White line

 

Some interesting lake features are most easily seen during the low water of April. Such is the case for the white line that runs around the rocky portions of the lakeshore. I last discussed the white line seven years ago in 2012. The present low water seems to be a good time to mention it again. 

For the longest time I wondered whether the rocks were white because the lake had washed them clean, or whether the lake had deposited something on them. The answer is deposit. The deposit is calcium carbonate (CaCO3), a common substance found in rocks in all parts of the world. It is the main component of shells of marine organisms, snails, coal balls, pearls, and eggshells. 

CaCO3 is poorly soluble in water, but it is soluble. It is carried into the Lake from the rocks in the surrounding mountains by the creeks. But, the amount in the lake water seems to be fairly small —  our lake water is sub-saturated in CaCO3. So, why is it even noticeable along the shoreline? There seem to be two answers: waves and declining water levels. 

Waves splash onto the rocks wetting them. The water then evaporates, but the CaCO3 remains and piles up leaving a white deposit. Similarly, when the lake level drops, the rocks that were previously underwater are now exposed. The rocks dry and a deposit of calcium carbonate is left on them. 

When the lake rises again, the white line is again under water where the calcium carbonate is slowly dissolved leaving the rocks clean and the cycle is repeated.

There are two white lines on these rocks. The upper one is probably the result of waves splashing onto the rocks when the lake was higher. The lower broad one is probably the result of the recent drop in the lake level.

A close examination of these white lines shows a fair bit of fine structure that mirrors not only changing lake levels, but passing storms.

Posted in scenes, weather | 1 Comment

1,500th posting

 

This is the fifteen-hundredth posting to the blog, Exploring Kootenay Lake. The oldest was a decade ago in December, 2009. The blog is merely a notebook to which I regularly record delight with my surroundings. Yet, as these notes are on the web, they are viewable by others.

I did not even notice when I reached 500 postings, and I similarly breezed past the thousandth posting without a thought. However, about a month ago, I did notice that I was approaching 1,500 and decided to take it as an opportunity for reflection.

Viewers will have noticed that postings are primarily concerned with looking outwards towards nature, rather than inwards towards humans. This is purposeful. Websites about human activities abound. (Even conservationist sites seem designed more to persuade than enlighten.) Who needs yet another human-centric site?

Besides, the manipulation of others is not my thing.

I wander woods and waterways taking pictures of nature. However, I do not post my images to picture-sharing sites, for such sites strike me as having been designed to emphasize clicking over thinking. Rather, I post to my own blog where I use one or more images to tell a story about the behaviour of the natural world.

That is my thing.


(Below are many images.)

From the pre-blog website

In this retrospective, I start by showing four images from the blog’s precursor, a website launched in 2005 for the simple reason that when I sought regional insights, I found no comprehensive source, so set about providing them myself.

Each year, at summer’s end, Kokanee gather in local creeks to spawn. The fish then die and provide a feast for others.

I delight in patterns seen in snow and frost. This one is uncommon. Most frost is formed on a surface when water vapour is cooled. Not so for these frost flowers. They grow just above the surface by the same process that produces steam fog: the mixing of water vapour with different temperatures. I find the resulting frost flowers to be beautiful.

The region around the Lake used to have many fruit ranches. The fruit trees are long abandoned and it is likely that only the wildlife now know their locations. Here a white-tailed buck eats an apple from one of the remaining trees.

For the longest time, this matutinal shot of migrating Trumpeter Swans resting in the shallows on the east side of Kokanee Creek Park was my favourite image.

 


From the blog

Below are a handful of images drawn from the five or six thousand pictures posted to the blog over this last decade. My present choices are somewhat arbitrary in that there are probably a few hundred more that would count as decadal favourites. As I look over the ones selected for today’s retrospective, I notice my neglect of many interesting posted topics: arthropods, wildflowers, clouds, lake processes, snow, frost, and dozens of mammals and birds. Below, I seem to have favoured scenes featuring either action or interaction. 

2009
A steam devil moved along Kootenay Lake on a brisk and frigid December morning. Analogous to a dust devil, the steam devil originates when a vortex in the wind sucks up the steam fog spread over the Lake’s surface. I have photographed these devils a few times in the last decade, but this shot remains perhaps my favourite.

2010
White-tailed deer are a common sight at the valley bottoms. They are frequently seen browsing in yards and alongside roads. However, not only are doe and buck seldom seen together, but rarely are they seen charging headlong towards the camera. These two had been spooked by a dog and did not realize that I was watching along their path of retreat.

2011
The kestrel is our smallest resident falcon. It nests in tree cavities, but, as it cannot carve them itself, will use cracks in the trunk, or flicker cavities. There were two chicks in this cavity, one of which is urgently anticipating breakfast in the form of a headless bird served by father. The breakfast bird is headless because the male kestrel stopped on the way to the nest and ate its tasty brains. There is just no point in wasting the really good stuff on the kiddies.

2012
Sightings of Ogopogo, a tremendously long, serpentine lake monster, have been reported on Kootenay Lake for 120 years. This was the first of two times I had seen it. Ogopogo undulated its way along the West Arm heading towards Kokanee Creek Park. When it spotted me watching from the shore, it abruptly turned and headed straight towards me. Wow, an opportunity to get close shots of our favourite aquatic cryptid. As Ogopogo neared, it resolved into a family of otters travelling in single file. What amazingly good fun. It is no wonder that Ogopogo has been reported in many of BC’s lakes, not just in those of the credulous Okanagan, where in 1989 a mayor persuaded the government to issue a protection order for it under the BC Wildlife Act.

Actually a large vole, the muskrat is our most frequently seen semi-aquatic mammal. In the early spring, it leaves its characteristic waterways and wanders afar looking for a mate. Although seemingly looking right at me, I was probably unobserved: it has rather poor eyesight.

2013
The Great Blue Heron will eat anything it can catch and swallow whole. Here, it has stalked and, with a quick thrust, captured a vole. What is so striking about this image is the eye-to-eye contact between predator and prey. Does the vole realize that in a moment, it will be looking at the dark inside of the heron’s gullet?

I am a fan of meteorological optics: patterns of light in the atmosphere such as rainbows, haloes, coronas, sky colours, and mirages. This wave cloud is iridescent. The colours arise from constructive and destructive interference of sunlight as it passes around uniformly sized droplets.

2014
I encountered this Bald Eagle as it was using its hooked bill to tear apart and eat a rather large rainbow trout. I rather liked its dynamic stance.

This rainbow picture was over thirty years in the conception. That is how long I had sought a low-sun, semi-circular, rainbow with the circle completed by a reflection in calm waters. Alas, stormy waters are usually too rough for a good reflection, and one is rarely in the proper position to see it. On this June evening, everything came together along the West Arm of Kootenay Lake.

2015
This all-time favourite shot was not taken by me, but by my grandson, Finn (then, aged 11). It shows a grizzly sow with her three cubs. She has taken them into the brush to avoid the attention of the grizzly boar, whom she is watching. She is attempting to protect her cubs from the threat posed by what is likely their own father. As the sow will not mate with him when she has cubs, his simple solution is to kill the cubs. 

A delight of summer are Tree Swallows. During acrobatic flight over the water, they capture endless insects that are then fed to ravenous chicks. We cannot see what this father is bringing them, but his chicks’ enthusiastic anticipation is evident.

2016
A black grizzly sow stood up and challenged me (black is a known, but uncommon shade for grizzlies). She had taken umbrage at my watching her cubs. If anyone is wondering, I do not recommend having such a close encounter with a black grizzly — she was ticked. 

2017
The Merlin, the other one of our resident falcons, weighs only about 0.2 kilograms, but is amazingly feisty. Here it has attacked, killed, and is now eating a male Mallard, a duck that outweighs it by a factor of six. It even looks willing to take me down if I approach closer.

A black bear cub has just caught its first Kokanee. For weeks prior, mommy had caught the fish, taken them to the bank, and torn them into pieces for her cubs to eat. Now it was the cub’s turn to catch one — although he didn’t seem quite sure what to do with it.

As birds lack teeth, the size of the food most can eat is limited by their ability to swallow it whole (an exception is raptors which use a hooked bill to tear a large item apart). This male Hooded Merganser has caught a sucker. It aligned the fish with its bill, then tipped its head back and swallowed it whole.

2018
Surely no fecund female Wood Duck could possibly resist this lad in his mating garb.

The Osprey feeds exclusively on fish that it catches live when it plunges up to a metre deep into the Lake. It then struggles to lift the fish from the water and fly off with its prize. Each participant is symbolic of the Lake — think Kokanee Creek and Osprey Ferry. So recording their interaction was a delight. But, just try to capture such a transient event somewhere out over the open waters of a large lake. 

2019
Many finches are so attracted to salt that they flock to winter highways where they feed amidst the traffic. Ravens monitor the inevitable carnage from trees, and after a vehicle passes, fly down and pick up the dead or injured. Here, a Common Raven flies off with a male Cassin’s Finch.

Now to merely carry on exploring local nature — all the while trying to avoid the front end of black grizzlies and the back end of striped skunks.

 


Posted in birds, commentary, fish, mammals, weather | 23 Comments

Guttation of spring

 

A sure sign of new springtime growth is guttation.

The water drops on the grass in the morning might have been casually dismissed as being dew. Not so, they are guttation. OK, there was also some dew on the grass, but what caught the eye were the large drops of guttation. The significant thing is that dew can form on any solid object; Guttation can only form on vegetation that has been transpiring. 

Dew
When water vapour (mixed in the air) is cooled by contact with a cold surface, it condenses as liquid droplets on the surface. While that surface could be living (such as a leaf), it could just as easily be a rock or sand on a beach. In the picture below, the dew is the tiny droplets that lie along the blades of grass, not the large drops at the tips of the blades.

Guttation
Guttation (from Latin, gutta, meaning drop) is water that has been pumped up from moist soil and through the plant, rather than water that has been deposited directly from the atmosphere onto the leaf, as dew has. When roots are warm and moist, they pump moisture and nutrients to the rest of the plant. That moisture is then transpired through the stomata on the leaves. However, during the low temperatures of night, the stomata close. When the stomata are closed for the night, do the roots know that there is now no point in continuing to pump? No, they don’t. Grass is not very smart: if roots are still warm and moist, they pump. The result is that the moisture is extruded from the tip of the blade where it forms a large drop. This is the guttation. Clearly, the appearance of guttation indicates a non-dormant plant — one that is growing.

Large drops of guttation on the tips of these grass blades indicates that the grass is now growing — it is springtime. 

Countdown: 1

 

Posted in weather, wildflowers | 7 Comments

Three mammals

 

One does not often see wild mammals during the winter — that is, leaving aside the two staples: red squirrels and white-tailed deer. Each of these were photographed during the recent week in my yard.

The third mammal, a yellow-bellied marmot seen elsewhere, was more interesting.

A red squirrel visits my home.

A fawn and doe look up while resting in my yard. Their eyesight is not particularly good, so by my remaining motionless, they were not really sure that I was there. 

Marmots hibernate though the winter months. Previously, my first observations of yellow-bellied marmots have often been in mid March, and sometimes in late February. The first observation this year, however, took place early in April. 

Countdown: 2

 

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Eagles don’t cooperate

 

At sunrise this morning, four eagles (three adults, one juvenile) harassed one another over a catch. Consequently, none of them made the kill and the prize escaped.

It all started when one adult flew low over what was probably a duck. The eagle’s legs were lowered and its claws were extended in preparation for a dive onto the prize when another adult, wanting it for itself, interfered. Then a third adult and juvenile joined the harassment. 

OK, Bald Eagles don’t flock, but this sort of behaviour — if I cannot have it, no one can — proved rather unproductive. However, the duck probably thought that it all worked out rather well.

This is one of the adult eagles flying back and forth preventing others from making a kill.

And here is the juvenile also contesting the prize.

Countdown: 3

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Lake ullage

 

Kootenay Lake is at the lowest level I have seen it in the last couple of decades. The low water of March and April is, of course, an annual spring feature, which occurs when there is a reduced inflow because mountain moisture is still locked up as snow. This will reverse during the spring freshet of May and June when those snows melt and cause the Lake to rise to flood levels.

Yet, sometimes the learning of a new word changes the focus of one’s perspective. That word is ullage: the amount by which a container is NOT filled. This is a term used in the beverage industry — although it is more broadly applicable — to indicate the unfilled headspace in a container. 

By the ullage measure, if the typical summer lake level is 531.3 metres above sea level, and the present level is 529.9 metres, then the ullage level might be said to be about 1.4 metres. Of course, if one judged what is full by the highest water level and chose the 2012 level at 534.5 metres, the present ullage would be over triple that at about 4.6 metres. 

Curiously, this rather high ullage is the reason that loons don’t nest on this lake. Certainly they visit, but since they build their nests along the shoreline, the high ullage range of this lake gives them problems. So, they nest on smaller mountain lakes which have a much smaller ullage.

An illustration of the present rather high ullage is the Kokanee Creek boat launch. Consider the unlikelihood of being able to launch a boat from it today.

Countdown: 4

 

Posted in birds, commentary, weather | 1 Comment

Magpie packing

 

The Black-billed Magpie is a fairly common bird of western North America. However, as it prefers open habitats with only clumps of trees, it is somewhat of a rarity in our heavily forested region. As a result, it is a delight to encounter.

A magpie flew past carrying a lumpy something in its bill — but what is it? The magpie is an omnivore, so it is just unclear whether its prize is animal or vegetable. 

While the magpie’s comestible is indeterminate, one feature is obvious from this side view: the magpie’s unusual tail makes up more than half its body length.

Countdown: 5

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Flying with fish

 

This morning, a Bald Eagle flew past packing a fish athwart its body. It is odd that an eagle regularly carries a fish in this non-aerodynamic orientation. Granted, the eagle is a strong flier, so the extra drag of a fish being carried across the airstream may not matter much to it. Still, why does it go to all that extra work?

An Osprey always carries a fish aerodynamically with its head facing forward. Granted, an osprey is a smaller bird, and as it takes less effort to fly with the fish in this orientation, the bird does so.

But, how is it that the eagle has never learned this trick?

An eagle carries a sucker in a non-aerodynamic orientation, so has to work harder to fly with it.

Ospreys have yet to arrive this year, so here is a picture taken last August. The osprey flies with its fish in an aerodynamic orientation and so does less work when flying with it.

Countdown: 6

 

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Muskrat of spring

 

Early in the spring, young muskrats start wandering in search of mates and new nesting sites. So, for the next couple of months, muskrats may be seen straying beyond their characteristic waterways.

The muskrat sometimes gets a bad rap: It is not a rat, but a large aquatic vole. Besides, it is primarily a vegetarian. 

It is spring and a young muskrat’s fancy turns to searching for a mate.

Countdown: 7

 

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Geese, synchronized flapping

 

The synchronized wing flapping of a Canada-Goose couple was spectacular. I assume that theirs was a pre-copulatory, courting behaviour, but I did not see them complete the act.

The geese, one in front of the other, rose out of the water and together spread their wings back.

Together, they swung their wings to the side.

And then to the front. 

Countdown: 8

 

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