Autumn Leaf

autumn leaf, originally uploaded by donnallong.

The leaf is luminous. I like the sunlight highlighting the veins at the top of the leaf. I like the lack of perfection.

This leaf looks as it has had a life well lived. But, it's life is over now. Human life is the same way. If we don't live life like we mean it, then what is the point?

Bird Migration Routes - Do You Live Near One?

Flyways map courtesy Fish & Wildlife Service

Flyways are heavily traveled routes bird use during migration. During migration, birds tend to follow physical features such as coastlines, mountain ranges and river valleys.

In the 1930's investigators became impressed by what appeared to be four broad, heavily traveled "highways" in North America. This concept was based on several thousand records of migratory waterfowl.

The "highways" were only approximate and many birds migrate outside of them.

W.W. Cook identified seven generalized routes for birds leaving the United States on their way to various wintering grounds (see map above). The routes by which birds return northward in the spring are not as well known.

Look over the following list and the map above to see if you live on or near a migration route. 

Main Migration Routes in North America

Atlantic Oceanic Route (route 1) This route mostly travels across the Atlantic Ocean. It stretches from Labrador and Nova Scotia to the Lesser Antilles, then through a small group of islands to the mainland of South America. Since this route is almost entirely over water, the only way humans know about it, is through observations on islands like Bermuda and those islands along the way. Birds usually fly this route by both day and night.

Atlantic Coast Route and Tributaries (route 2) The Atlantic coastline is a regular route of travel. It has many famous birding hotspots for observing both land and water birds. About 50 different kinds of landbirds that breed in New England follow the coast southward to Florida and travel by island and mainland to South America. At no time are these air travelers out of sight of land. It is not however the favored migration highway. Only about 25 species of birds use this route to go to their winter homes beyond Cuba to Puerto Rico. This was known as the Atlantic Flyway. This is the route that covers the sky over Philadelphia, Delaware and the Jersey Shore.

Mackenzie Valley-Great Lakes- Mississippi Valley Routes and Tributaries (route 3) This migration route is the longest of any in the Western Hemisphere. It extends from the Mackenzie Valley past the Great Lakes and down to the Mississippi valley. Its northern end is on the arctic coast in the regions of Kotzebue Sound, Alaska and the mouth of the Mackenzie River. The southern end lies in Argentina.

For more than 3,000 miles, from the mouth of the Mackenzie to the Mississippi delta, this route is uninterrupted by mountains. Because it has plenty of trees and water, the area is a great place to view great numbers of migrating birds. During the height of migration, going to birding hotspots in the Mississippi Valley, allow birders to can see large numbers of many species. Swarms of birds are spotted on the islands off the coast of Louisiana. This was known as the old Mississippi Flyway. (route 4)

This route begins in the Mackenzie River delta in Alaska. Some places in this area, such as the National Bison range at Moise, Montana, have food in such abundance that birds stop here during migration to refuel. This was known as the old Central Flyway.

Pacific Coast Route (route 5) The Pacific Coast Route is not as long or heavily traveled as some of the others. Because of the nice living conditions, many species of birds breeding along the coast from the northwestern states up to southeastern Alaska either do not migrate or else make short journeys. This route has its origin chiefly in Western Alaska around the Yukon river delta. Large numbers of arctic-breeding shorebirds also use this route. This was known as the old Pacifc Flyway.

Pacific Oceanic Route (route 6) This route is mainly over water. It extends from the islands of the Bering Strait through the islands of the central Pacific and northward along the Asiatic Coast. Many seabirds that breed in the far northern coasts, southern coasts and islands migrate across the Pacific away from land and except when the breeding season approaches. Incredibly, birds navigate to tiny isolated islands in the middle of the vast Pacific Ocean.

Arctic routes (route 7) Some arctic nesting birds travel only a short distance south in winter. They fly mainly along the coast. The best defined arctic route in North America follows the coast of Alaska.

More Information:
Flyways.us
http://www.flyways.us/flyways/info

Information courtesy of: "Migration of Birds: Routes of Migration",http://www.npwrc.usgs.gov/resource/birds/migratio/routes.htm March 09, 2007. 

The Autumnal Equinox and Fall beigns

The autumnal equinox starts the fall season. It occurs on September 22 or 23 each year. The "fall" is my favorite time of the year. The crisp cool air and brilliant colors of the leaves urges me outside with camera in hand.

There are two equinoxes a year. One in spring and the other in autumn. The spring (or vernal) equinox happens on March 19, 20, or 21.

The seasons are reversed in the northern and southern hemispheres of the planet. When the northern hemisphere experiences autumn, the southern hemisphere is experiencing spring. 

On the equinoxes, the sun is directly above the Earth's equator. Day and night are of equal length all over the planet. The world receives twelve hours of daylight and twelve hours of darkness. The term equinox comes from the Latin and means "equal night".

The seasons signal that changes in length of daylight, temperature and weather are about to happen.

The seasons are caused by the changing position of the Earth in relation to the Sun. The Earth receives different amounts of sunlight during the year due to the tilt of the Earth. The Earth is like a spinning gyroscope and always points in the same general direction. The earth is tilted on a 23.5° degree angle and the sun shines on the planet  in a particular way. The north pole is generally tilted toward the north star and the south pole tilts toward the constellation of Octans.

Cold Days and Short Nights

The Autumnal Equinox begins the cold months. During the colder months, the North Pole is at it's greatest tilt away from the sun. The northern hemisphere then has colder temperatures, short days and long nights.

It takes a few weeks for the weather to change after the beginning of a new season. During autumn, there are alternating warm and cool days and cooler nights for several weeks.

On the day of the Autumnal Equinox, the Sun is positioned directly over the equator.  After this day, the northern hemisphere begins to tilts away from the sun. The weather becomes colder and the hours of daylight become shorter. This culminates in the shortest day and the longest night of the year, the Winter Solstice on December 22 or 23. Then the days grow longer until the Summer Solstice.

In 2010, the Autumn Equinox happens on September 22nd.