Five minute expedition

We've had a busy day, driving back and forth, hauling stuff around, unpacking, shopping ... barely time for a quick walk to the corner and back. But even in that nibble, Strathcona doesn't disappoint.

The colours are vivid:

Purple clematis and a greenish-white hydrangea.

Shining white miniatures along the sidewalk.

Cherries, not quite ripe.

Unidentified flower head, with ant.

And the decor surprising:

Front porch pets.

The people front door is just to the left. Wasps enter on the right. Good neighbours.

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A walk in the garden

Blue jeans, Crescent Beach.

And with that, we're off to Strathcona, where sights like this are commonplace, for our annual week of house-sitting. Let's hope the sun shines!

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Brownie cooks Christmas dinner

Brownie is a Steatoda bipunctata, a two-spotted cobweb spider. I've been housing her since last November in a big glass jar. (Previous posts: Mistaken identity, twice over, and To spin or not to spin, spider #4.)

Small sowbugs make up the bulk of her diet; fortunately, they're plentiful in this wet climate. But I try to introduce a bit of variety sometimes. I read somewhere that lab Steatodas raised on boring diets don't do too well.

Brownie and patterned sowbug.

Every so often, I empty Brownie's jar to get rid of the layer of dead carcasses at the bottom, then supply her with a few fresh sticks to tie the new web to. She doesn't appreciate this. She usually spends the next few days sulking in a corner, not moving, not eating.

So yesterday was cleaning day. This time, because she somehow manages to pull down the sticks and tie them together at the bottom, limiting her mobility, I gave her a framework of leftover pipe cleaners. I hope they will be more resilient. (That's to explain the "Christmas decorations" in the next photos.)

In the evening, I found a winged ant in the garden, and brought it in to Brownie as a peace offering. It was a big one, half Brownie's length again: interesting! She forgot her snit, and stalked the ant from a distance for a full day. Tonight she caught it. And it put up a fight.

The battle.

I saw them at it, the two of them hanging in the web, vibrating. The ant kept snapping at the air, trying to turn its head to get at the spider. But Brownie had sunk her fangs into the edge of the thorax, and hung on like a bulldog. Nothing would shake her off, and the ant couldn't twist far enough to reach her.

(Usually, she bites her prey, then backs off and starts to tie it up. Looks like she's smart enough to modify her procedure when the occasion calls for it.)

She held on, never leaving that position, for over 15 minutes, until the ant was just barely kicking. Then she wrapped it and hauled it up to her new dining room.

She's been busy eating ever since. And I think she's forgiven the impertinence of her housekeeping staff.

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As blue as the sky

Skies and flowers at Crescent Beach:

Teasels

Lobelia with fuschia

Delphinium

Love in a mist

A Skywatch post

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Of feathers and milk

A year ago last February, we happened to walk under this pier and look up. The pigeons were nesting already. I was wondering, last week, how many there would be now, as summer approaches.

Crescent Beach pier

The underside of the pier, with nests.

Just as before, each crossbeam held at least one nest, or at least a few pieces of weed and straw to simulate a nest. Do chicks never fall out of bed?

Two chicks, two adults.

This June, they're probably well into their second brood of the year, and the squabs (pigeon chicks) are quite large already, but still only partially feathered. (Most of these are probably about three weeks old; compare with the set of photographs at the bottom of the Wikipedia page.) I love the yellow "Mohawks" they are wearing.

Feeding baby.

I watched the parent feeding her chick for some time. (S)he doesn't come and go, each time with fresh food, as some other birds do (chickadees, for example). She sat there the whole time. Every minute or so, she would close her eyes and open her mouth, and the chick would reach in for a fresh mouthful of milk and mush. She must have been regurgitating a cropful, bit by bit.

Crop milk bears little resemblance to mammalian milk, being a semi-solid substance somewhat like pale yellow cottage cheese. It is extremely high in protein and fat and contains more of it than cow or human milk. Both male and female adult birds produce crop milk and share in the feeding and care of the young. ...

Pigeon's milk begins to be produced a couple of days before the eggs are due to hatch. The parents may cease to eat at this point in order to be able to provide the squabs (baby pigeons and doves) with milk uncontaminated by seeds, which the very young squabs would be unable to digest. The baby squabs are fed on pure crop milk for the first week or so of life. After this the parents begin to introduce a proportion of adult food, softened by spending time in the moist conditions of the adult crop, into the mix fed to the squabs, until by the end of the second week they are being fed entirely on softened adult food. (Wikipedia)

Almost grown up.

Curly yellow feathers.

This pair, one brown and one white, were smaller and fluffier than the adults, but seem to be completely feathered already.

Feral (city) pigeons breed several times a year, at any season, although they prefer the warmer months. They incubate a clutch of two eggs from 15 to 19 days, on a swing shift:

Parents continuously incubate eggs for about 18 days, females from late afternoon to mid-morning, males from mid-morning to late afternoon. (The Kansas School Naturalist)

The squabs, once hatched, are ready to leave the nest in a month, But the female may have already laid the next clutch of eggs over a week before; the half-grown squabs share the nest with them. The male takes over most of the feeding during this time.

Conscientious, hard-working parents. And they don't even look frazzled!

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Where the Nicomekl meets the sea

It's been a while since we visited the inner corner of Crescent Beach, adjacent to Blackie Spit. I wanted to see what was happening around the pier. Around, on, and under, really.

We found plenty to look at (in no particular order):

View from the end of the pier, looking out to sea.

"This is heavy water!"

Off in the distance, an eagle on a post.

Seaweed on rock at low tide.

Pigeon on protruding pier plank.

Gull. On post.

The pier, looking inland

Rusted out stair railing.

Light fixture.

Barnacles and mussels coat the pier supports.

Conference.

Rock, with barnacles.

A couple of boys were jumping off the end of the pier. A couple more didn't dare.

"Water for my crab!"

Sailing upriver.

Bag A Clypse. That's what it says. What it means, I don't know.

What I was hoping to find (and did find), next post.

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Fringed emerald

This green moth showed up on my wall this afternoon.

Beautifully fringed and pleated wings; click to see them full size.

It's the Common Emerald moth, Hemithea aestivaria. Its larva is an inchworm; a caterpillar that alternately folds up, then stretches out to grab the next foothold, "measuring" its path. This one will be a green caterpillar with black markings, about an inch long.

It is originally from Europe, but has come to this area. BugGuide says,

"First North American report in 1979, centered in Vancouver, B.C. and expected to spread outwards from there."

It's probably the same as the one my granddaughter is saving in a jar for me.

Front view.

They usually hold their antennae this way, turned back under the wing; the part that shows sort of looks machine-made, like bicycle handlebars.

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Underwater menu

I found a dead mussel in my dishpan aquarium yesterday morning. Dead, empty, cleaned out; not a morsel of mussel flesh left. One of the whelks is probably still digesting it.

The assorted other animals in the water get along nicely with each other. The isopods, limpets and periwinkles graze on the algae; the barnacles, anenomes and clams strain plankton out of the water; the crabs clean up the trash. But the whelks eat mussels and barnacles.

So white, so angelic, so bloodthirsty.

Whelk, showing white flesh and orange operculum.

I've been watching them; they settle on a mussel or a clump of barnacles and stay put, boring through the shell. The largest mussels are most at risk; a couple of little ones wander through the tops of the seaweed, where the snails can't reach them. The barnacles, stuck on the rocks, aren't so fortunate. A couple of days ago, three snails were working together on the largest barnacle, which now stays closed up, whether dead, anethesized, or trying to protect itself, I don't know.

A Nature Coast Marine Group (Australia) page gives a general timetable:

When feeding the whelk crawls onto the barnacle, tubeworm or shellfish and drills a hole in the calcium carbonate covering of its prey. In the case of barnacles, whelks usually attack the doors that open to allow the animal to feed. The whelk releases an acid from a gland in the front part of its foot. This softens the calcium carbonate which is then licked away by the rasp-like tongue (radula) of the whelk. When a hole has been made in the prey the whelk inserts its tube-like mouthpart into the victim and, with its radula, tears off and eats the soft tissues.

... It takes 30-40 minutes for each application of the acid then about a minute of rasping before the process is repeated. The whelk takes about 8 hours to penetrate a shell 2mm thick and can take up to 4 days to get into a larger barnacle.

My poor barnacles!

These miniature snails don't bother even the tiny barnacles: they are algae eaters.

Sitka periwinkles.

This one may have been a young Amphissa. It's just over 4mm. long. It would have been eating dead algae and other detritus.

I saw this next snail first crawling upside down on the undersurface of the water, suctioned on just as a larger snail would attach itself to a rock. It crossed the whole dishpan this way. Here it has moved to a leaf of sea lettuce.

Another algae eater.

These are a couple more residents of the mini-ecosystem: I'm not sure what they are, but I would guess some type of sponge. Alive or dead, I don't know, but they seem to provide housing for some of the smaller shrimpy things.

A yellowish, branched spongy substance, with random tunnels.

And a more rounded, purply sponge, with one hole in each "branch".

This long worm was travelling through the eelgrass and seaweed. It's a polychaete, with bristles on each foot, and a carnivore, like the whelks. It's probably eating the tiny, hair-like red worms that live in the sand.

Click on the photo to see the head structure.

And, since I don't have any starfish (nor gulls), nothing eats the clams.

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First moth of the summer

It's been a poor spring for moths; only a few tiny, flittery meal moths have showed up so far. Until yesterday morning. This pretty moth drowned itself in my birdbath Saturday night.

Maybe a tiger moth?

Big, staring eyes and an Einstein hairdo

Neatly coiled proboscis

My granddaughter, 3 years old, got Daddy to dial the phone for her so she could tell me, in great excitement, about the green "butterfly" (actually, a moth) that they had caught. "Come and see it, abuelita!" She's keeping it in a jar for me.

Looks like the moth season is finally starting.

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Seagulls, not squalling

There are such moments. Rare, though.

A quiet afternoon on White Rock beach, low tide, with full tummies all 'round.

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The pod critters

(Another dishpan aquarium post.)

Clams are monopods. So are these, ...


... but I haven't seen any around here lately.

We and the birds are bipeds, the raccoon and the squirrels are tetrapods, the leafhopper in a jar on my desk is a hexapod. Octopuses and squids are cephalopods as well as octopods; that they have to hog the numbering word, and leave the equally eight-legged spiders orphaned is unfair.

Next, we have the decapods, with ten legs. That covers the crabs, the shrimp and lobsters, and a bunch of other shrimpy things.

As their name implies, all decapods have ten legs; these are the last five of the eight pairs of thoracic appendages characteristic of crustaceans. The front three pairs function as mouthparts and are generally referred to as maxillipeds, the remainder being pereiopods. In many decapods, however, one pair of legs has enlarged pincers; the claws are called chelae, so those legs may be called chelipeds. Further appendages are found on the abdomen, with each segment capable of carrying a pair of biramous pleopods, the last of which form part of the tail fan (together with the telson) and are called uropods. Wikipedia

Simple and logical, isn't it?

The amphipods, (meaning they have feet on both - "amphi" - sides, as if they were unique in that respect) are decapods, with eight pairs of limbs, three of which are used for other purposes, eating and grasping, leaving five pairs for getting around on.

Orange-eyed amphipod from my dishpan.

Twelve legs? Who has twelve legs? That would work out to "dodecapod", but that's a geometric shape.

After that, isopods are easy. "Iso" means "equal"; all fourteen feet are similar and used for the same functions; swimming, crawling, and grabbing. Some of them are good at the grabbing bit.

Idotea resecata, the eelgrass isopod.

Holding on tight.

This little guy was dead. He died holding onto an eelgrass root. I tried to shake him off, brush him off, wash him off; he held on as if he were part of the plant. I had to cut the root to get him out of the water.

Back to the monopods again? A clamshell and a snail both fit that description. But here are our fourteen-leggers; two small isopods trying to hide under the snail.

Gnorimosphaeroma oregonense, Oregon pillbugs, forgetting about contrast.

These look almost like the "normal" pillbugs that live under my flowerpots, and are about the same size. But they zip around in the water, swimming on their sides, their backs, their bellies indiscriminately. Then they hide in the seaweed or the eelgrass, not very effectively because of their colour. On the sandy bottom, they are almost impossible to see. When I touch them, they roll up in a little ball, just like some of their land cousins.

Shell of an Oregon pillbug, a bit dismantled, with eelgrass isopod and ruler (metric) for comparison.

And we'll leave the myriapods for another day.

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Friday Skywatch

Boundary Bay, at high tide, looking southwest from Crescent Beach.

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Leaping clamshells!

Dishpan aquarium #3. (#1, #2.)

If I was surprised to see my mussels moving about, I was astonished to see the clams run. I check the three larger ones every day to see if they're still alive, then replace them carefully in an open area and watch. After a few minutes, one will extend a foot about twice as long as the shell is wide. The tip curls into the sand, grabs hold, and pulls the clam along after it, one foot length at a time, which is still quite fast, considering. In a few minutes the clam will be under shelter halfway across the dishpan.

But a couple of times, that hasn't been fast enough. The clam shoots out his foot, touches ground with the tip, and pole vaults on it, landing a good distance away. Instantly, the foot angles off to a new support, and off he goes again. Flip - flip - flip - flip - squirm, and he has disappeared under the sand.

Apparently, the technique is mainly used to escape from hungry starfish. This YouTube video shows how it's done.

Clams have to breathe and eat, but being economical critters (they make do with only one foot, for example), they use the same structure for both purposes:

I caught this clam with its "mouth" open, a rare event. Usually, it closes up as soon as I disturb the water. The two white tubes are the siphons, incoming and outgoing. The water flows in, passing the gills, which absorb oxygen. That takes care of the breathing. Cilia on the gills keep the water moving, and while they're at it, catch bits of food and push it towards the stomach. The filtered water flows on by and exits through the second siphon.

By the way, those tiny, barely visible clams I found a month ago are still alive, in spite of all the sloshing and stirring involved in my manual site-cleaning process. Occasionally I see one out for a walk on the sand. A few minutes later, it's gone.

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More critters from the dishpan

Dispan aquarium #2; previous post, #1, here.

The anemones, as promised.

On the White Rock beach, at low tide, Laurie found a piece of kelp in the waves. A blob of a pinkish, jelly-like substance stuck to it. I popped it in my bag of goodies and brought it home to the dishpan.

Freezer bags, White Rock beach

After a while in calm water, it contracted into a neat ball, spit out several mouthfuls of sand, rested a bit more, ...

... and opened up into a luscious pink and white flower.

It's an anenome, maybe the short plumose anemone, Metridium senile. It even has a cloned baby!

See the little one at its foot?

Another piece of kelp bears several smaller anemones, barely half a centimetre wide at the most. The white circles are baby barnacles, hard at work fishing for plankton; with the naked eye, I can see the merest hint of vibration at their mouths.

Peach gelatin anemone. (My name for it.)

Floating in a clump of fine threads of a green algae, I discovered this tiny white anemone. Or is it a jellyfish? It doesn't move about; just hangs there in the water, on its side. When I touch the seaweed around it, it closes up into a little ball.

I have spent hours leafing through my Marine Life of the Pacific Northwest, trying to tentatively identify this, and the next critter, with no luck. As the book says,

"More than 500 cnidarian species live in the Pacific Northwest."

And only 114 of them ended up in the encyclopedia. So I'm forced to invent my own names*, to use until I find the correct ones.

A problem with looking at these tentacled animals is that as soon as you get too close, quite a few of them close up shop. Sometimes even the shadow of the camera is enough. Touch them or take them out of the water, ditto. The only way to see them opened is to sneak up from the dark side, slowly, without disturbing their water.

This mini-critter is attached to a kelp blade. It looks rather like a small anemone encrusted in sand, except for those strange tentacles that curl around to make little loops.

Waving lassos; I'll call it the cowboy anemone.

And on that same kelp, this glassy, 1/2 cm tall fan stands motionless. Out of water, it collapses limply against the kelp, and becomes almost invisible. I think it may be a bryozoan, the Parasol, maybe.

Caulibugula californica?

The encyclopedia says about the Parasol,

"... apparently prefers low-current, often silty locales. ... Would it be noticed in high-current locales that are so often densely packed with life?"

I would answer, "No, not even at its full-grown size (3.5 cm). It's only visible when the light catches it just right.

Oddly, although it is so tiny, so glassy, so delicate, it is also tough. I have moved that piece of kelp around many times, piled it in a bowl to change the water, half-buried it in sand ... As soon as the kelp is freed, the Parasol pops right up again, with all its feathery branches intact.

Still more to come: isopods, snails, clams, and another worm.

*If the authors of the encyclopedia can do this (p.14), so can I.

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Dishpan aquarium

It all started with the worm.

About six weeks ago, I came home with a half a worm in a bag of sand. When it was still alive a week later, I blogged about it. To recap: the worm was a sandworm ("Sandy"), Nephtys caeca, and among its characteristics is the ability to survive decapitation. It can regenerate a new head or tail; cut it in half, and you may get two worms. I decided to try to keep the worm alive, bringing home fresh sea water for it, to see it rebuild itself.

All went well, at first:

Sandy, four days after the blog post, showing new growth at the broken end.

A week later; four new segments! And the worm is starting to burrow.

Every time we went to the beach, I brought back a litre or two of salt water. Other things came along with it; I had the water, and a dishpan to house them in, and a little bit of biodiversity would make the place feel more like home. I brought home handfuls of seaweed, a few clams, rocks with mussels stuck to them, a few interesting snails. And every day, I poured off half the old water, and added an equal amount of clean, new seawater.

Unfortunately, that wasn't enough. One day, the water stunk. And my poor Sandy was dead. So were a couple of snails. I changed their water completely that day, but it was too late.

But I still had a dishpan half full of live things; I couldn't just quit. So I modified my routine. Now, every day, twice, as regularly as the tide, I pour off all the water, rinse out the sand to clean out remains of meals, etc., and refill the dishpan with fresh water. We don't get to the beach every day, and I can't carry all that water, so I filter the old water thoroughly, sloshing it plenty to aerate it, and ending up passing it through two layers of coffee filters.

A lot of work. I hadn't intended to have a seawater aquarium, and I don't have the equipment. I think I need to acquire a bubbler, a filter, a good pump. And maybe a gizmo for measuring salinity so I can make my own seawater.

It's been worth it, though. I've been watching my little world; it's fascinating! I keep discovering new residents or behaviours I never would have guessed. The seaweed comes full of its own residents, and each mussel or snail turned out to be carrying at least a few smaller snails and some barnacles.

I have some 30 photos that I absolutely must share. Here's the first batch:

A tiny white crab with a face on its back.

Barnacles on a snail shell, fanning for plankton.

I learned something about barnacles; each one is an individual. Each little net (feathery legs, or cirri) is cast differently than the neighbour's. Some spread out widely, others make a narrow spoon; some fan from the base, a few stick out a long stalk, then uncurl a little scoop at the end; the nets are triangular, a half-circle, or a full circle. And each one has its own rhythm. In general, the tinier the barnacle, the faster and more often it fans, until the very tiniest seem to be vibrating constantly. A big barnacle spreads its nets more slowly, and sometimes rests for a full minute.

Big barnacle, with algal "moustache".

Hermit crabs: I brought one home on purpose. The others hitchhiked in seaweed.

Big guy, with long, cool, dotted tentacles and ...

... stripy eyes.

Big guy meets another, this one with orange legs with white polka dots.

A tiny, homeless hermit, out searching for a shell. I donated a few empty ones I had on hand. Black claws, dark sunglasses.

This little critter threatens me from a bed of seaweed. Look at the size of that right claw!

A tiny hermit in a pretty brown shell, on a torn edge of kelp. His legs are white, the tentacles short.

Same one, on a mussel. Look at the mussel's lips! That goop is mussel feces; every so often he spits out another blob.

I learned something new about mussels, too. They move about. I always assumed they stayed rooted to the rocks, just like the barnacles do. Mostly, if the large ones have a good foothold, they just shift themselves, much as I stretch and turn in my chair to ease stiff muscles. But the littler mussels will wander all over, up and down the rocks, across the sand, up the sides of the dishpan.

That's enough for now. Tomorrow, I think, the anemones.

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What made this beach button?

The tide was at its lowest; we'd walked and waded to the end of the shallows off Centennial Beach, and were walking back to shore. On the first sand bank, that one just ahead ...

... we saw this:

It was sitting like a bead on the sand, perfectly firm and rounded, about an inch high and wide, with a large hole in the center top. There was one other several metres away, but no more.


I dug my little shovel in beside it, one quick jab a good four inches down, and turned over the sand. There was nothing in it. Just sand. It didn't even squirt water at me.

There are some little castings beside the mound, and along the troughs of the nearby sand ripples. Those whitish things seem to be small snail shells. We didn't even notice them at the time, in our hurry to dig up whatever it was and get going; the tide was coming in, just behind us.

I can't find anything like this in my books, nor have I seen one like it before.

I need help. What do you think this is?

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In a handful of seaweed

Sea flea with orange eyes:

Possibly Ampithoe sp., Boundary Bay.

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Synchronized ducklings

In training:

Two by two.

"Let's try that again!"

"Look, Mommy!"

Next trick; flying!

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Hands off!

Devil's Club. Oplopanax horridus. Justifiably called, "... the meanest, prickliest, baddest plant in the forest."

It is an attractive plant; large, maple-like leaves surround a tall flower spike, which later develops into a cluster of the reddest of red berries. In its favoured habitat, the dense rainforests of the We(s)t Coast, they add a welcome spot of colour in the fall and winter.

Devil's Club, Cougar Creek canyon

Unripe Devil's Club berries.

Its other features are not quite so welcome. It's covered in ferocious spines, up to an inch long; spines that break off with a mere touch, that dig deep into the unwary hand and fester there.

Spines on the main stem, and on the leaf stalks, too.

On a flower stalk. Laden with toxin.

Even on the leaves, top and bottom.

Various parts of the plant were used by BC's native peoples as medicine, or to prevent attack from evil entities. (This last, by sympathetic magic ; one dangerous thing scares off another, or its converse; something so bad must also have an equally good effect.) It it edible, just barely; the tips of the plant in the early spring can be eaten in small quantities. Otherwise, it proves toxic, except in medicinal doses. (And even then, caution is needed.)

I was bushwhacking through a wet forest in the Bella Coola valley, years ago. The ground was littered with fallen trees, rotten stumps on top of rotten stumps, thick cushions of slippery moss, all bound together with salmonberry canes. It was slow going, and when possible, I walked above it all, using more recently fallen trees as bridges, and holding on to cedar saplings and salmonberries for support. (Salmonberry has spines, too, but they're short and soft up near the top of the plant. )

I was too high to see the stalks, and mistook a Devil's Club leaf for a harmless thimbleberry.

See, (and this is the worst thing about Devil's Club) the two plants are twins:

• They grow in the same habitat; moist banks, rainforest, stream banks.
• They grow to about the same height: anywhere from 1.5 metres to 3 metres.
• The leaves of both are large and spread out horizontally to catch the light.
• They both have white flowers and red berries.
• The leaves look alike at first glance.

These are thimbleberry leaves. Photo from nwplants.com.

And these are Devil's Club. Photo from Sierra Club.

• The leaves are even equally soft-looking. Thimbleberry leaves are soft, absorbent, and flexible, and have been traditionally used for wrapping foods or holding a serving of berries. They can pad a backpack to protect your harvest of mushrooms, roll up to make an emergency drinking cup, or serve as a hat in a sudden rainshower. And if you're ever caught in the bush without TP, they work for that, too. Try that with Devil's Club leaves! Or rather, don't.

Thimbleberry stalks, stems and leaves are always spineless.

And everything they say about Devil's Club spines is true. My hand swelled up, the spines buried themselves and festered. It hurt! For a long time. And I never forgot the lesson.

One other thing; BC's native peoples say that bears eat the berries.

"The Tlingit thought bears chewed the roots to soothe their battle wounds. The Bella Coola thought that bears ate the unpalatable fruits (known to them as "grizzly's berries") and used the thorny branches as bedding." From ZooScape.

Of course, grizzly bears (Ursus horribilis; it's somehow appropriate that they would eat O. horridus.) have fur so thick that Devil's Club spines could never reach the skin.

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Footprints on the water

It was a sunny Sunday afternoon in Cougar Creek, and the water striders were out enjoying the sunshine. In every calm pool, they scooted about, like teams of rowers in outrigger canoes.

They're hard to see, even when the light is good. They're small (about half an inch long), they're fast (up to 1.5 metres per second, or 3.4 mph.), and their colours blend in nicely with the mud and stones of the creek bed. And their shadows, usually somewhere off to the side, attract our attention first.

The shadow is distinctive; six circles or ovals with a canoe shape in the centre.

It gives the impression that the feet are round or oval pads, something like snowshoes or pontoons. This time we got some photos that dispelled that notion.

This one looks like a cheerleader with pom-poms.

Funny how the shadow looks so solid, while the disturbance in the water still lets light through.

Another strider; here the feet can be seen as a straight line, surrounded by a "bottle brush" of wavelets.

This one caught the light, creating a variegated pom-pom effect.

The last long segment of the strider's legs makes contact with the water. It is covered with tiny water-resistant hairs, angled off at about 20°, each one grooved to trap air, making a sort of cushion (or pontoon, after all) between the leg and the water. I assume that this pattern of hairs and grooves is what creates the radiating lines on the water.

The strider rows with the long middle legs, steers with the rear legs, and uses the front ones, resting on the water surface, to detect the motion of prey insects, much as a spider checks the vibrations of its web.

And here, the pattern changes:

A mating pair. Ten legs on the water. Two used to hold the female.

Cruising down the river on a Sunday afternoon,

With one you love, the sun above, waiting for the moon.

The old accordian playing a sentimental tune,

Cruising down the river on a Sunday afternoon.

The birds above all sing of love, a gentle sweet refrain;

The trees around all make a sound like softly falling rain.

Two of us together, we'll plan a honeymoon

Cruising down the river on a Sunday afternoon.

A tangle of legs in another pair.

About half of our photos showed mating striders. But it wasn't quite as peaceful as in the old song; female water striders are not easily convinced. The males want the honeymoon; guarding their mate to prevent other males from fertilizing their chosen female. But this endangers the females, opening them up to attacks from backswimmers, so they resist. (I wrote about this in "The Case of the Reluctant Brides".)

This couple was struggling.

"Don't go yet!"

In the next photo of the couple, she has broken away and is sitting on the rock, safe for now from further attentions.

Some interesting pages on striders:

Wikipedia, "Gerridae"

Bug of the Month, "Water Striders"

Flickr, by Tommok (photo plus a discussion of the leg structure)

National Geographic; "Robot Helps Show That Water Striders 'Row" on H2O"

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Cougar Creek Scramble

When we have only time or energy for a quick walk, we go to Cougar Creek Park and look at ducks. But once or twice a year, we get ambitious and visit the canyon, just a few blocks downstream. This last Sunday, we were ambitious.

Cougar Creek is a small, shallow creek, running about 5 or 6 miles from its headwaters to its outlet into the Fraser River. By now, the upper part is practically paved over; it runs under several malls and ever-expanding housing developments. It is, however, still home to several species of fish, including trout and salmon, both wild and hatchery.

Local residents have taken on the responsibility of preserving what remains; among other projects, they've cleaned up the canyon, and it has almost recovered its original character. There is a trail, narrow, rugged at times, muddy in the dips, sometimes treacherous. Otherwise, and except for the odd stray shopping cart (how do they manage to get down there?), it belongs to the wild things.

Cougar Creek, terrain map.

The Canyon is the area between the two tree icons. My Google map has more detail.

We entered the ravine this time from the downstream end, just before the creek turns to go into Burns Bog. We took the trail for a while, as far as "Big Tree",

Big Tree, about 4 metres in diameter.

then turned off to walk, instead, on the dry stones of the creek bed. At first, it was fairly easy going, and we dawdled, examining the pools for fish and insects (more on these, later).


As the ravine narrows, things get a bit rougher. We had to cross the stream bed repeatedly, from one bank to the other, as the stream meandered. The rocks we crossed on are loose; a couple of years ago, one threw me into a pool. Not this time, though. We both came home with dry feet, even.

Dry feet and scratched legs. And a couple of slivers. All along the creek, trees have come down, some recently, some decades hence. We had to climb over many, duck under others.

Duck under this one.

And this one, stopping to look at the huge fungus on the bottom.

We were confined to the banks. The bush here is like I remember it from my childhood up north, thick, tangled and scratchy.

Impenetrable

There were a few plants of Devil's Club, pretending to be harmless thimbleberry; careful what you grab onto for support crossing a log!

Checking out the Devil's Club

This tree was easy; we went around the roots, on the flat.

The Canyon is about a mile long. By the time we got to the narrow end, where it turns sharply upward and the only way out is on hands and knees*, it was late, so I cut across to the trail to save time on the return.

Partway down the trail, I learned why Laurie had opted for the creek bed; the mosquitoes were out in force along the trail. And they were hungry! Every time I stopped to look at a tree, or take a photo, or watch a bird, they attacked. They bit me through my clothes, they bit my arms and neck, they bored into my bare legs. No buzzing or whining, either. No time for that. Not with supper "on the hoof"!

I haven't run from a mosquito for years. I did on Sunday. I raced down the trail, with a cloud of savage beasts behind me all the way back to the road. Laurie came along after a bit, asking what was the matter. The monsters hadn't bothered with him; one victim at a time.

But we saw things I'd only read about. And got some good photos. And laughed at crows and watched a hummingbird. No pain, no gain.

Next post: mating water striders and a horde of caddis flies.

*A couple of times we have climbed down the upper end of the ravine. It is so steep that kids have strung a rope from top to bottom. We hung onto it most of the way.

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Do Harvestmen eat strawberries?

Or is this guy just getting a drink from a leftover slug dinner?

And I think I have recovered from yesterday's babysitting, so I'll be back shortly with Sunday's hike.

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Six red wings over Iona

Kite, Iona Beach Regional Park:

The Red Baron flies again!

And I'm babysitting in a few hours, so that's it for tonight.

Coming up in the next few days: mating bugs, a challenging hike, Devil's club, and Iona's dunes, with birds. But first, I've got to get some sleep. G'night!

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Merrily, merrily, merrily

... I do fly
After summer merrily.
Merrily, merrily shall I live now
Under the blossom that hangs on the bough.

It's open house, here, and nectar is on the menu:

Unidentified bee

There are dozens of these partying in every rhododendron shrub, from dawn to dark. They dash from flower to flower, barely staying for a second in each. Time's a wasting!

A shiny black and blue fly, resting on the moss

A tiny wasp (I think), who came to share our tea break at Tim Horton's.

A common backswimmer, Notonecta undulata.

A puddle across the street is full of these. They lounge at the surface in the sunshine, belly-up, head-down, holding on to the "skin" of the water with their toes.

They are predators, eating other bugs and even small fish (not in this puddle, though). And they are really fast; those back legs make great oars. The front ones are spiny, for grabbing prey, but the back legs and tail are feathery, like bird wings.

This one got flipped over when I moved it. Isn't it pretty?

The bees are not the only diners on my rhododendrons; here's a flower longhorn beetle.

Pidonia scripta

"Where the bee sucks, there suck I." (Shakespeare)

And with so much going on, the spiders are keeping busy. This one is a granddaughter of Fat Momma.

Achearanea tepidariorum, American house spider

One more photo, not a bug. A flower smaller than any of today's bugs; just a small blue dot in the grass.

Tiny but beautiful

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It's wasps all the way down

(This is a follow-up to my posts on aphid mummies, Two for the price of one, and The case of the pregnant mummies.)

Thanks to the helpful comments on my aphid mummies, and a generous dose of Google and BugGuide, I thought I had a handle on what is going on in my maple tree. But maybe not; one final comment uncovered the next level down.

Todd suggested the possibility of hyperparasitoidism. And of course I had to look it up.

Another aphid mummy.

First, why the "-oid" suffix?

"A parasitoid is an organism that spends a significant portion of its life history attached to or within a single host organism which it ultimately kills (and often consumes) in the process. ... In a typical parasitic relationship, the parasite and host live side by side without lethal damage to the host. ... In a parasitoid relationship, the host is killed, normally before it can produce offspring." Wikipedia

In other words, the aphid is a parasite; it lives on my maple tree, but doesn't kill it or stop it from producing seeds. The wasp is a parasitoid because it kills the aphids.

And hyperparasitoid, then? Again, from the same Wikipedia article,

"It is not uncommon for a parasitoid itself to serve as the host for another parasitoid's offspring. The latter is commonly termed a hyperparasite, but this term is slightly misleading, as both the host and the primary parasitoid are killed. A better term is secondary parasitoid, or hyperparasitoid..."

In the case of the aphid and the wasps, here's how it works; the wasp, possibly of the sub-family Aphidiinae, lays one egg inside the live aphid. She goes on to find the next aphid, and the next ...

The aphid goes on with its life for a while as if nothing had happened. But the egg hatches and the wasp larva grows, taking its nutrients from the aphid body. Eventually, after the larva has molted for the last time, the aphid dies. The larva slits open the underbelly of the aphid and glues it to the leaf, then builds itself a cocoon and pupates. The aphid becomes a mummy, hardened and brown.

Normally, the new adult wasp cuts a hole in the mummy, and leaves to start the cycle again. However, if it is found by a hyperparasitoid wasp, it in turn becomes a host.

This wasp is from a different family, the Megaspilidae. The female drills a hole through the hardened mummy case and lays one egg on (not in) the larva inside. This new egg hatches, and the larva (#2) feeds on larva #1, killing it, then pupates, emerges, cuts a hole as larva #1 would have, and heads off to find its mate.

So, was the wasp that emerged from my aphid mummy a parasitoid, or a hyperparasitoid, as Todd suggests?

Micro-wasp

I looked up as many of these wasps as I could find, and examined the photos. The closest I could get to my specimen were the Aphidius colemani. (Other similar Aphidius either did not live here or were too large) Bug Guide has a photo of one laying her egg in an unfortunate aphid, and another, whether colemani or not, they couldn't say, but definitely in the genus Aphidius.

The one I had found earlier to match mine (and perhaps a closer match that the A. colemani) was a Lysiphlebus testaceipes, also in the same sub-family.*

Both of these are parasitoids.

I found a photo of a hyperparasitoid wasp, a Dendocerus. It is similar in shape and colouring, and about the same size. The wasp in the photo has "antlers", but only because it is a male.

Dendrocerus. Image from NC State U.

Was my wasp male or female? I don't know.

So I still have a mystery on my hands. All I need to do to solve it, though, is find a male and see if it has antlers. Simple, isn't it?

*These classifications are confusing. The Aphidiinae is a sub-family, or maybe a family, in which case it should be called Aphidiidae. This sub-family is divided into tribes, one of which is called the Aphidiini. And one genus in this tribe is called Aphidius. Lysiphlebus is another at that same level.

And they prey on Aphids, of the superfamily Aphidoidea and family Aphididae.

Don't blame me; I'm just sorting it out in my own head.

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A choice of skies

It's all in the way you look at it.

Facing East:

Sky, with starling.

Facing South:

Balancing act.

Facing West:

Into a pale sunset.

Or facing down (North was a solid grey):

A few inches of water and all the sky above.

A Skywatch post.

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High temps, low cat

It's too hot. Far too hot. Today, in Vancouver, the temperature reached 25.8°C. (That works out to 78.4°F.) And here on our hill, it was even hotter; on the sunny side of the street, the thermometer read almost 30°C.

Yes, I know that's nothing. Down south, you might call it a cool day. But this is Canada! Our normal for this period is a high of 18°C (65°F), according to Environment Canada.

If this keeps up, I tell Laurie, I'm moving to Nunavut. In Kugluktuk, they're offering a nice, balmy 9 to 12°C (53.3°F) for this week.

This cat had found herself a cool spot under a car in Beach Grove:

Comfy.

She's the flattest cat I have ever seen!

Normal cat, not flat, wishing for air conditioning.

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Mugging for the camera

Goldfinch, Beach Grove:

He knew we were watching, and kept hopping from one section of the fence to the next, always checking to see if we were still with him. "How about this background?" he seemed to be saying. "Or this one?"

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Do Not Disturb

The wasteland across the street beckons us these days.

For, lo, the winter is past, the rain is over and gone;

The flowers appear on the earth; the time of the singing of birds is come, and the voice of the turtle is heard in our land; ... (Song of Solomon 2:11, 12)

(There are no turtles on the vacant lot, and old Solomon probably meant turtledoves, anyhow. And turtles hiss like snakes. But you get the picture.)

We went over yesterday afternoon to see what is new this week. It's bunny rabbits, young ones!

First bunny, with tangled fencing. As good as blackberry canes for keeping the hawks at bay.

Second bunny, pretending to be another rock. A rock with pink ears.

Following that second rabbit, we got too close to the area where the killdeers have their nest. One of them called out.

"Peet!"

"Follow me!"

We back-tracked, watching our step so as not to disturb a nest. But it seems that our path brought us closer to their hiding place; one of the birds came almost to our feet to do the distress dance.

Fantail. And look at the curve in that wing!

Eyes in the back of her head. Good parenting trait.

"Are you watching?"

Flashing those petticoats!

(She reminds me of the swinging skirts of the Jarabe Tapatío, the Mexican Hat dance.)

We slipped away quietly. Across the field, I heard one last "Peet!" And then silence.

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Floratherapy

Sometimes I think computers are conscious and malevolent. Like yesterday; I had to wrestle with one of the beasts all day and evening. Things that worked perfectly the day before were on strike, demanding all sorts of goodies I'd never heard of.

In the afternoon, I took a quick break to sit on a rug in my back yard and play with the new camera:

London Pride in bloom

Rhododendron buds

Dutchman's breeches.

Ahhhhh!

And back to the battleground.

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Guarding the nest

Eagle, White Rock, one of a pair. We saw this same couple in the same tree, last summer.

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