Raven chases eagle

Posted on September 3, 2016 by Alistair

 

I know it happens, but I just don’t understand why a Bald Eagle would flee from a Common Raven. 

Once, when I watched a Red-tailed Hawk flee from the harassment of a raven, an experienced birder explained that ravens really do have sharp claws and from the point of view of the hawk, there is no point in risking an injury. Fair enough, the idea is: Just walk away (well, fly away) from a silly fight. But, surely the logic goes the other way around also: The raven would become lunch if the eagle actually chose to take it on.

A juvenile Bald Eagle just flew off when harassed by a Common Raven.

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Seasonal change

Posted on September 1, 2016 by Alistair

 

The season is changing. Of course, children are going back to school, but other species are shifting over to the winter residents. Steller’s Jays are back, as are cedar bugs (aka, stink bugs).

A sign of the shift for me is the arrival on August 30th of a Horned Grebe. They are usually present, except during the summer, when they breed farther north. 

The arrival of a Horned Grebe in the dying days of August was welcomed. However, this one has a rather odd extrusion of flight feathers erupting from its side. Can it fly? Well, it did arrive here.

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Win some …

Posted on August 31, 2016 by Alistair

 

The spawning season for kokanee brings out both predators and cameras. This combination increases the chances of capturing interesting scenes. Yesterday’s walk recorded winners and losers among the predators and some rather satisfying images.

A Common Merganser chasing a fish produces an impressive burst of speed — and a striking image.

Speed pays. Six seconds after being caught, the fish had vanished down the merganser’s gullet. 

While the merganser was a winner, this osprey lost. It did catch a kokanee now clasped in the bird’s left claws. Alas, catching a fish is only part of the exercise for it has to be lifted from the water and flown to a place where it can be eaten. This kokanee proved too heavy to lift. After three failed attempts, the osprey gave up and flew off without it.

Posted in birds, fish | 3 Comments

Hotspot

Posted on August 29, 2016 by Alistair

 

Now that the wildfire season seems behind us, no concern is likely to be raised by a discussion of something called the hotspot in the forest.

The hotspot is an optical phenomenon in the form of a diffuse bright region around the antisolar point. This is the point on the celestial sphere directly opposite the sun. It is also the location of the head of an observer’s shadow, if it can be seen. In the scene, below, the hotspot appears in the geometric centre of the picture. However, the hotspot is not fixed to the ground. It moves with the observer and the Sun.

The explanation of the phenomenon, also known as the dry heiligenschein, is remarkably simple. On an irregular surface, such as a forest, the view is of a mixture of the trees (or other objects) and their shadows. The exception to this blend of light and dark occurs at the antisolar point. Here one is looking directly down the sunbeam and here each tree covers up its own shadow leaving that spot brighter than elsewhere.

There is a hotspot in the forest in the centre of this picture of a tree-covered mountainside.

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Kingfisher’s fish

Posted on August 28, 2016 by Alistair

 

I am used to seeing kingfishers hunt from pilings. This one is a juvenile.

It seeks minnows and fry such as these shown a week ago

Having spotted something, the bird dives.

Carrying a minnow, it picks a piling upon which to feast. Unfortunately, the present occupant objects.

The kingfisher chooses a different piling and soon downs the minnow.

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Not a topiary

Posted on August 27, 2016 by Alistair

 

I had no idea what I was looking at, but it reminded me of an enormous topiary sculpted in the forest.

I was on an osprey survey with the Friends of Kootenay Lake. We were passing along the east shore of the Lake when a huge structure was spotted. Kat McGlynn said it looked like a mistletoe infection. 

This was subsequently confirmed and expanded when I sent the picture to Doug Thorburn, who said:

… this is a severe case of Douglas-fir dwarf mistletoe (Arceuthobium douglasii) … I am used to seeing it in the East Kootenay, and it is only recently that I realized how prevalent it is on the east shore of Kootenay Lake as well.

Douglas-fir dwarf mistletoe is a destructive native parasite that grows on Douglas-fir trees. In earlier times, frequent wildfires killed small infected trees, but with modern wildfire suppression, the parasite has spread. Similarly, logging, with its practice of harvesting the healthier trees and leaving the poorer ones has contributed to the spread of the parasite. (See, Douglas-fir Dwarf Mistletoe.)

I now fear its arrival on my side of the Lake.

The parasitic plant, Arceuthobium douglasii, has taken over a Douglas-fir and will kill it and spread.

Posted in commentary, wildflowers | 1 Comment

Mysterious bird

Posted on August 26, 2016 by Alistair

 

A blur flew past me over the calm waters at the mouth of Kokanee Creek. At first, it could have been almost any smallish bird: sandpiper, kingfisher, kingbird, any of a half-dozen local swallows. For five minutes it banked and swooped over the water apparently hunting insects. Although it remained a blur, its behaviour suggested a swallow.

I repeatedly tried to take its picture, but it flew too close and fast. Repeatedly, by the time I clicked, the bird had moved out of the picture. On the few occasions it appeared, it was badly out of focus — except for one clear shot. Yep, it was a swallow, and a juvenile, but which one?

It was a problem: Species identification seemed to change depending upon the portion of the bird being examined. I was out of my depth even though there were few choices. Eventually, the picture was shared among five experienced birders, and while acknowledging some inconsistencies, the conclusion was that the mysterious bird was a juvenile Cliff Swallow. Indeed, I know of a nesting site for Cliff Swallows only eight kilometres from this spot.

The mysterious bird scouring the air for insects is revealed to be a juvenile Cliff Swallow.

Posted in birds, commentary | 4 Comments

Rainbow season

Posted on August 24, 2016 by Alistair

 

One year differs from the next. Last year had a dramatic forest fire; this year almost nothing burned. Last year we hardly noticed black bears; this year they abound. Last year offered copious dragonflies; this year there were few.

There are years when one is treated to many rainbows, usually starting in June. This year, rainbows have been sparse. The one below, from last evening, is — sigh — offered as a bit of tokenism merely to acknowledge that the laws of physics still apply.

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Fish fete

Posted on August 23, 2016 by Alistair

 

When humans, bears and ospreys gather to watch the same thing, you know that the kokanee are spawning again. 

The objects of all the interest are spawning kokanee, the speckled, red and green, landlocked sockeye salmon that take over local creeks.

An osprey, which normally hunts over the Lake, now finds creeks of interest.

It soon flies off with lunch.

To the delight of those gathered to watch the spawning kokanee, a black bear worked its way up the channel travelling close to humans on the bank and under those on a footbridge. The bear had only one thing on its mind and offered hardly a sideways glance. Alas, when it did catch a kokanee, it was facing away, so there was no picture of that.

The bear dragged its prize up the bank and feasted.

It would seem that this bear’s mommy didn’t say it shouldn’t chew with its mouth open.

Posted in birds, fish, mammals | 3 Comments

Minnows and fry

Posted on August 21, 2016 by Alistair

 

These may be the most plentiful fish caught for sport in Kootenay Lake.

That is just a speculation as I am neither fisherman nor ichthyologist. Nevertheless, small children wading in the shallows catch copious quantities in buckets and fishermen collect them for bait. 

When a child, I called all of these tiny fish, minnows. Yet, many of these show signs of parr marks, which suggests that some of these are the fry of salmonoid species.

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