Full pantry

A couple of weeks ago, in a dark corner at the entrance to my carport, I noticed a tangly web, filling the whole corner. With a tiny spider near the centre. And an egg case she was guarding.

She's a common house spider, Parasteatoda tepidariorum, a good fly and moth catcher.

She catches more than flies, though. Last week, she had the leftovers from her latest meal hanging in the web.

Unidentified spider, probably Tegenaria domestica. Three times or more the size of his captor, not counting those long legs. Meals for a week!

How she does it: she stings the joints in his legs, where he has a flexible membrane rather than the hard exoskeleton, over and over, darting in and backing off before he can catch her. She knows her web; he doesn't, and gets stuck on the glue she avoids.

Spiders extend their legs using hydraulics, rather than muscles, as we do. To run, they increase the pressure in the cephalothorax (the head/upper body section), sending blood down the legs. Small muscles then return the liquid to the body, returning the legs to the relaxed position. So a shot of paralyzing poison to the legs soon invades the whole body. (From a previous post: see the entire story, "Unequal match: the sad story of Fang", here.)

When I found it, she had eaten her fill, and cleaned up most of the web she used to tie him up, leaving a bit holding that one leg. She eats the leftover web, too; spiders recycle.

The egg sac was empty yesterday, and no spiderlings were in sight. I swept up the corner and the messy web. I'm sure it will be back in a day or two.

Wise old eyes

Every week or so, I remove all my hermit crabs from the aquarium while it is being cleaned. And while they're milling about in the holding basin, I count them. I brought 19 with me from the mainland two years ago; there are 19 today. The smaller ones may or may not survive the first few months; it's a risky time, with all the molts and other growing pains. New babies arrive; some grow up. But the larger ones just keep trundling along, occasionally switching into larger shells.

Some species of hermit crabs can live up to 30 years. How old are my big grainyhand hermits? I don't know; they're not telling.

But they have wise eyes.

Ol' Fuzzy, at the front of the tank, checking me out. On red Turkish towel.

"Waves, Hi!"

These are smart beasties.*

The common intertidal hermit crab Pagurus granosimanus learns in one or two trials to reject an attractive, novel food (beef) when illness is induced ... Food aversion learning has never before been reported in a crustacean. (Wight, Keith, et al. “Food Aversion Learning by the Hermit Crab Pagurus Granosimanus.” Biological Bulletin, vol. 178, no. 3, 1990, pp. 205–209. JSTOR, JSTOR, www.jstor.org/stable/1541820.)

*Smarter than some humans I know.**
** At least, as far as food choices go.

Mini-micro havens

It snowed again yesterday afternoon. Then the snow turned to rain. Our streets were black, then white, then black again. But just a few miles away, on the mainland, the black is bad news; there, it's black ice. And the snow keeps falling.

Closer to home, if I drive over the hill that borders the shore, I find snow, six inches deep, undisturbed, and frozen hard enough to walk on without leaving a mark.

New forest coming, under snow.

Here on Vancouver Island, we live in a microclimate, its temperature and humidity determined by the encircling ocean currents, northbound from the warm North Pacific Current. Our summers are cool and wet, and our winters are usually mild (and wet; we don't tan, we rust.) Some years, there's no snow at all.

But microclimates have their own microclimates. Our shoreline strip is one. The backside of the hill is another. Forested areas have their own variants, depending on height of trees, direction of the slope, extent of logged areas, nearby rivers, roads and their traffic, and other circumstances.

And then there are the mini-microclimates. The warm zones around blades of grass, the wells at the base of stumps, hollow logs, even the ruts in old car tracks. Each imperfection in the surface shapes the wind currents, captures or blocks the sunshine, funnels off the rainwater. And in these mini-climates, plants and animals wait out the cold weather.

Baby Douglas fir and shrubs, each in its own warm well.

Each living plant affects its climate in various ways. It absorbs sunlight, which otherwise bounces off the surface of the snow. It deflects drying winds. And its own living processes produce a minimal amount of heat. Enough to melt the snow up against the branches, and provide cover for other small plants.

An old stump in its own mini-climate, harbouring evergreen salal.

Two more stumps. With lichen, salal, and bare twigs of deciduous shrubs. These will have an early start to their spring growth.

A few small trees and shrubs share a warm spot.

Even a rock can build a mini-climate. It absorbs more warmth from the sun than the surrounding earth, which is cooled by air pockets and seeping ice melt. The rock radiates this extra heat into the snow around it.

Snow on the side of the road, tossed up by a snowplow. Even this can create a disturbance in air flow and sunlight. The lump itself, exposed to the wind, is frozen hard, but the sunny surface is slowly melting, making that icicle.

A side road, unmarked on the map, with ruts and tracks of a dog or coyote, made before the snow froze hard. The forested and ferny areas are just warm enough to melt off the snow before it freezes.

And there's another mini- or really, not so mini - microclimate, usually unseen. Underneath that frozen snow cover, the ground is protected from freezing winds, and stays just above freezing. And there, the little creatures wait out the winter, sleeping or burrowing deep into the warmish earth.

Back at home, a few of my spring crocuses are pushing through the wet soil, hidden in a mini-climate of their own between a wall and a staircase.