Wednesday, December 25, 2013

Christmas owls

Merry Christmas!

At the beginning of December, I came out to Boundary Bay to see if I could get bragging rights to seeing the first of the snowy owls.  The skies were clear and daytime highs were -4, making for some impressive views out to Mount Baker.


It was cold enough to freeze the mid-to-high tide lines to a slushy layer, giving the fantastic illusion of a frozen sea.


Maybe because it was too cold for the voles to come out, or maybe the birds don't like the dry frigid air blowing past their eye balls, but owls of any sort were nowhere to be seen, and only a few hawks prowled the marshes.
Cooper's hawk


Great weather for our dog

Three weeks later, and throughout most of the country, the weather has gotten colder.  Here, on the west coast of BC, it has gotten warmer.
http://www.wunderground.com
The west coast of BC was one of the only places hospitable enough to go birding today in Canada.  The skies were overcast in our part of the world, but dry.
Great Blue Heron

Northern Harrier

Trumpeter Swans

A Northern Harrier, munching on a carcass thrown over a fence by a photographer (not me!)
 And the highlight of the trip, seeing the snowy owls.  The pair were a bit distant, hanging about on the rooftop of a building nearby - one of the last places I'd look - but the best technique to finding rare birds is to look where other cameras are aimed.



The ever-laughing snowy owl

The short-eared owls made an appearance today as well




Monday, November 11, 2013

Pest control without wasting life

We maintain small planters in which we plant salad greens every spring.  Despite our best efforts at growing them, we almost never get a chance to harvest them.  In a span of a week, the leaves of our veggies will go from solid green leaves to being polka-dotted with evidence of a caterpillar infestation.  The safest way of exterminating the pests while keeping the veggies edible is to peer underneath the leaves with holes, and pick them off manually.  Why should such lives be wasted?  Fortunately, there's no shortage of predators to feed them to, and it alleviates my guilt that I'm killing for the sake of killing.

Eratigena atrica - the giant house spider

An odd thing was that this single web had a visitor hanging underneath.  The one below didn't seem too interested in the caterpillar.  But they tolerated each other for several days.


I loved her bluish tinge, and the red lipstick she put on just to look good.  I can't imagine what creature she had eaten to dye her fangs red.
Eratigena atrica
Araneus Diadematus - the cross spider

With about 30 caterpillars, many of the spiders got a double helping.

Araneus diadematus

Platycryptus californicus

Caterpillars aren't the only pests around though:

Spittlebug - these can be a serious crop pest in larger numbers, but these ones seem to be satisfied with the English Ivy hedges, which I'm more than happy to let them suck on
 In the fall, for a few brief weeks, mushrooms spring up out of our wood mulch.  I dabbed a bit on my tongue this year to test its toxidity...no tingling.  But they were still too wormy to be appetizing.  I waited too long, once again.

A single bolete mushroom was home to probably 40 of these maggots

The spiders appreciated this late-fall meal, a time when there were few other insects wandering about.

Eratigena atrica


Sunday, November 10, 2013

Christmas cactus, a month earlier than normal

With the extraordinarily bright October we had, I would've expected a late blooming of our cactus this year.  In fact, this is the earliest it's ever bloomed, three weeks earlier than last year.  Two flowers are already about to fall off.


 
No new leaves this year.  Compare it with the 2012 photo.

Being the rebel that he is, this little guy (his gender should be clear to anybody who sees the pollen that he's dropped all over the floor) likes being dormant during the summer, and is most active in the winter.

As per tradition:

Maybe his lack of growth is his way of communicating to me that he needs a new pot.  Without any new growth, his existing leaves will continue to droop.  This year, two of his flowers are already growing right on the floor.

Monday, June 24, 2013

Reaching the boundary

As the planet experience's this year's supermoon, the tides swing in the greatest direction.

Saturday's tide was a low 0.4 metres.  For the tidal flats at Boundary Bay, this meant we could walk a kilometre before hitting the water's edge, or a mile out to reach the cairn marking the Canada / US International Boundary Survey Monument.



On the way out, we saw beds dense with live sand dollars.
 
The tube feet and spines can clearly be seen here
 In the eel grass beds, I saw this fish with bulging eyes.  I have no idea what it could be.

I used to think of anemones as a rarity in lower mainland beaches.  Today, I saw more species of anemone in a single day than ever before on a beach.
Anemone species 1, budding.  diameter about 1cm

Anemone species 2 - a burrowing anemone. Diameter 4 cm
Crabs were abundant.  Crabbers were out in force with their hip waders and tongs.

On the way out to the cairn, I saw several metal posts positioned horizontally.  It is an oasis of sorts for the creatures that need solid footing.

Anemone species 3 and 4 on some metal structures at the cairn. Diameter about 15 cm
Crabs have amnesty when it comes to international boundaries. This one was found on the cairn, which marks the US/Canada boundary
 I used to think that a cockle's natural place was buried deep within the sand, like other clams.  I saw enough filter feeding right off the surface of the sand at Boundary Bay to make me re-evaluate this perception.
 
Species #5, in the fast flow of the outgoing tide. Diameter about 3 cm
I also saw a midshipman for the first time.  They don't have the wide head of sculpins, and the rays on their fins are not as pronounced.
A plainfin midshipman, a first for me.
Here it is, burrowing itself in the sand.

Boundary Bay hosts quite a few different habitats - the mud flats, the sandy bottoms, eel grass beds, and a solid hunk of concrete.  There are still a number of low tides left this summer...many discoveries await to be found.

Sunday, June 9, 2013

Crabbing at Boundary Bay

The last time we visited Boundary Bay, I did see a few small dungenous crabs in the water, but we spent too much time in the shallower tide pools to look for the catchable ones.  Yesterday, we tried to get to water's edge by low tide (noon) to catch something for dinner.

It was just over a kilometre of walking to get to the water's edge.
https://maps.google.ca/maps/ms?msid=210247271623531636657.0004deac4ee208b13d515&msa=0&ll=49.010923,-123.0287&spn=0.012034,0.033023

We arrived just as the tide was ascending, but still saw many crab in the knee-deep tide pools.  Many that I found were embraced in  courtship:
 
A male finds a female who is suitable for mating, and grabs her tightly.  He locates a suitable female through chemicals in her urine, which signals that she is about to moult, or discard her old shell.  The female is only receptive to mating when her shell is soft, so the male will carry her around for a few days, fighting off potential suitors, and waiting until she moults.  He will further protect soft shell from predators.


Even after pulling him out of the water, he remains firmly grasping his much smaller partner.

I didn't see many nudibranch this time, but found other soft-bodied invertibrates, like this dead lion's mane jellyfish.

Most of you have never seen a clam move, but they're terrific diggers, considering they only have one appendage.

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Sunday, June 2, 2013

Bounding about a bay

A few weeks ago, a friend convinced me that we should go to the beach.  As I hadn't done that in a while, and low tide was conveniently in the afternoon, we decided to head to Boundary Bay.

The low tide measured about 1 metre, which in the tidal flats of Boundary Bay means about a kilometre to walk out from the beach out to the water's edge.  That meant plenty of tidal pools to explore.

Eel grass provided habitat for many animals, including nudibranchs (the first time I've seen them in tide pools)





Anemone (1cm wide)

A mass of eggs of something
As we made our way out to the water's edge, we saw more and more sand dollars.  Most of you have probably seen them either at the beach or a souvenir shop - a white, chalky disk.

A sand dollar test on the North Coast Trail
This is merely the "test", or skeleton, of a sand dollar.  Sand dollars are relatives of sea urchins, and like urchins, are equipped with spines when alive.  By the time most of them wash up on the shores of beaches, the abrasive sand scrubs off most of the spines.

Live sand dollars will live where the water is fresher, in the lower portion of the intertidal zone.  It was here that we found living sand dollars.



With the spines, one can easily see the resemblance to sea urchins.  However, the spines are tiny and much more densely packed than that of an urchin, and they are used more for digging than protection.  With a coordination similar to that of a sea star (sea stars, sea urchins, and sand dollars  are all in the echinoderms phylum), the sand dollar coordinates its spines and tube feet to position itself nearly vertically in the sand, half buried. It catches small particles of food as it floats by, and moves them towards its central mouth.

Other critters were much more difficult to observe without actually catching them.

Shrimp
As we walked through the tide pools in our bare feet, we could easily see the fish darting away from us.  With their camouflage, they became invisible as soon as they stopped moving.  However, we took advantage of their escape behaviour to capture them.  Some would squirm into the shade of our feet each time we took a step.  After we got over our delight of them tickling our feet, we could trap them against our feet and our cupped hands.

Only a flounder as small my fingernail could stick onto a vertical surface

The sculpins were likely tide-pool sculpins, a common species that grows to a maximum size of a couple of inches.  As for the flounders, I knew that they start off life free-swimming in the plankton, whose eyes migrate to the same side of their head as they settle on a life on the sea floor.  I didn't know how large they are when this eye migration happens.  Internet research says that in one species, it migrates at around 1/2 of an inch in size, which matches the size of this flounder, so it's possible this is really a baby flounder and not an adult (I don't know of flounders whose adult sizes are this small).


The largest sculpin we caught was maybe an inch long

My friends and I quite thoroughly enjoyed our day exploring at the beach.  The abundance of life in what one might think is a barren mud flat will definitely bring us back.

Saturday, May 11, 2013

Charlotte's Web

One of the first stories of wildlife I remember reading was Charlotte's Web, by EB White.  The unlikely friendship of a pig and a spider reassures the young reader that even when one thinks one is alone in the world, one really isn't.

Spoiler alert for those who haven't read the book, but enjoy reading books for youth and might one day read this one:

The story finishes with Wilbur, the pig, finding Charlotte, the spider, missing, and astonished that her offspring fly off into the wind with nary a concern for their future.  With glee, they catch the wind with their threads, disappearing into the atmosphere.

Araneus Diadematus is Charlotte.  She is the most abundant orb weaver in Canada who can claim responsibility for spiral (orb) webs larger than 30 cm.

Each day of their lives, as long as the weather is dry, they spend 30-60 minutes building a web in the dawn hours.  Typically, they'll rebuild in the same location, but they will change locations to suit food abundance and personal safety.  As they reach maturity, their mobility decreases (they are poor walkers) so they spend the final months of their lives in the same home, under a man-made ledge or a cluster of leaves in a hedge.

In the dark nights of fall, the now heavy females then make one final pilgrimage to find a nesting spot for their eggs.

October, 2012
She is gravid - her abdomen is full of eggs.  After laying her eggs, her abdomen will shrink to about a fifth the size - the size of her cephalothorax (she will look similar to a male).  She will guard her eggs, but ceasing to build any webs (a good nest site is not necessarily a good web site), will eventually starve and die.

On a spring day, about 6 months later (as was the case for these), the warmth and dryness will trigger her eggs to hatch.  Thousands of tiny yellow bodies will cluster together for a few days while they get a bearing on life.  Then one by one, they will crawl to a relatively high point where they will release a thread of silk, allowing it to be caught by the wind, and be ballooned off towards new lands.
Each one, with legs outspread, could fit inside the 'o' on your screen.
At least six eyes are visible.

Ballooning spiderlngs have been witnessed, kilometres-high in the sky.  They are equivalent to atmospheric plankton, going where their currents take them.  This effective dispersal strategy typically makes them the first arrivals to any newly terra-formed volcanic island, though they may need to wait a while for food to arrive.

As soon as they can walk, they know how to spin a web. Their instincts lead them to build their first web with a technique identical to the last web they will build.  There are no practice webs, no "I was feeling lazy so this is the best I could do" webs, no bragging about "this is my best web, let me Facebook this".  No emotional excuses for doing what they need to do to survive, to propagate their species.  They build webs, simply because they are spiders.

Monday, April 1, 2013

Bald on the beach

On the way back home from a grocery run one afternoon, we saw a large convocation of eagles on the beachward side of the roadway.  We pulled over, and witnessed about 30 bald eagles in the midst of a frantic feast (though wild animals do tend to always dine in degrees of franticness).
Taking off with the bounty




With nearly a dozen eagles permanently guarding what remained of the food, another dozen or so sitting on nearby perches, and another couple dozen or so in the air flying in, grabbing bits of food, and flying off, and another few dozen or so in trees savouring their meal, there were perhaps 60 eagles in the vicinity.

Latecomers


It was only after about 10 minutes of observation that it became clear to me what they were eating - discarded salmon heads and backbones.  A fisherman had dumped them on the beach, to the enthusiastic glee of the many eagles.

Giving chase - entering the mad foray surrounding the pile of salmon carcasses might require boldness only the tenacious youngsters or the more senior adults possess, but intimidating another eagle to drop its food is something anyone can do. One needs to consider the ocean-bound scavengers, however, such as the seal in the foreground.

Onlookers