Nightime Eyes

Here in Florida, even those who seldom venture outside because of the heat and are prisoner to their air conditioning would have to be blind to not notice that we live in the land of birds, lots of birds, despite urban sprawl. We have them all, Sand Hill Cranes, Morning Doves, Sea Gulls, Pelicans, and just about twice as many winter birds, as we have snowbirds of the human variety.

Back in West Virginia on our farm, I had a daily reminder of certain birds of the night. Here in Florida, they sit on glimmering tiled roofs in the same darkness, no doubt warmed by a day in the sun. The difference between the two, is that the owl I saw the most in West Virginia was dead, one eye hanging out -- a road kill my husband had brought home, enveloped in clear plastic, waiting his turn at being turned into stuffed wall art, waiting to greet me every time I opened the freezer.

The great majority of birds without night time eyes are by choice diurnal in habits. By diurnal, I mean that they are active by day and sleep at night. Some species always sleep through the hours of darkness and only take to wing when forced through dire emergency.

Others, however, switch to night flying for journeys of migration. Observers along migration flyways have reported that fluttering silhouettes of untold thousands of birds cross the face of a full moon.

Another proof of flights during darkness, comes from the keepers of the world lonely places. In times past, the keepers of lighthouses put up nets from which the birds could bounce without harm.

A few species of birds are equally active in any degree of light. The island nesting Shearwaters, Petrels, and Auklets never approach their homes during daylight hours, but at dusk and just before dawn the parents trade places on the eggs. The mate that has been hunting at sea comes home to "babysit" while the one that has been at home flies off in search of food.

Then there are the unrelated species such as Mockingbirds, Ruffed Grouse, and the Nightingales of Europe that are almost strictly bird with nigh time eyes. They carry out most of their affairs during the cover of darkness, including their audible courtship.

Thus, in some parts of the world, the drumming produced by rapidly moving wings of a Ruffed Grouse may be detected as often at night as during the day. The song of the Mockingbird seems to burst forth at night with a fuller quality of tone than the same bird song voiced when the sun is shining. This effect may be due to the absence of other noises. However, perhaps the bird's romantic song at night is really a more glorious solo.

All the birds that I've mentioned before are mainly diurnal. They are mentioned in the same breath of night birds because they do engage in some activities by night.

There are several other bird families that completely reverse this process. Their habits are nocturnal -- that is, they sleep by day and carry on their entire lives by night.

Wonderfully Mysterious Nocturnal Birds of the Night

There is something almost mysterious about these little bird creatures of the night. They are better known by ear than by sight. Perhaps you've heard unidentified sounds at night floating down from the sky. Such noises are bound to whet the appetite for more knowledge.

It could have been the zoom of a Nighthawk spreading his wings at the termination of a dive and letting the rushing air vibrate his primary feathers, or it might have been the whistle of a Screech owl, or maybe the raucous squawk of a Night Heron winging its way to a marsh or swamp.

The night birds include two orders Strigiformes (owls) and Caprimulgiformes (goatsuckers, whippoorwills, and nighthawks).

Of all birds, owls are the most widespread. They have sharp beaks and powerful legs and feet, with strong talons for grasping prey. They are meat eaters. They will swallow their prey whole. The parts of the victim that they can't digest, such as hair and bones, they will bring up and spit out in pellets.

Their heads are large and piercing, facing forward, are equally large and piercing eyes that are ringed by discs of stiff feathers.

The outer toe of the owl may be directed backward, to give a good grip when the bird is perching, and to help in grasping prey.

Some owls do not migrate, but others make long journeys in the spring and fall.

There Are Some Families of Owls Everyone Should Know

The Barn Owl is the first kind of owl everyone should be familiar with. They have white faces and dark, staring eyes, which give them a dramatic appearance.

They are found, with slight variations, in many countries of the world.

Their diet consists almost exclusively of rodents, and so they may be considered the world's most beneficial birds.

Sounds made by scampering mice or rats would naturally be less audible in damp grass or leaves then when the foliage was dry and brittle, as the ear openings on all owls are extremely large -- they no doubt do much of their hunting by ear.

Another interesting fact about Barn owls is that their diet seems to be influenced by the action of moisture on their feathers. In dry weather most owl feathers are extremely soft and the birds fly through the air on almost noiseless wings. When these feathers are wet, however, they give an audible swish with each beat -- a noise that perhaps warns the prey in time to escape the clutching talons.

In heavily wooded areas of the United States and Canada, the Horned Owls are the most common birds of the night. Their call, a mournful Whoo-ho who--whooo--whoo is so well-known that most people believe that all owls hoot. This is not true!

While a number of owls hoot, other have a whistling call. Still other owls have a shrill screech, like a high-pitched laugh.

Horned owls are large birds standing about two feet tall. They live to a great extend on wild rabbits. In the east, this choice of food has put them on the black list with hunters. In some states, they are allowed to be hunted in season.

In the west, however, where rabbits are considered a pest destructive to agriculture, the Great Horned Owls are really beneficial. This owl gets its name from the two tufts of feathers on the head that resemble horns.

Some owls have become highly specialized for life in the areas where they live. The Snowy owls, for instance, reside in the far north, often in a treeless land of almost perpetual ice and snow. To support their weight on the snow, the feathers of the feet run clear to the talons and spread to form miniature snowshoes.

Many of the small mammals and birds of this northern region are colored to match the white background. Therefore, a dark colored owl would be at a great disadvantage in foraging for food. The Snowy Owl, as the name implies, is adorned with white feathers -- a condition that puts hunted and hunter on an equal basis.

Every seven or eight years plagues seem to hit the wild rabbits of the far north and reduce the population to a minimum. In those years, when food becomes scarce, the Snowy Owls migrate southward from northern Canada and invade the United States.

However, in the southern latitudes, their white bodies show up like billboards. The birds become targets for every thoughtless hunter with a gun. As a result, they are now a protected owl in the United States.

The tiny Elf Owl, a sparrow-sized bird, the smallest member of this nocturnal bird family, is found only where the giant saguaro cactus thrives. This bird is so small that it nests almost exclusively on insects, scorpions, and other similar prey.

During its nesting season, in June, the daylight temperatures in the desert where it lives, often soar to over one hundred and twenty degrees or more. These mites of the owl world, however, sleep away the hot days, surrounded by an insulated wall -- the damp, pithy shell of a saguaro cactus. They only venture forth after dark.

The Burrowing Owl, a long-legged member of the owl clan, can survive on the treeless prairies. It is one of few birds that lays its eggs and raises its young in an underground chamber. Although the name falsely implies that this bird is capable of digging -- it is actually dependent on the deserted burrows of small mammals.

Occasionally, rattlesnakes seek similar retreats for winter hibernation. Thus, bird and snake depend upon the burrowing mammal. This three way association has brought about the myth that they all live together in perfect harmony. This is not so.

In the fall of the year, rattlesnakes sometimes select prairie dog burrows in which to sleep away the winter months.

However, there has never been any reliable evidence that either the prairie dogs or the owls make use of these burrows after the rattlesnakes have taken over.

In the spring, the owls select a deserted burrow and plug it at the depth of two or three feet. When the eggs are laid within this tunnel, they will use their sharp talons to drive away prairie dogs, rabbits, or any other small mammal that approaches.

The young owls in their underground next have a call, when disturbed that so closely resembles the buzz of angry rattle snakes -- that only an expert can tell the difference. This has given rise to the fiction that Burrowing owls and rattlesnakes live together as one big happy family.