.

I have been reading about salamanders lately. I came across a paper I had not seen before. It addressed a question that hadn’t occurred to me, but should have, I think.

You see, salamanders of the genus Ambystoma, which should be breeding in a pond near you, soon if not already—if you live in temperate North America—lay eggs in the water in masses of jelly attached to something, often a submerged stick. The jelly masses absorb water, becoming quite large in some species such as A. gracile, the Northwestern Salamander, which is one of two species found in southwestern BC. Well, here’s the question: How do eggs in the middle of a large mass of jelly undergo the gas exchange necessary for development? Where do they get the O2? Diffusion of dissolved oxygen through centimetres of glorp must take an awfully long time.

Northwestern Salamander eggs, recently deposited. Cypress Mtn, BC.

Well, a clue, perhaps. As early as the late 1880s it had been noted that the originally clear, gelatinous eggs of these salamanders would turn green to the point of obscuring the developing embryos. The culprit was a single-celled green alga that lived within the egg envelope. The alga was named Oophila amblystomatis (egg loving, of Ambystoma; note: there was at some point a typographical error, confusing Ambystoma and Amblystoma). The presence of the alga did not harm the eggs. Could the alga be providing O2 to the embryos, and accepting CO2 and nitrogenous waste?

A short answer from Wikipedia:

"Oophila amblystomatis, commonly known as chlamydomonad algae or salamander algae, is a species of single-celled alga. The Latin specific name means "loves salamander eggs". It does not occur anywhere in nature other than in the eggs of a few amphibians, such as those of the spotted salamander, Ambystoma maculatum. The alga can invade and grow within an egg's jelly. Once inside, it metabolizes the carbon dioxide produced by the embryo and provides it with oxygen as a result of photosynthesis. "

Older eggs, greening up. Rice Lake, North Vancouver.

A longer answer is that this seems to be true, but it turns out to be somewhat complicated, especially for the eggs farthest from the edges of the jelly blob. These are exposed to adequate or excess levels of oxygen during daylight, while the alga is photosynthesizing, but experience hypoxia (low O2) at night when the algae are using O2.

Here is the paper that applies. A more recent paper giving additional detail and cited by the brief Wikipedia account is here. (Or see Ref list below.)

A lot goes on in a jelly blob. If you’re a developing embryo near the edge, your gas exchange situation may be better, but your chances of being eaten by a Rough-skinned Newt are increased. In the middle, you may not be eaten, but you are subject to wild swings in oxygen levels, which may compromise your development. Hedge your bets, sit in the blue seats. *

*In the hockey shrine of Maple Leaf Gardens, after about 1970, there were five colours of seats, arranged in concentric rings. Starting closest to the ice, the colours went gold, red, blue, green, grey.

Addition: For an eye-popping look at the inside of a salamander egg mass, see this astounding image by David Blevins. Your local pond is a sci-fi universe, with larval aliens in suspended animation.


Refs:

Pinder A.W. and S. C. Friet. 1994. Oxygen transport in egg masses of the amphibians Rana sylvatica and Ambystoma maculatum: convection, diffusion and oxygen production by algae. The Journal of Experimental Biology 197, 17–30.

Valls, J. H. and N. E. Mills. 2007. Intermittent hypoxia in eggs of Ambystoma maculatum: embryonic developmentand egg capsule conductance. The Journal of Experimental Biology 210, 2430-2435.

Some salamander. Some tail.

Ensatina eschscholtzii oregonenesis.

Ensatina is a rare case of a herp being commonly known by its generic name. What does Ensatina mean? I looked, but couldn't find the answer. The salamander in this picture, about three inches long including the tail, was found during the Quest for the Giant Salamander.

This small, lungless species (E. eschscholtzii), in its seven subspecies, ranges from southeastern Vancouver Island and the Lower Mainland of BC to northern Baja California. It occurs in most of the western half of California, minus the Central Valley. The subspecies found in BC is E. e. oregonensis.

What catch my eye as I look at the picture are the constrictions on the tail. The first constriction is supposed to be there, the second, I’m not so sure. It might be a point of fracture from which the tail tip regrew. Ensatinas autotomize their tails as a defensive tactic, usually at the basal constriction, hoping to baffle a predator with a twitching distraction as the rest of the salamander gets away.

But there’s more to their tails than this. According to Amphibiaweb,

“The dorsal surface of ensatina tails contains large, densely packed poison glands, and a sticky, milky secretion is exuded when the animal is threatened (Hubbard, 1903). Ensatinas can autotomize their tails at the constricted base, and autotomized tails bend wildly for several minutes (Stebbins, 1954b; Wake and Dresner, 1967). Beneski (1989) found that ensatina tails stick to the mouths of garter snakes, inhibiting further consumption. “

Aha. The peanut butter strategy.

And more,

“It takes about 2 yr to regenerate an autotomized tail (Stebbins, 1954b; Staub et al., 1985), and tails are rarely dropped unless conditions are life threatening (Beneski, 1989).”

But tail autotomy, if it comes to that, doesn't always work out. According to a page from Santa Rosa Junior College,

“Among the predators of Ensatina are the raccoons. Adult raccoons will eat Ensatina beginning with the head down to where the tail begins, and the tail is then discarded.”

There is something very unfair about that.

there was a snail here!

House of Roots. Sculpture in Paulik Park, Richmond.

The view inside, and on a cross-piece...

Immortalized.

Suburban spring.

The moss in the recently-limed lawn is growing thicker and greener and angrier,

Pigeons at the mall are arranging nests beneath the unblinking stare of a plastic owl,

And the shopping carts have returned to their spawning ditch.

Sea of green.

Imagine looking out the window—every window—at a rolling sea of trees.

What fun.

House on a hill, Belcarra, BC.

Which begs the question: Why are all the blinds closed?

Festival of the Trees Number 33 is now up at local ecologist. Drop by and see the trees.