January 2009 – Page 4 – Seabrooke Leckie

Today at Kingsford – Birds on the lawn

So, remember back in the summer how we stopped mowing our lawn? We ended up getting a lot of weeds and wildflowers sprouting up. I liked it, I always like the variety of flowers and colour, and I think an “unkempt” lawn is nicer than a manicured one. In town there are often bylaws against it, but out here one can really do what they like with their property, except for anything that might affect water or other common resources (which can be good or bad, depending on what’s being done and whether you’re the one doing it).

Turns out, the birds liked it better too. Yesterday we had a whole pile of snow, which continued to fall for most of the day. Our feeders were inundated with birds. The nyger feeders were overflowing, with all spaces filled with hungry beaks and more waiting in the wings. Some individuals tried out the suet feeder or ventured onto the platform feeder for the sunflower seeds and millet.

And then there was this opportunistic flock of birds, who discovered the weeds poking out of the snow in the lawn, and started availing themselves of the seeds still clinging to the dead stems. The flock consisted of goldfinches, siskins and American Tree Sparrows, an interesting mixed group. There may have been a couple dozen out there at its busiest. I was glad we hadn’t mowed the lawn.

Recent news – Scientists reading minds

I thought this video was just too cool not to share (the embed code doesn’t work, so you’ll have to follow the link – sorry, WordPress doesn’t allow Flash or Java code). I saw this on 60 Minutes last night. The short of it is that using brain imaging equipment and software, scientists are starting to be able to “read” minds. They have determined that certain neurons always fire in the same pattern when thinking about specific things, and so by looking at your brain scans, they can compare those to known patterns to determine what you are thinking about.

The project is still in its infant stages, where they know, for instance, the difference between “screwdriver” and “apartment”, but are limited to a small list of words they have mapped. Right now they can’t discern complex thoughts, but it seems it’s only a matter of time – a little like the human genome project, a map of human thought is a big, but not insurmountable task, given sufficient resources and time (one expert they interviewed suggested it might be completed within five years from now). It could become the ultimate lie detector test.

Of course, this raises all sorts of ethical issues. It would be invaluable in court, but as one expert points out, will it be considered physical evidence such as DNA or hair samples that police can get warrants to obtain from suspects, or will it fall under the 5th amendment, which provides that defendants in court cannot be forced to provide testimony against themselves.

Read the full-text at the 60 Minutes website.

Ice formations

Just before Christmas a neighbour from the other end of the lake discovered my blog while searching for photos of Kingsford Lake to send to a friend. It’s nice to know other people on the lake, but we haven’t met too many of our neighbours yet. Unlike in subdivisions, where you might meet someone who’s out shovelling their driveway while you’re walking your dog (or etc), you don’t tend to have many opportunities to run into your neighbours in rural settings. Most of the folks we’ve met have been deliberate introductions – for instance, Dan returning a dog to house 8994 (the number on the dog tag) and meeting the owners (it turns out their dog is a regular wanderer), or our neighbour to the south noticing me with Raven down at our dock, and coming down from his place to say hello. We have met a couple others on the road, but we still don’t know a lot of the residents. So it was nice to meet someone who’s been in the area a while and knows the lake and its people.

She sent me a note the other day to warn that the company who manages the dam at the north end of the lake, up near where their house is, had opened it up to allow some water to drain. She indicated that the water had been flowing through the dam at an impressive rate, which would cause the water level of the lake to drop abruptly and might make the ice unstable. We’ve heard some eerie groans and gurgles coming from the lake, often sounding remarkably like a bathtub draining, frequently at first though they’ve mostly subsided now. We’ve seen some of our other neighbours (whom we can identify from our house by their accompanying dogs) out skating or skiing on the lake the last few days, so this afternoon we decided to venture out with Raven for her daily walk.

When the water first started draining out of the lake from under the layer of ice, there would have been an air pocket between the new water surface level and the frozen ice above, sometimes referred to as a suspended ice roof. If this is large and/or the ice is thin, it can be dangerous, as the ice no longer has the pressure of the water pressing back on it from underneath and lending support. Even thick ice, that’s normally considered safe, has the potential to crack when it’s not supported by water underneath, and if someone falls through a hole into the water, their head and arms can often be below the level of the ice and therefore out of sight from potential rescuers. Some of the bathtub sounds we heard was likely air being sucked in from the edges of the lake or islands where the ice was open, to fill the void that the emptying water was leaving.

However, there is some evidence that the ice has settled as the water level dropped and now rests atop the water again. One of these signs is the ridges of ice affixed to the sides of rocks and tree trunks at the lake edges. I was really fascinated by the ledges left behind by the sinking ice, where it had affixed to the earthbound surfaces. You don’t think of the ice as moving, and yet here was evidence that it had.

I thought it was neat how you could see the progression of the sinking ice level. In some spots there where three or even four ice ledges, one above the other. If the gurgles were the air seeping in under the ice surface from the edges as the water level dropped, the groans must have been the ice itself settling back down to sit on the water.

The other apparent sign that the ice has settled down onto the water again was this. We found about eight of these holes. About 8 inches (20 cm) in diameter, and spaced regularly in a line across the open part of the lake, these were obviously someone’s ice fishing holes. The ice level in the hole was about an inch below the surface of the surrounding ice, and while most of the lake ice was cloudy white, the ice in the hole was a clear black. If you cleared the snow off its surface you could see the milky white of the thick lake ice forming the sides of the hole. The fact that the hole was frozen over implies that the ice was resting on the water surface, since if it had been drilled while there was air under the ice it wouldn’t have frozen closed again (there being no water in the hole to freeze). I suppose it’s entirely possible that these were made before the water level dropped; although they looked relatively fresh, it’s really rather hard to tell for certain. There was a layer of crusty snow over the pile of ice shards, which we got last night, so all I could really tell was that they weren’t drilled today.

The most definitive way to tell where the ice sits relative to the water, of course, would be to drill a small hole and check it directly. Our neighbour to the south has been checking the ice; when we saw him the other day he said that it was 6 inches thick, but gave no indication of whether there was an air pocket underneath. We don’t have an ice auger or a drill bit long enough to make even a little hole that we could poke a straw or stick through, so we have to rely on the information of others. As long as we haven’t had a warm spell to soften the ice, we’ve still been going out, but we stick to the shallows and go out in pairs and try to be careful while we’re out there.

Feeder bullies

You may think by the title of this post that I’m talking about Blue Jays, or perhaps squirrels, but that’s obviously not the subject of the photo above. No, the title refers to a couple of visitors we had to our feeders yesterday, a species we hadn’t seen around our house since the fall, and even then the ones we saw weren’t stopping to hang around. There were just two of them at the nyger feeders, chowing down with a large flock of American Goldfinches. Can you pick her out in the photo above?

Here’s a better look at the culprit, a little brown streaky bird that comfortably falls into the “little brown job” category. Pine Siskins are a type of finch that breeds in coniferous forests through most of Ontario, but more abundantly in the north (reflecting the relative abundance of their preferred habitat). They feed on the seeds of conifers, particularly White Spruce, White Cedar and Eastern Hemlock, and in years where these species produce low crops in the north the birds will irrupt south where they are frequently seen at feeders. They’ll often hang out at the nyger feeders with goldfinches, House and Purple finches, and redpolls, although depending on the number of perches you have in your feeder assortment usually the flocks don’t intermingle too much.

Superficially the siskins may resemble females of the different Finch species (that is, House, Purple and Cassin’s), but the siskins are noticably smaller than the other species, slimmer, and with needle-sharp bills compared to the thick, bulky finches’ bills. They usually show some sort of wingbar, and, most tellingly, they all sport yellow in the wings, although it can be fairly reduced in females (such as this one). You can just see the yellow edging to the wing feathers in this photo. If you’re outside listening to a flock, their basic chittering sounds like a standard finchy noise, but is periodically punctuated by a characteristic, long, buzzy, rising “Zreeeeee!”

Population levels are hard to monitor because of the tendency of individuals to wander in response to variable food availability – one year the big crops will be over here, the next they’ll be in this other spot, and so counts at any given spot will fluctuate greatly. This is true of both winter and summer populations, since there’s no point in raising a brood in an area where there’s no food. Pooling Christmas Bird Count results from Canada and the US since 1950 show no real long-term trend in populations. However, they do show huge variation in abundance from one year to the next, almost biennially. It’s an interesting graph; you can dial up more CBC results here.

Siskins don’t share the feeders well. This scene may look relatively peaceful, but it was one of just a handful of photos I got that looked like that. Most photos showed variations on this theme:

The siskins would throw out their wings and extend their heads to snap at the neighbouring goldfinches. Goldfinches squabble among themselves a fair bit, but usually aren’t all that forceful about it. They’ll stand up to each other, snap back and forth, before one finally gives in. They all respected the siskins, however.

Okay, okay! Don’t hurt me! The seed’s all yours!

Often departing rapidly. Check out the yellow in the wings.

Hey, shove over, punk! You’re in my personal space!

Your mama had chicken legs!

Finally. Room to eat in peace.

Hope springs eternal

Happy New Year to everyone! I hope folks are taking it easy and not too tired or hung-over from last night’s fun, if you participated. Any New Year’s resolutions among my readers? Mine is to try to be more organized and on top of things this year. Tied into that is a desire to break this terrible habit of procrastination that I have. Also a few other habit-related goals. Breaking habits are some of the worst sorts of resolutions because they can be so hard to follow through on and then continue with, but hope springs eternal, and at this time of year, the springs are probably at their highest.

I’ve only been to one or two New Year’s parties over the years, preferring instead to spend it quietly with loved ones at home, and so last night found Dan and I curled up on the couch, watching some programs on TV and generally having a relaxing evening. Today my parents came by for a holidays visit, which was also nice. It has been a couple months since they were last up, they haven’t been by since they bought their new home (the primary reason they were up this way so frequently before was because of the house search, and the length of the drive from their old home). We all went out together to take Raven for her daily walk (she was a bundle of excited energy over the arrival of visitors), and I took them down the road to my favourite property. I didn’t take any photos today, these are from a visit a few weeks back, when the snow cover wasn’t quite as deep.

Speaking of springs, I discovered this one on the property, just another reason I’m so taken with the place. I had followed the little creek back along its length upstream to find its source, since I knew the water didn’t cross the driveway anywhere, Sure enough, the stream seemed to emanate from the tangled roots of two large birch trees. I couldn’t see the water’s source itself, the hollows under the arching roots too dark to discern anything. The flow was strong enough that the source had to be more than just a seep in the rock bed.

There are three primary types of springs. The first, the one that most people have probably seen at some point, is a seep. Seeps are responsible for forming these sorts of icicle formations on the sides of rock walls or cliffs. They can be found occurring naturally, but just as often are the result of human activity, frequently the excavation of rock hummocks or ridges to allow the passage of roadways. More often than not when I pass a rock cliff along the highway during the winter it has at least a few icicle formations flowing from it. Seeps are the result of water flowing between rock layers, or through the gaps in porous rock, under the surface of the ground. When the water comes to a spot where the rock has been sheared away or otherwise exposed the water flows down along the rock face or pools on the ground, often creating a small creek.

The second results when the landscape is composed of rock, such as limestone, that is very susceptible to erosion, and over (a very long) time a network of holes and tunnels develop through the ground. Water flowing from one source may encounter a sinkhole, a spot where erosion has formed a tunnel through the ground, and the stream seems to disappear. The tunnel ends further along in the landscape, where the stream pops back to the surface and continues on. Such landscapes are called Karst landscapes, or Karst formations.

The third is the sort I suspect to be the case here, given that most of the rock in the area is granite, and is where water is actually forced by pressure upwards through a hole in the ground. If the pressure is constant, the water on the surface can’t flow back down through the hole, and ends up pooling around it. Some water will inevitably trickle back down through the soil, but if the pool basin is mostly rock, or if the rate of water being pushed out of the hole is greater than what can seep through the soil, the water will eventually overflow the basin’s edges and start off downhill, forming a small creek or stream.

What sort of pressure can cause groundwater to be forced upwards to the surface? There are two possible causes. The first is if the well goes down to an aquifer that is completely contained within bedrock walls. The pressure from the surrounding rock pressing in on the water will push it up through the hole, even though it’s against gravity. The other cause is a function of topography. In an area where the geology includes a layer of porous rock bookended above and below by dense, impermeable rock like granite or clay, a pool of water may collect in the porous layer if the ground level rises to each side. Water that trickled through the soil in the higher areas will flow through the porous layer and result in an aquifer in the depression in the middle. If it fills up enough such that the water level at the sides, where the porous rock layer curves upward, is higher than the ground surface in the middle, then there will be enough pressure from the surrounding water to push the stuff in the depression up through a hole or well that forms in the surface. This sort of spring is called an artesian spring (and the aquifer an artesian aquifer), named after the former province of Artois, France, where the first such wells were originally used.

Confused? Try imagining taking a colander and duct-taping up all but one hole at the bottom. Push it into a sink full of water, just so that the edges are still slightly above the surface, but the bottom of the bowl is well below the surface level. Water will quickly begin rushing up through the hole in the bottom of the colander because of the pressure being exerted from the water in the rest of the sink, even though it’s moving in a direction opposite to gravity. The duct-tape is probably not completely sealed, though, and I bet you see trickles coming out from the edges. These are like seeps, where the groundwater meets a hole in a vertical rock surface.

Springs can be classified by order of magnitude. The biggest springs, with the label 1st Magnitude, are ones that produce in excess of 100 cubic feet per second (2800 cubic litres per second) at their source. They decrease, as the system suggests, approximately by orders of magnitude (2nd is 10 to 100 ft3/s, for instance, and 3rd is 1 to 10 ft3/s), down to the 9th Magnitude, which is less than 1 pint/minute (8 mL/s). Without having an actual tool to measure the flow of water in the little creek, I would estimate it to be a 5th magnitude spring – one that produces water at a rate of about 10 to 100 gallons per minute (0.63 to 6.3 L/s). It moved along at a reasonable rate for its size, certainly at least a litre per second, probably more.

The water wound its way through the forest, the narrow stream bed bordered by hemlocks, Yellow Birch and other trees that enjoy moist soil, and emptied out into a small wetland that bordered the edge of the lake. I’ve found a few springs in our area, but this one is my favourite, both because of the mystery behind the origin of the water, hidden as it is beneath the roots of the birches, and because of the surroundings the little creek passes through and ends at.