Exploring Kootenay Lake

Our three regular hummingbirds arrive in April to breed. First males come, soon followed by females. The three species are Rufous, Calliope, and Black-chinned. I have not seen a Calliope since early May (although others have) so I only show the other two.

Rufous males don’t stick around after breeding and begin their migration to western Mexico by early July. So the males are gone. The females stick around for only another few weeks, and are then followed by juveniles in August. It is now mid July and we are still being visited by Rufous females, one of which stopped by a few times this week.

The Black-chinned female is the most frequent visitor. She may be tending a nest, but seems more or less unconcerned by an adjacent human clicking a camera.

Occasionally, a male Black-chinned comes by. He is distinctly skittish. If the watching human so much as twitches, he is off.

The infrequency of the male’s visits made it difficult to obtain a shot of him flashing his purple gorget. Here is one attempt.

By watching eaglets over the last month or so, I discovered pin feathers. Mind you, I would have discovered them much earlier had I done more reading — or kept chickens.

A pin feather is just a feather during its formation. Normally, a feather is composed of non-living material, but when growing, it is enclosed in a protective keratin sheath and is supplied with nurturing blood. What is seen is the long whitish tube extending from a partially completed feather — a somewhat strange sight.

The problem with spotting pin feathers on a recently hatched chick is that the chick is usually deep inside the cup of a nest which is, itself, located high above eye level. By the time the chick emerges, the feathers have already formed.

However, I occasionally watched a nest of Bald Eagles from high on a distant bank, which placed my eye almost at the same height as the shallow nest. Further, the eaglets would occasionally spread their wings in practice flight, and in doing so, display some pin feathers on their wings.

I set the stage with a picture taken in mid-June (2021/06/14). I had used it earlier to illustrate that Bald Eaglets had mainly dark brown plumage, and so were readily confused with Golden Eagles. Most of the feathers shown here had already formed.

However, in a picture taken a week earlier (2021/06/06) white extensions can be seen from some flight feathers. At the time, I thought these were the feather shafts without realizing that they were actually enclosing keratin sheaths and were called pin feathers.

A picture of an eaglet’s spread wing in mid-June (2021/06/14) shows pin feathers on both the flight feathers and dramatically on the underwing coverts.

However, by mid-July (2021/07/11) all feathers look completely formed. Will flight be far off?

I include this picture of the two chicks, just because I like it (2021/06/29).

I then searched through my pictures of nestlings. The only one where I was looking down into the nest was one of robins. The pin feathers are apparent on the heads of the chicks (2016/07/14).

As wildlife contortionists go, few exceed the twists of the heron when it preens. It preens to repair its feathers and spread waterproofing oil on them.

The Great Blue Heron hunts for fish in Kootenay Lake year round. However, its numbers are greater in warm months. Further, its plumage evolves from juvenile to adult and from non-breeding to breeding season. The heron seen yesterday was an adult in its breeding plumage.

The white crown and black pigtail show this heron to be an adult. The orangish upper mandible and shaggy plumes on neck and back show it to be in its breeding plumage.

The heron seems to be acquiring oil from its preen gland on the base of its back. The oil is used to waterproof its feathers. The bird’s two shaggy plumes are clearly visible here.

The bill is used to preen most of its feathers.

However, the bill cannot be used to preen the feathers of the head, so a foot is employed.

Yesterday, a friend told me that she had just seen a Golden Eagle that was hunting by the lakeshore. I was assured that it must have been a golden as it was particularly large and brown. 

Hmm…, I was skeptical that a golden was what was seen. The problem is that a Golden Eagle didn’t quite fit the proffered description. Consider, a Golden Eagle: 

• prefers to hunt small mammals in the uplands, not fish at the lakeside
• a Golden Eagle is not particularly large, being slightly smaller than a Bald Eagle
• is brown, but so is a juvenile Bald Eagle, which does hunt over the lake
• can be distinguished from a bald by, among other things, it golden nape

Today, I visited the nest of a Bald Eagle, where its two (brown) chicks were holding court. When they fledge, they will appear larger than their parents for their feathers will not have been worn. However, they will lack the golden nape. 

Juvenile Bald Eagles are often misidentified as Golden Eagles, a result of being both brown and of wishful thinking.

Looking for an illustration, I visited a Bald Eagle’s nest and photographed two (brown) Bald Eagles chicks (and mommy) sitting on a nest.