Foam Lake Birding No. 132

FOAM LAKE BIRDING


No. 132

With this first snowfall I thought it might be appropriate to write about something that is more closely associated with snow. This idea led me to thinking about owls even though many owls do not like snow too much and migrate to warmer places. These mostly nocturnal birds have been mentioned in literary works for many centuries and in many cultures with the most recent example at the beginning of the first book of the Harry Potter series. Why? Owls have several characteristics that captures man's attention and imagination with the most important one being its ability to function at night, something man cannot do without technological help. When one throws in the owl's ability to fly absolutely silently and its unique hooting call into the mix, humans give the owl a kind of uncomfortable and grudging respect. Finally, owls are the only birds that have their eyes placed directly in front providing them with binocular vision making them more effective hunters. This placement of the eyes closely resembles that of humans thus the owl has acquired the reputation of being wise even though it is not too bright as far a as birds go. For a more detailed discussion of the unique characteristics of the owls refer to Article No. 35.

There are ten, yes ten, species of owls that can be seen in our area at one time or another depending on the time of the year and the kind of year it has been weather-wise. Of the ten species, two are year round residents; five are summer residents that migrate south for the winter; three are permanent northern residents that periodically show up (irrupt) out of their normal range in the winter. Of the last three, only the snowy owl is commonly irruptive and can be expected in our area every two or three years or so. The other two can be expected only once or twice every several decades.

Because I have no photos of any "winter" owls I chose to write about a common, but seldom seen, nocturnal little owl, the Northern Saw Whet Owl. It is one of the smallest of owls and definitely the smallest one that we will encounter in Saskatchewan. How small? A robin is about 10 inches in length; the Saw Whet is only 8 inches long but with a shorter tail. Try and imagine a big headed brown robin streaked with white. Because of their small size, nocturnal habits and migratory nature Saw Whet Owls are seldom seen by man.

Early European settlers gave the owl its name after the sounds it makes which is a raspy toot repeated about twice a second and reminded them of the sound made when sharpening (whetting) a saw. I have sharpened saw blades but have never heard a Saw Whet owl call so I cannot comment on the matter.

The first time, and for many years the only time, that I saw a Saw Whet was an encounter with a flock of six one summer when I was about 12 years old. The owls were perched in trees near one of our sheds and just kept sleeping soundly completely oblivious to our stealthy approach so as to get a really good up-close look at them. There was no need for caution as the owls were very tame allowing us to come right up to them, pick them up from the trees and then carry them around. My two younger brothers and I "played" with them the whole day being very careful not to hurt them in any way. Strangely enough the owls did not seem to mind the experience at all. One time one of the owls that was sitting on my finger managed to clamp down rather hard and stick one of its claws into my skin. I instinctively jerked my hand back owl and all. That was not a wise move as the little owl then really clamped down on my finger, as if holding on to struggling prey, causing me some real pain. Realizing what had happened I forced myself to relax and the owl let go of my finger. We were hoping to see them the following day but they flew away during the night putting an end to that little episode. They certainly were cute.

For many years I thought the six were a family group of two adults and four young but that was not the case as all six were medium brown in colour streaked with white which indicates adult birds. Juvenile birds are a dark chocolate brown that are so completely different from the adults that for many years they were thought to be a separate species, the Kirtland's Owl. Furthermore owls rarely, if ever, rear four young with two being the norm.

This week's photo was taken in a desert park near Tucson, AZ. The Saw Whet is a permanent resident in northern Arizona but is a rarity where it was seen. Needless to say it caused quite a stir among local birders.

Foam Lake Birding No. 102

FOAM LAKE BIRDING
No. 102
Now that the snow is here to stay it is time to cover a bird that is common here in winter. Since winter birds have not yet arrived from the north one is left only with permanent residents. To me, permanent residents are sort of special because they provide some measure of stability in the environment when everything else is changing with the seasons.
One of our permanent residents that is seen more often in the winter than in the summer is the Great Horned Owl, so named because of the feathered tufts on its head that look like ears or horns. Being nocturnal for one thing and being busy rearing young for another creates the impression that the owls are absent in the summer. They are not. In rural areas they can most often be heard and seen around dusk especially on warmer winter days. Their low pitched but powerful hooting can be heard a long distance away.
The only other owl that it can be confused with is the crow sized Long Eared Owl (see Art. No. 35). The easiest way to tell them apart is by the pattern of the brown and white markings on the breast and belly. The Long Eared has brown streaks (stripes) that run the full length of its breast and belly; the Great Horned has the brown streaks (bars) run across the breast and belly. In other words, the Long Eared is striped; the Great Horned is barred. Locally, only the Great Horned is present in the winter.
The chicken sized Great Horned Owl is one of our largest and most powerful owls being able to take prey animals the size of skunks which they often do. (It is a good thing owls do not have a sense of smell). More than once, as a youngster on the farm, I would be in bed for the night with the windows open and hear one of our cats yowl in terror followed by silence. Even though nobody actually witnessed the event, everybody knew that one of our cats had become owl dinner. In one sense it was a bit sad but on the other hand it did keep the cat population in check. Anyway, nature is what nature is and that is about all there is to it.
Locally, Great Horned Owls start to nest as early as March utilizing previous years' crows' nests. This early start gives the young a chance to mature and learn how to become good hunters over the summer time when prey is young, not too wise and plentiful. Even so many juveniles actually starve in the winter. There have been reports of owls actually falling out of trees, dead, from lack of food. Winter is an especially difficult time for all predators.
This week's photos were taken in a rocky area of the Saguaro National Park on the outskirts of Tucson, AZ. Incidentally, this is the place where my wife's sharp eyes prevented my stepping on a four to five foot Diamond Back Rattlesnake that was stretched out on the path directly in front of me. We waited patiently as it slowly moved off. Anyway, the excellently camouflaged female owl was sitting on her nest on a ledge on a cliff while the male was sitting guard a short distance away. Males and females are the same. The birding groups we were with took great pains not to disturb the nesting owls. Our guide told us that it was to prevent the owls from abandoning their nest. I was not so sure. Great Horned Owls have been known to attack human intruders viciously leaving some severe damage around a person's head and neck. Whatever the reason it is best to keep a nesting Great Horned Owl and people apart.

John Senkiw

Foam Lake Birding No. 35

FOAM LAKE BIRDING
No. 35
It is time to write about another one of our residents, a bird that is only somewhat migratory, and at the same time, introduce the readers to a new group of birds – the owls. Most owls, but not all, are nocturnal. That is, they are active only at night. Because owls do not have sonar capabilities (the way bats do), they, as a group, have developed a number of characteristics that make them special, as it were.
First, an owl’s feathers have special barbs on them that allow the bird to fly in complete silence. In other words, there is no “flapping” or “whooshing” sound as the bird flies through the air. This feature allows the owl to fly right up to its prey without the prey ever hearing it. This characteristic is unique to owls and of tremendous advantage to them.
Second, their eyes have several adaptations that allow them to see in very poor light (no owl can see in total darkness). The eyes are disproportionately large in relation to an owl’s body size. Most birds (and man) have two kinds of cells in their eyes – rod cells to pick up light, and cone cells to pick out colour. Because much of the eye is occupied by cone cells, these creatures see colour, but have poor vision in dim light. There simply are not enough rod cells! They are always diurnal (active only during the day). To overcome this problem, owls have evolved with rod cells only. They do not see colour, instead they have excellent vision in dim light because of the very large eyes that are full of rod cells only. This is a great advantage for a predator.
Third, in order to physically allow an owl to have such disproportionately large eyes, there are no eye muscles to move the eye around the way man does. This lack of muscles provides more room in the owl’s head for larger eyes, but the eyes are now “stuck” permanently facing forward in a stationary position. To overcome this drawback, the owl has nine vertebrae in its neck (man has only seven) allowing it to turn its head almost 360 degrees (man can barely turn his head 180 degrees).
Four, scientists now believe that many birds, especially predators, can see ultra violet light (man cannot). Apparently, most rodents’ waste (urine and feces) give off ultra violet light which the owl can see and thus help it to zero in on its prey.
Five, anybody who has seen an owl or a picture of one is always struck by the eyes being surrounded by a disc or dish of feathers giving the bird its “owl” look. These feathery discs are not cosmetic in nature, but are sound gathering devices much like the dishes people use to receive satellite signals. These discs amplify the quietist of sounds so that an owl can hear a mouse scurrying across a forest floor quite some distance away. In addition, the ears are offset a little forcing sounds to reach the ears at slightly different times. The brain is then able to process the sounds so that the owl can focus on the origins of the sounds with great precision. In fact, in several experiments owls were able to catch rodents in buildings where there was absolutely no light. They did it by hearing alone!
This week’s featured bird is the smaller of our two “eared” owls – the Long Eared Owl. This slender crow-sized owl is very secretive. Being nocturnal it is commonly seen, if seen at all, in the daytime hugging the trunk of a tree usually in dense brush. Even though it is quite common it is often overlooked.
The “ear” tufts are not ears at all but feathers that are there for purely cosmetic reasons. This is one of the few owls that actually “hoots”, but it also barks like a terrier if it or its young are threatened.
The Long Eared Owl occurs throughout the northern hemisphere north to the tree line. It usually stays away from deep forest preferring to live at the forest’s edge, or in prairie bluffs – especially if evergreens are present. It nests almost exclusively in old crow’s nests. By knowing where crows nested one year can be quite helpful in finding a Long Eared Owl’s the next.
I was lucky enough to see and get a photo of this week’s bird at San Elijo Lagoon just north of San Diego. This owl is somewhat migratory and, in the winter time, can only be seen in the southern part of our province.