Exploring Kootenay Lake

Birds that hide

Posted on November 6, 2011 by Alistair

In two days, I encountered two birds that hide. One apparently thought it was rather good at camouflage, but was actually comically bad. The other was superb.

The first bird was a Ruffed Grouse. I watched it as it watched me doing yard work. It seemed convinced it couldn’t be seen. Finally, I stopped work, fetched my camera, and took its picture. As I left, it continued to feign invisibility.

Then there is the snipe; I show pictures of two different ones seen at Kokanee Creek Park today. I spotted neither of them on my own—Derek Kite found them. He would say, there it is; I would say, I see nothing but grass.

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Beach frost

Posted on November 5, 2011 by Alistair

This is a good time of the year to admire the distribution of frost. When snow covers the ground, any frost on top of it is much more difficult to distinguish.

Frost formed when the surface temperature dropped below 0°C.

Frost forms when water vapour (in the atmosphere) diffuses toward a colder surface and condenses onto it as crystals. In that way it is just like dew, but frost occurs when the surface temperature is low enough for ice to form. Usually, the distribution of either frost or dew is locally uneven: some here, none there. This unevenness results from slight variations in the surface temperature: slightly below 0°C here, slightly above, there.

There are some common situations that result in these small variations in surface temperature: variations in soil (subsurface) conductivity; variations in exposure to sunlight; variations in exposure to the nighttime sky. For now, I will ignore the first two (maybe get some pictures showing them later), and just deal with relative exposure to the nighttime sky.

In this first picture, the frost on the grass avoids the trees, both under and beside them. It is not that the frost fell from the sky, as snow does, but that the tree is warmer than the sky. Everything emits (infrared) radiation: the ground does, the tree does, the sky does—and for that matter, a person does. The amount of radiation being emitted (that is energy being lost) depends upon the object’s temperature: the hotter an object, the greater its radiative output. So, imagine being a bug on the grass well away from those trees. You are both emitting radiation (losing energy), and you are receiving other radiation (gaining energy) from your surroundings—principally from the sky. The sky is much colder than you, so you receive less energy than you lose and your temperature drops below 0°C and frost forms. But, unlike the sky, the tree is roughly the same temperature as the ground. So near the tree, a bug will be receiving nearly as much radiative energy (from the tree) as it loses. The temperature does not drop as much and frost does not form.

The situation on the beach is similar even though the variations in terrain resulting from endless footprints are quite small. Here the frost hugs the ridges and avoids the valleys. Again, imagine being a bug on a ridge. The only radiation you receive to compensate for your own loss comes from the much colder sky, so your temperature drops. If you were a bug in the valleys, a portion of the sky would have been replaced in your view by valley walls—walls that are at about the same temperature as you are and a good deal warmer than the sky. On the ridges, there is a net radiative energy loss, the temperature drops and frost forms; in the valleys, the net radiative loss is smaller and the temperature does not drop low enough for frost. The valleys are just that little bit warmer than the ridges.

While both of the above pictures were taken this morning, I thought it would be fun to add a view of the same thing happening on a summer beach, but this time with dew. Again, the ridges are cold and dew forms; the valleys are warmer and it does not. Of course, another interesting comparison is the fact that the colder ridges, with frost, look lighter, while the colder ridges, with dew, look darker. That is a story for another time.

These are interesting things to watch for during early morning walks.

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Herons abound

Posted on November 4, 2011 by Alistair

I have experienced an upsurge in heron visits during the last couple of weeks. The same thing happened at this time a year ago. I wrote about it then in a posting entitled Herons return, and noted that now that the ospreys had left, the herons moved more freely about the region.

I see a heron every couple of days now. Indeed, yesterday, I saw five of them together—a somewhat unusual sight. Four had settled on some pilings and then a fifth flew past. Nice!

Usually these observations are made in the early morning light, a time when pictures of distant birds present technical problems. But, I attach one picture I did manage of a recent heron as it was flying. It serves as a token for all this activity.

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Grebe and sculpin

Posted on November 3, 2011 by Alistair

Our local sculpin is a small (6-8 cm long) secretive fish that spends most of the daylight hours well camouflaged and motionless on the floor of the Lake, often within rocky hideouts. By such devices, it tries to avoid predatory fish such as the trout. For one sculpin at the Nelson waterfront, this approach was insufficient to avoid a grebe.

Yesterday afternoon, I watched a Horned Grebe diving for fish in the water alongside the playing fields. I concentrated on the moment the grebe surfaced hoping it would display the result of a successful hunt. The grebe dived and surfaced many times before surfacing with a Slimy Sculpin in its bill. The sculpin fought and even escaped, but the grebe caught it again and down the gullet it went. Bye-bye sculpin.

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Last butterfly

Posted on November 2, 2011 by Alistair

Proclaiming the observation of any species as being the last of the season is fraught with problems—you just might see another a few days later. Yet, a butterfly on November 1^st has to be close to the last.

Posting updated on November 4th: The butterfly, below, has now been identified by Jon Shepard, an author of, Butterflies of British Columbia, Guppy & Shepard (2001). He wrote me to say:

The anglewing is Zephyr or Polygonia zephyrus. The submarginal row of light spots on the upper side of the hind wing are larger and more diffuse than for either P. satyrus or P. faunus.

It is certainly a good, late record!

Indeed, according to his book the latest observation for this species in BC is the second week in October—and that was probably at the Coast. Yet, this Zephyr Anglewing (its common name) was observed flitting about a marshy region of Kokanee Creek Park in the first week of November.

It was a pleasant if unexpected sight.

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October odonata

Posted on October 31, 2011 by Alistair

One might have thought that with dropping temperatures and turning leaves, dragonflies and damselflies (insects of the order Odonata) would have vanished. Yet, while October is their last stand of the year, some remain. Admittedly, they seem to spend a great deal of time seeking sunny spots.

Below are a handful of Odonata seen in the last week and a half.

The Pale Snaketail is seen around the shore of Kootenay Lake frequently during the summer and early fall where it is often seen hunting from a resting place on a low surface. The female lacks an ovipositor and is seen here apparently resting between dropping her eggs (yellow mass at the tip of the abdomen).

Most of the dragonflies I see at this time of year are meadowhawks. These are much smaller than the snaketail and the males are generally coloured in red and black. One exception is the Black Meadowhawk, which shows no red. The male is shown first.

This is a female Black Meadowhawk. She starts the season in much lighter shades, but by now is quite dark.

During the summer, the only damselfly I see around the Lake is the Tule Bluet. But, here are two Spotted Spreadwings, the female first, the male second. Typically, this is the last spreadwing to fly in the fall.

I suspect that these are the last Odonata I will see until late spring of next year.

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Procter to Nelson

Posted on October 29, 2011 by Alistair

When I was a child, the CPR ran a passenger service between Procter and Nelson (and beyond). From early in the century until 1953, the train was pulled by steam engines—thereafter diesel. Although I watched both frequently, I only rode this portion of the line once. On that occasion, in the summer of 1957, I was the only passenger on the train—no wonder the service was doomed. The following year, the CPR switched to Budd cars (diesel engine and passengers in a single car) and in 1964 dropped passenger service entirely.

Since 2009, the Kootenay Rail Service Society has been working to reestablish passenger rail service between Procter and Nelson. Greg Nesteroff has written stories about this for the Nelson Star. One was illustrated with a picture of the old Procter Station; a second with a picture of an impressive mainline steam engine that seems to have passed along our local line exactly once, and that in 1937.

Of course, if service were reestablished, a steam engine would not be used; to do so would be far too inefficient and polluting. Yet, since the latest story in the Nelson Star had used a picture of a steam engine that was distinctly uncharacteristic of the line, I thought it would be fun to show the typical engine.

Below is not only the engine of my memory, but it was a longtime standard on the line both for passenger and freight use. I was standing beside my cousin, Denis Daly, in 1949 when he took this picture at Troup (located between Procter and Nelson).

Posted in history | 3 Comments

Elephant lines

Posted on October 27, 2011 by Alistair

I have long been struck by the patterns of vegetation on Elephant Mountain (officially known as Mt. Nelson) across the water from the city of Nelson. Why is there this odd pattern of coniferous and deciduous trees? It is particularly visible in the fall when the deciduous trees turn colour, but also apparent in the winter when they have dropped their leaves.

Is this pattern random? Does it reveal some underlying structure?

One way to assess the issue is to look at the mountain from various perspectives and see if a regular pattern emerges. The instrument of choice is Google Earth. The second picture shows such an autumnal view captured in April of 2008. (The present Google view uses an image from a different time of the year and the pattern is not as evident.)

The Google image shows that there is a simple pattern to the deciduous trees on Elephant Mountain and in Grohman valley to the left: the orange lines are nearly parallel to one another and cut across other features of the terrain such as creeks. This implies that the pattern reflects an underlying geological structure. What it is, is as yet unclear.

The lines of deciduous trees on Elephant Mountain, as seen from the bridge, look somewhat chaotic.

When seen from the east in Google Earth (2008), many of the lines of deciduous trees seem to be parallel and unrelated to the pattern of drainage. This suggests an origin that lies in the geological structure.

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Why take pictures?

Posted on October 26, 2011 by Alistair

I confine myself to local nature photography.

As I look around the websites of nature photographers, I detect a pattern: purchase my picture. Now, I am not suggesting that this is the only, or even primary, reason the pictures were taken. But, this seems to be a major reason that nature pictures are posted on personal sites: look at my work and buy. Well fine, and why not?

Yet, that is not the reason—the monetization of my delights—that I take pictures. I take pictures so as to better understand my surroundings. Consider the following (which will make no sense at all to those who view everything as a commodity to be sold).

Last Sunday, I went for a walk in a marsh. During that time I observed (what I then believed were) sparrows. Certainly, they looked like sparrows. The only challenge I faced was to decide just which of the various types of sparrows they were out of the dozen or so possibilities.

Yet, I took pictures and it was those pictures that chastened my assessment—not the original observation—it was the uncompromising pictures. After about five hours of on-again, off-again checking, I learned that these were not sparrows at all, but a lookalike: a female Red-winged Blackbird.

The pictures were grounded in a reality that my more casual observations failed to achieve.

Some female Red-winged Blackbirds visit the marshlands of Kokanee Creek Park.

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Two waders

Posted on October 24, 2011 by Alistair

Yesterday, I watched two very different wading birds: a heron and a snipe.

The heron flew overhead and I managed a picture.

The snipe flushed only a metre from my feet and vanished before I could even point the camera. Fortunately, Derek Kite took some pictures of the same snipe a couple of days earlier and has allowed me to show his.

A Great Blue Heron flies overhead

Two of Derek Kite’s pictures of a Wilson’s Snipe