Sunday, September 5, 2010

Fall is in the air!

How to tell its fall!! Here in Wisconsin, we have had one of the hottest summers on record and statistics are similar across the country at least from the Rocky Mountains east to the Atlantic coast. But a front has gone through and now the air is cooler, there is a wonderful breeze! Some people would call it a wind. We are opening the windows and turning off the AC. This year's two young eagles are practicing their flying. One landed on our neighbors' chimney and my husband caught a picture or two. It is still so exciting to see those birds as our neighbors here on Lake Michigan.  The purple coneflowers outside my dinette window are turning chocolate brown as they end their flowering season. But there are gold finches in droves on the seed heads. The gold finches nest late and therefore are probably still feeding their fledgelings. I hear our neighborhood bluebirds occasionally give their bubbling song and they are hunting in our backyard. Of course, these may be northerners moved in on their way south. Today I heard a wren singing. That usually doesn't happen in September. The little bird must feel the same invigoration that I feel with the lowered temperatures and humidity. A hummingbird is making the rounds of the flower heads. It comes around the corner of the dinette where there is a window cranked widely open to catch the refreshing breeze. The little buzzing bird stops in midair as only they can do and looks in the open window. It obviously sees something different than its usual rounds. Then it quickly moves on. These little birds with their high metabolism and need for constant nutrition, with their complex tiny brains that keep track of all the flowers they visit and the time it will take for each flower to reacccumulate its nectar, can notice tiny little changes on their daily rounds. There are apples on our flowering crabapple tree and every morning a doe and her two half grown fawns visit the tree to get what apples they can, the doe standing on her hind feet to reach those on the lower branches, the fawns of course eating off the ground. I haven't seen any signs of the males yet but that will come shortly as the males enter the rutting season. They will strut across our yard, neck muscles standing out and looking like kings of the deer world, seeking the females that are receptive.  Monarchs are starting to move south along the Lake Michigan bluff. I must remember the broad wing hawk migration at Concordia University along Lake Michigan. It is usually around September 18 or within 5 days each side of that date, when a cool front with a Northwest wind moves through moving those birds up against the lake shore. Then a viewer might be privileged to see kettles of hawks circling over head and slowly peeling off to move further south. Why do these kettles as they are called form? Raptors generally don't like to fly great distances over water. They rely on thermal updrafts to help them rise and not as many thermals develop over water. Since the broad wings all migrate at about the same time which is a specie specific trait, there will be 100s of these birds in each thermal creating these circular formations of birds. Each individual bird rises to the top of the thermal and when the rising hot air cools and ceases to rise the bird peels off the top of the air column and glides, losing height until it finds the base of another rising air column. This formation resembles a kettle boiling over. Hence the name -- a kettle of hawks.

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