Exploring Kootenay Lake

We get three species of hummingbirds around the Lake: Calliope, Rufous, and Black-chinned. Well, really occasionally, the Anna’s has been seen, but not by me.

Some years I have seen only one of the species, sometimes two, and now and then there will be a summer when I see all three. Amazingly, in an hour this morning, I saw all three species. The morning offered a humdinger of hummingbirds.

The Rufous Hummingbird is the scrappiest and most likely to be seen.

The Calliope Hummingbird is the smallest and next most common.

The Black-chinned Hummingbird is the least likely to be seen.

Most mating between Mallards seems to be consensual and initiated by the female. Yet, there are more males than females. This leads to roving bands of bachelor drakes. This, in turn, leads to rape — or as naturalists delicately put it: forced copulation.

Ducks are not humans and the forced copulation presumably has evolutionary advantages for the species. Yet when seen through human eyes, the behaviour is disconcerting. 

Mommy Mallard was taking her dozen ducklings out on the water. Being a member of a sexually dimorphic species, the mallard female attends her chicks without male support.

So it was unexpected to see two males swimming towards the family. There, they began neck pumping, a sign of courtship. Mommy quacked her objection to this inappropriate behaviour.

Mommy’s first thought was to escape. However, she has a problem: if she leaves, her chicks are vulnerable. So, she returned.

Having returned to guard her chicks, Mommy was put upon. 

As far I could tell, over the next few minutes the males took turns.

“Oh come now; Do you have to do this in front of my chicks?

“What are you doing to Mommy?”

I really like the tranquility evinced by this picture of a Mountain Bluebird. But I didn’t initially bother to share it in a posting.

Didn’t bother, that is, until I abruptly needed it as an antidote to what I witnessed today at noon (next posting). So, enjoy the serenity while you can.

Common Loons spend the winter along the Pacific Coast. In spring they arrive at interior lakes to breed. Upon arrival they are at once friendly to partners, and highly aggressive to rivals.

The problem loons seem to have is: Which is which? To human eyes, both sexes look alike, and if last week’s observations are a guide, the loons, themselves, often seem unsure of who’s who.

This is a tale of three or four Common Loons coursing about on one of the lakelets of the West Arm of Kootenay Lake.

These two Common Loons had been swimming together for a while, and one occasionally displayed for the other. They seemed to be friends.

Farther out on the water, a lone loon had been swimming when another spotted it and landed nearby. They approached gingerly, apparently unsure of the identity of the other.

Abruptly the decision was made: foe. How each determined this was unclear to me.

Each backed away and reared up aggressively.

Each thought it could win, so the fight for supremacy began.

And continued.

One loon was losing and broke away.

The victor would not leave well enough alone and chased the loser back and forth across the water for another five minutes or so. Each bird planed. There was a great deal of energy put into the exercise before the vanquished loon ended it by flying off.

Elsewhere on the lakelet, these two were seen. I rather suspect that they were friends.

A year ago in planing waterbirds, I wrote about an uncommon behaviour of some swimmers.

When swimming across a water surface, water birds usually float. Called displacement mode, a bird is primarily supported by its buoyancy (static pressure). However, its swimming speed is constrained by the waves it makes to what is known as the hull speed (see, muskrat hull speed). To swim faster, a bird can either dive, or switch to planing mode.

In planing mode, a bird is primarily supported by the lift provided by the rush of water against its slightly tipped-up body (dynamic pressure). The problem is that for a bird (or boat) to plane requires not only much greater power, but also the right body (hull) shape. These things were explored in the essay.

While I knew that a Common Loon could plane, I hadn’t managed a picture of it until this last week. Present were all the characteristics (which are shared by planing boats):

• It travelled at a much greater speed than possible in displacement mode.
• The bird’s breast was lifted slightly allowing water to rush against a tipped-up body.
• The tail was pressed downward to mimic a boat’s sharp transition between hull and transom.
• The wake took the form of a rooster tail. 

Other aspects of loon behaviour seen on this occasion will be explored in the next posting.

A Common Loon planes across the Lake.

A year ago (Tomfoolery), I watched as a female Wild Turkey was viewed with appreciation by two males. However, the two males were so obsessed by a concern for their rival’s attentions, that neither could attend to the female. It was odd; neither mated with her because each wished to block the other.

This situation seems to have been repeated with Red-winged Blackbirds.

This fetching female Red-winged Blackbird was hanging out in the vicinity of a couple of males.

Here are the two male Red-winged Blackbirds.

One male spent its time denouncing the other.

It then flew after the (imagined) interloper. But, the conflict meant that neither male mated. Odd.