Nature notes and photos from BC, Canada, mostly in the Lower Fraser Valley, Bella Coola, and Vancouver Island.
Tuesday, August 31, 2010
Primary colours
Monday, August 30, 2010
Just a family afternoon
I spent the afternoon and evening at a family party in Chilliwack. Picnic in the chapel garden, with the sun playing hopscotch with grey clouds; just a bit chilly. Summer has ended.
Afterwards, we sat around the living room to watch a slide show of my daughter's and her husband's photos from Italy; beautiful! They're wedding photographers, and very talented. And Italy! The buildings, the colours, the light! Just amazing! I came away half-envious, completely inspired.
Some of the photos we saw, the ones from Cinque Terre and the Amalfi coast, and from Venice, are on their blog. My daughter writes,
It is impossible for us to convey the way your stomach lurches at the steepness of the rocky outcrops, the heat and humidity on your skin, or the tightness of the curves of the (crazy narrow!) roads. We were amazed at the resourcefulness of the local people in finding the space to grow beautiful gardens and carry on their regular lives on the narrow terraces. I hope you can see a glimpse of all this in our photos.Go check them out! Here's the Amalfi coast. And Venice.
Sunday, August 29, 2010
Saturday, August 28, 2010
Full tank
Cookie, the smallest crab. She grew up from a tiny thing, barely visible, and is now almost an inch across. Here, she's sitting still in the sea lettuce, getting ready to molt.
I watched her yesterday, grooming herself. As usual, she picked at invisible bits of stuff on her legs, wiped her mouthparts, scraped her pincers. And then -- imagine this -- one of those big pincers grabbed her eyestalk and yanked at it. She scratched away at the eyeball itself, vigorously. I was wincing, just watching her. She finished and went back to cleaning her legs, perfectly contented.
A Japanese nassa. There are a half-dozen or so of these; they wander around constantly, apparently ignoring the crabs and hermits that walk over them. Nothing seems to eat them.
Spot, a medium-sized grainy hand hermit. I like the pattern on the shell he has chosen; it's covered with barnacle scars, giving it a polka-dot look.
This is the backside of the largest hermit, "Barney"; you can just barely see one of his red antennae at the lip. When I brought him home, the barnacle was alive and feeding. Other hermits, the small, fast hairy hermits, ride on his shell often. Whether it was them or the snails that also hitch a ride that ate the barnacle, I am not sure. Now that the shell is empty, it has been taken over by a small green worm, just visible at the bottom of the barnacle. Occasionally, it stands up and waves around in the water, searching for food.
The largest of the anemones, about an inch and a half long.
These are some sort of a sponge, encrusting sea lettuce. (Update: now identified as Violet Tunicate, Botrylloides violaceus.) Each separate opening (look closely) is like the top of a little, pot-bellied barrel. Almost every one seems to be attached to the next, marching around and around in orderly lines. The pattern is more apparent in this next one:
Some of these are pink, some deep red, a few white.
These were very tiny, and almost completely transparent when they came home with me in some seaweed. They've grown; three are still transparent, but this one, the biggest at half an inch, is developing a pattern. I think it is a coonstripe shrimp. If so, they could grow up to 6 inches long in the wild, not so much here.
They drift around, seemingly without effort, even going against the current. Nothing bothers them; they even sit on the crabs' backs without getting grabbed at.
Two of the hermits watch a big flatworm engulfing a snail. This I had to see to believe. The flatworm oozes over the snail, and squirms around, trying to detach it from the glass surface. The snail holds tight; as long as the lip is on the glass, the flatworm can't get in to kill it.
The worm backs off:
... and tries again. This snail is ridged with jagged "wings"; it took several hours of persistent tugging for the flatworm to win out, probably with some cost to its "skin". We watched, off and on. So did the hermits. (The flatworm doesn't attack them, but were they worried?) Eventually, when I came back to check, there was no sign of either flatworm or snail.
Two days later, I saw the flatworm with a snail again, this time a smoother Batillaria. And the battle was taking place on the sand; the worm was having no problem wrapping itself around the snail. While I watched, with the snail completely overpowered, the flatworm started flowing away, dragging the snail down into the sand with it.
I've begun to bring home snails, mostly the invasive Batillaria, to feed the flatworms. There are two big ones, several tiny ones, all of them hungry.
One more critter. This one is tiny. The fresh seawater I brought home for the tank was silty; I let it settle out before I used the water. About an 8th of an inch of sand remained. Before I dumped it, I took another look. Something moved; something I couldn't exactly see; I just had the impression of movement. I got the lens and looked. Yes, something was moving, in one spot. Not a copepod.
I looked at it through the microscope. Wow! This was something I'd seen in the Encyclopedia and thought, "How strange!" I didn't expect to get to see it.
Look at the centre of the photo. Do you see a dark circle? Look closely. Do you see a pinkish thread coming out of the circle on the right? There are two; one to the left, almost invisible.
It's a worm, possibly a jointed three-section tubeworm, Spiochetopterus costarum. We see these on the tide flats at Boundary Bay, sticking up about an inch above the mud. The two tentacles, of course, are never visible at low tide, just a whole bunch of little matchstick tubes. There's a good photo of a feeding worm, here.*
The two tentacles wave to and fro; I saw bits of stuff touch them, get caught, then slide down the tentacle into the tube mouth. Sometimes the tentacles themselves are retracted, probably to be cleaned off; then they extend into the water again and go back to waving about.
*That's a good site for marine life; here's the index page.
Friday, August 27, 2010
Pocketful of aphids
Now we've found them in Cougar Creek park, and well within reach.
I had found references to them on the web; Wikipedia has an article about them. They're Bedegaurs, or Robin's pincushions; galls produced by a small wasp, Diplolepsis rosae, probably. Although there are other wasps that cause the rose to wall them off in galls, those are "normal" galls, smooth-skinned. Good to know, but I had to see for myself.
I broke off the largest ball, getting well scratched in the process. The gall was cool and dry to the touch, and quite firm under the fiber coating. (Wikipedia says the filaments are sticky; I didn't notice this. It felt more like a dry moss.) It had a mild apple (or better, apple shampoo) scent, quite pleasant. I stuck it in my pocket and brought it home.
I laid it on my kitchen counter, and aphids spread out around it. I probably had aphids in my pocket, too. It wouldn't be the first time.
With a sharp knife, I sliced the gall down the centre. It was surprisingly easy; I've cut other galls and found them woody. This was like slicing a carrot. In the white centre were a number of smooth, round holes, each with a white larva coiled inside.
The wasp that laid the eggs in the rosebud was a tiny, black, parthenogenic female. The larvae hatched a week later, and began to feed. The rose responded by surrounding each larva with large food cells, replacing them as needed to feed the growing invaders. In turn, these were walled off by smaller cells (the green layer in the photo), and then by a thick growth of branched fibers.
The ones we found at Crescent Beach were a deep pink; they were ripe, then. They start off green, turn pink, dry up and turn brown. They stay on the rose until spring, when the adult wasp burrows its way out.
I found only one species of larva in this gall. But there could be others:
A gall provides the developing gall wasp with a safe refuge for the most vulnerable stage of its life-cycle, however, many other wasps have found a way penetrate this defence and parasitise the larva(e) within. Some of these parasitoids use their long, hardened egg laying tube (ovipositor) to bore into the gall and lay an egg on the helpless gall maker. Collect a Bedeguar or robin's pincushion gall before the autumn and keep it somewhere cool. In the spring, you will see at least one species of parasitoid emerge instead of the gall maker. These wasps, such as Eurytoma rosae are beautiful, metallic insects with long ovipositors. (Wikipedia)
Thursday, August 26, 2010
Wednesday, August 25, 2010
International Rock Flipping Day, 2010!
Mark your calendars: IRFDay this year will be the second Sunday in September; Sept. 12. That gives us a bit over two weeks to find a suitable source of rocky material.
If you're new to Rock Flipping, this is what it's about (from last year's announcement):
Rock Flipping Day was started by Dave Bonta and Bev Wigney in 2007. The idea is simple; in Dave's words,
"...we pick a day for everybody to go outside — go as far as you have to — and flip over a rock (or two, or three). We could bring our cameras and take photos, film, sketch, paint, or write descriptions of whatever we find. It could be fun for the whole family!"
37 bloggers joined in that first September.
"On 9/2/2007, people flipped rocks on four continents on sites ranging from mountaintops to urban centers to the floors of shallow seas. Rock-flippers found frogs, snakes, and invertebrates of every description, as well as fossils and other cool stuff."
And here's a quick rundown of the procedure:
- On or about September 12th, find your rock and flip it over.
- Record what you find. "Any and all forms of documentation are welcome: still photos, video, sketches, prose, or poetry."
- Replace the rock as you found it; it's someone's home.(More on this, later.)
- Post on your blog, or load your photos to the Flickr group.
- Send me a link. My e-mail address is in my profile, or you can add a comment to any IRFD post.
- I will collect the links, e-mail participants the list, and post it for any and all to copy to your own blogs.
- Tweet it, too. Use the hashtag #rockflip.)
Again, as we said last year, remember:
One thing I forgot to do in the initial post is to caution people about flipping rocks in poisonous snake or scorpion habitat. In that case, I’d suggest wearing gloves and/or using a pry bar — or simply finding somewhere else to do your flipping. Please do not disturb any known rattlesnake shelters if you don’t plan on replacing the rocks exactly as you found them. Timber rattlesnakes, like many other adult herps, are very site-loyal, and can die if their homes are destroyed. Also, don’t play with spiders. If you disturb an adjacent hornet nest (hey, it’s possible), run like hell. But be sure to have someone standing by to get it all on film!(Last year, Will Rees, in snake country came across a cottonmouth. Good thing he was cautious and alert!)
(From Dave)
and,
A reminder to all rock flippers that they (the rocks) should be flipped back into place. If there are critters underneath, don't place the rock back on top of them, move the animals to the side, replace the rock and let them scurry back.Conservation Maven discusses a study on the effects of rearranging rocky habitat:
(Thanks, David Steen.)
So, be careful, be aware, and leave no traces of your visit, and all will be well.With an elaborate experimental design, Pike and his team were able to show that altering the position of rocks negatively impacts reptile habitat by modifying crevice microconditions that species prefer.
The study also demonstrated that the impact is easily reversible by restoring the rocks to their original position.
What will we find this year?
Monday, August 23, 2010
Got boots?
Hi, Susannah
I’ve been reading your blog and I thought that you and your followers would be interested in this charity campaign that will raise money for local wildlife. It won’t cost them a penny and will only take up a few minutes of their time.
The Wildlife Rescue Association of BC is one of the recipients of the Keen Canada campaign Boots Give Back. For every photo of boots uploaded to its website at www.keencanada.ca/BootsGiveBack/Donations.aspx, the outdoor shoe specialist will donate $5 to one of the four listed charities, including the Wildlife Rescue Association based at Burnaby Lake.
The promotion runs until October 31, 2010, and with WRA as the only BC-based charity recipient, the more photos your followers upload, the more money the WRA will get to carry out its vital work.
The WRA has been carrying out wildlife rescue and rehab since 1979. Last year the organization cared for more than 3,000 injured, orphaned and pollution damaged animals, the majority of them birds.
Each person can upload a photo of their boots in action as many times as they want. Keen only ask that participants upload just one photo a day and use a new photo every time. You don’t even have to be wearing Keen footwear. Any brand of boot, shoe, sneakers, clogs and even flip-flops will do.
As well as raising money for the WRA, participants stand a chance of winning free prize packs which include boots, bags and socks.
For more information about the WRA, go to www.wildliferescue.ca
Upload your photos at: www.keencanada.ca/BootsGiveBack/Donations.aspx
Thank you for your support.
Yolanda Brooks
Communications Coordinator
Wildlife Rescue Association of BC
I went to their site, www.wildliferescue.ca , and "toured" their facilities. It is very similar to O.W.L., except that they rescue animals and small birds as well as raptors. I recognize the old house they use as an office; drove in there once, years ago, I can't remember why now. But someone there was talking about ducklings; it seems that people bring them in, thinking they're abandoned, not realizing that the parents know where they are. And sure enough, they still have special housing for baby ducklings!
Now, I'm off to look for shoe and boot pics.
*Update: Found one: with a car ahead of me in the lineup at Bull Canyon, waiting for the escort car to lead us through the fire zone.
Hard at work ...
I think this is a ring-billed gull:
And this would be an angry swan:
And a bittern:
Well, I never get to see a bittern, even when other people find them right where I've just been. So I may as well make do.
Sunday, August 22, 2010
In the holdfast: feathers, spines, eyes and ... mustaches?
I always wade in, looking out at the deeper water, where the kelp grows. I can't go there. The swaying forest with its multi-species community is always just out of reach.
But at high tide, on windy days, the tables are turned. The waves rip up boatloads of kelp and eelgrass, roll them up like carpets, and toss them on the dry shore for me to poke at. I search the eelgrass for isopods and snails, the kelp for bryozoans and flatworms, or maybe even a nudibranch or two. This week I left the blades of kelp alone and we collected small holdfasts.
A holdfast looks like a root mass, but it doesn't gather nutrients. It's function is to hold the kelp down. At the far end are the long fronds, and the floating bladders; without a good anchor, the kelp is at the mercy (none) of the waves. The holdfast is tough and strong; it grabs onto rocks at the bottom, where it may stay for up to seven years. It's an ideal hiding place for small creatures, an interface between sea floor and live plant, a food source and a hunting ground. I wanted to see what lived there.
At home, I dumped my holdfasts into a bowl of fresh sea water, and gently pried and cut them apart. (Even the thinner stems are as tough as green wood.) Quite a few dead amphipods and skeleton shrimp floated off; it had been a rough trip, from sea floor to rollers to dry shore and sunlight, then to a plastic bag in the trunk of a car. And the centre area, inside the teepee of "roots" was full of broken barnacle shells, the barnacles eaten away.
But then the worms came wriggling out. First, the polychaetes:
There were quite a few of these, mostly small; under a couple of inches long. And another few scale worms, which I had not seen before.
Look at the upper end: each scale is like a sequin, circular. In these, one arc of the circle is black, which makes the pattern down the back. It is the same species as the one above, though.
And look at that little tentacly thing. That's what held me up; I couldn't identify it.
I looked for others in the holdfasts, and thought I saw a tiny one like this, but with a stalk. I missed it, trying to fish it out, and never found it again. But there was something similar, fixed on the holdfast:
What else? There were a half-dozen mussels jammed in between the "roots", umpteen sand-grain-sized, black snails, many little brown isopods, several clams:
And loads of tiny green sea urchins:
Sea urchins thrive on kelp, in such numbers that they are capable of killing an entire kelp forest if not kept down by other predators, such as sea otters.
Both sea otters (Enhydra lutris) and sea urchins (Strongylocentrotus spp.) play critical roles in the stable equilibrium ecosystem. Sea urchins graze kelp and may reach population densities large enough to destroy kelp forests at the rate of 30 feet per month. Urchins move in "herds," and enough urchins may remain in the "barrens" of a former kelp forest to negate any attempt at regrowth. Sea otters, playing a critical role in containing the urchin populations, prey on urchins and thus control the numbers of kelp grazers.
From NOAA.
I almost forgot: there were also at least three flatworms, so tiny they were just pale brown specks that wandered around when I put them in a plastic cup with a few teaspoons of water. They're in the tank, now; competition for the two big ones that were already there.
*Reminds me of Yosemite Sam.
Saturday, August 21, 2010
Tiny, spiny starfish
In the meantime, isn't this the cutest starfish ever?
It's on a piece of dead eelgrass and a bit of kelp. And it's under 1/4 inch point to point.
It isn't from the holdfast; I have a spare water container, for filtering used water through sand and airing it. I add green stuff from time to time, for the clorophyll; when it dies, I take it out and dump it on my compost. Luckily, I checked it first. I don't know how this starfish got there.
It's very much alive; while I watched, it crawled off the eelgrass onto the kelp. And now it's in the main tank, hidden in the sea lettuce.
Friday, August 20, 2010
Killdeer and a roll of eelgrass
I wanted a couple of things from the beach; some fresh sea lettuce for my aquarium critters, and a fair-sized kelp holdfast, just to see what it might contain. Each kind of seaweed harbours different organisms, and the holdfast, attached to the sea floor below the intertidal level, would probably be home to critters we don't usually see, even at really low tides.
Laurie untangled a few for me from a new eel-grass and kelp roll. He had to get out his knife to cut through the stipe on the largest. I bagged them up and brought them home.
And they were full of goodies! It has taken all afternoon and evening to sort through everything. I'll have the first of the photos tomorrow.