Misumena vatia

Warning! This post contains photos of spiders. If you are uncomfortable about that, as I used to be, I suggest you read some posts about baby cows or cats instead.

A couple of weeks ago I was inspecting the mock orange bush I'd bought for my mom a few years ago - it's one of her favourite flowers, and my grandfather had a lovely specimen growing in his yard when I was a child. I bent down to sniff a particularly lovely blossom when I noticed it was occupied!

This crab spider, sometimes called the goldenrod crab spider after the flower it normally lives in, or more accurately Misumena vatia, is a fascinating little creature. It produces a yellow pigment that it stores next to the surface of its skin, allowing it to blend in quite spectacularly with yellow petals, where it waits for its prey. However, if the spider manages to find nicer real estate on a white flower, it can get rid of its yellow pigment, reverting it to its natural white colour. It's like a chameleon spider, but with fewer colour options.

Its strategy seems pretty successful, because a few days later I checked back on it to find that it had snared a little bee.

A bit sad because I love bees, but I try to remember that spiders need to eat too! And you have to admire how this one manages to find its dinner.

Salt marsh

This week, we've been working out on the salt marshes off Westham Island. A salt marsh, in case it isn't obvious, is the upper part of the intertidal zone where salt-tolerant plants such as worts, sedges, and rushes can be periodically covered at high tide. In the delta of the Fraser River, the marshes and mudflats extend out for probably a couple of kilometers at least. We've been working with a government biologist, counting different types of native vegetation out there in order to assess how much the marsh has eroded over the past thirty years - and the answer seems to be a lot, in some places. From what I understand, the erosion of the marsh is mainly due to rising sea levels and over-grubbing by snow geese.

It's muddy, dirty, exhausting work - it's a 45 minute slog through the mud and a short canoe ride across a channel just to get to the site, and then we're on our knees in the muck all day getting poked in the eye (or nostril) by bulrush stems. But the sun is (usually) shining, we can see all sorts of birds (harriers, yellowlegs, sandpipers, bald eagles, swallows, wrens, herons, etc), and there's something about working outdoors, especially by the ocean, that really connects you to the planet. Measuring the workday by high tides and low tides and sun and rain makes me feel like I'm remembering something more elemental that I'd forgotten along the way. And the landscape is beautiful - I find it really interesting to see the different vegetation zones change as you move away from land, as different species adapt to different water and salinity levels.











This is prime real estate as far as eagles are concerned... this pair built their nest on an old navigation tower, and are raising two young that are about to fledge. This particular site comes complete with adjacent tower (excellent for stretching your wings and letting the wind take you off), multiple perch sites, breathtaking views, and even a small live tree growing out of the corner for shade.


Coyote?


Mallard nest.


A hanging marsh wren nest, woven around and suspended by cattail stalks.






Our accompanying government biologist suspected this was a harbour seal placenta/birth sac... and NOT the plastic bag we all initially thought it was!


Tomorrow is our last day working on this project, and I'm looking forward to (hopefully) a more relaxed week of bird counts next week!

The British invasion

I started a new job this week - it's going to be a hodgepodge of things, I think, but all conservation-oriented, and with hopefully not a few bird surveys. For the past two days, however, we've been mapping Spartina grass on the Roberts Bank mudflats near Tsawwassen, BC. Spartina is an invasive grass from England that's been found up and down the western coast. Like all invasive species, it seems, Spartina spreads rapidly and is a pain in the butt to get rid of, outcompeting local plants and decreasing habitat for marine invertebrates, fish, and birds.

Roberts Bank is a very alien, very magical landscape. Walking toward the water from the dikes, you wade through a few metres of vegetation before coming out onto a muddy soup, which lasts another few metres. Then finally the ground hardens, and what looks like a prehistoric or lunar terrain emerges with cracked mud and channels and pools everywhere that the tide has formed. The oozy mud under the pools and rivers is also strange... there's a thin brown surface layer, but the sludge below is a soft black colour and actually feels really lovely on the skin.











Sadly, I couldn't bring my beloved SLR and 200 mm lens out in the muck with me, which was disappointing because I saw so many amazing birds that I just couldn't capture with my point & shoot. Of course there were gulls and swallows everywhere, and little sandpipers that were too far away for me to identify. There was also a small family of killdeer that would shriek and suddenly lift off if we got too close to them, and tons of herons and eagles doing flyovers. The first morning, we also saw a Northern Harrier swooping over the shore grasses looking for a snack. I also identified my first Caspian terns, and solved a bit of a puzzle - Davis and I had been hearing their strange raspy scream all over Richmond but we were never able to get a good look at them to figure out what was making that noise. Mystery solved!

If you roll over the images there should be some text popping up - the pictures were just so cruddy in the first place that I didn't want to clog them up with too much writing. Okay so the rollover thing doesn't seem to work. In the first picture, there are some Caspian terns mixed with gulls in the foreground - the terns have a black crown and a bright red beak. In the distance, what I initially mistook to be a fleet of small sailboats is actually a bunch of great blue herons, fishing out in the shallows. In the second photo, the flagged plant is that dastardly Spartina, and a killdeer.