Bird Migrations

 

On April 18, 2013 a very interesting presentation was given by Tom Allen for the Lake Superior Elders covering bird migration.  He began the presentation by describing the meaning of migration which is a periodic movement that is conducted on a regular basis.  The two reasons why migration occurs is: exploit ecological opportunities; and leave when things get bad.  Upper Michigan is desirable because of the insects which are flying protein, worms and fish.  The crows in this area also chow on other birds because I found the feathers of a seagull that was being hunted by crows in our yard and dead deer alongside the road.  The Savannah Sparrows eat bugs that are on the ground such as ants.  We get a lot of these in our yard.  Osprey build a nest at the end of our road on a tower every year, their young are born and they depart in the fall or late summer.  Our whole neighborhood watches them. A robin builds a nest under our front deck every year and hatches several eggs each summer.  Robins migrate from Ohio and are not a native bird of Michigan, even though they are our state bird.  I found out that the only bird that is native to Michigan and is only seen in Michigan is the Red winged Blackbirds. 

Tropical birds that come North, come north to mate and are only here for a short amount of time.  Blue birds travel from Ohio to come here to mate.  Some are nocturnal, feed during the day and travel at night and some only travel during the day.  Before they travel they gain a lot of weight so they can fly for long periods of time.  Fat converts to water.  Some birds fly for over 30 hours such as birds who fly over the ocean.  That’s stamina.  The Bobolink is a long distance migratory who travels from South America to North America.  They travel 12,000 miles per year and return to the same field each year. 

Mr. Allen told us about how birds know in which direction to travel.  A study was conducted in a planetarium and when the direction of the stars was changed the birds changed their direction of flight.  There have been determinations that birds use an internal sun compass and also magnet coordination.  How does someone find their way home in a snow storm?  Some people have magnet coordination, a magnetic orientation.  Other animals such as cats and dogs have managed to find their way home.  Some of the researchers believe that some birds have a sense of smell.  Land birds don’t like flying over water and water birds prefer flying over water.   

The Whitefish Point Bird Observatory has been in operation for many years.  The studies began on July 6, 1912 when Norman Wood was accompanied by his wife and daughter arrived at Whitefish Point to examine bird life.  He was sent by the University of Michigan’s Museum of Zoology.  Wood collected and catalogued specimens and gathered data on the abundance and variety of birds.  A total of 163 species was recorded over his two year study.  He began the first studies at Whitefish Point.  In 1937, Samuel Knox, a student at the University of Michigan submitted a detailed report on the hawk flight at Whitefish Point. His records indicated that he observed ten different species of raptors at the Point. Whitefish Point is one of the most important spring flight corridors for raptors in North America. The 163 species that Wood recorded has increased to over 330 today. 

At Whitefish Point the spring owl banding runs annually since 1988 and is held from 1st to the 31^st in April.  The nets that are used to trap the owls resemble the mesh of a hair net.  The owls are caught and bands are placed on them.  Two owls were reported as returning this year.  There were 99 Great Gray Owls caught this year in the nets last Friday evening when the weather was on the verge of getting nice. This has been a horrible winter.  This is the spring breeding population. 10,000 Loons were and 30,000 ducks were observed at the Point.  Fall banding of owls began in 1993 and is held from September 15 to October 31^st of each year.  Calls are broadcasted to lure the owls into the nets.  This increased the capture rate and sample size.

Israel is known to be the world authority on bird migration.  The Israeli Air Force has enrolled the Birdstrike Control Program to provide them with professional comprehensive wildlife control.  Prior to their involvement the Israeli Air Force suffered on average $10 million in damaged due to bird strikes over a nine year period, costing roughly $84 million.  They have virtually eliminated the large and medium sized birds from the airbases and have reduced the smaller bird populations by approximately 90 percent.  Israel used to serve as a main corridor for bird migration. 

The Migratory Bird Treaty of 1913 placed control of the migratory birds under federal governance.  For example, duck hunting is determined by states, duration and time of hunts can be conducted; however the federal government determines how many ducks can be hunted.  Canada and the United States work together to make determinations concerning how many ducks can be hunted.

Allen informed the audience about bird deaths.  The Renaissance Center in Detroit reported that 4,000 birds died because they flew into the lights on top of the building.  Many of the large buildings in the cities are turning off their lights at the upper levels to protect the birds.  Wind power has caused problems for birds.  There was a discussion about cats killing five million birds, feral cats.  My husband stated this is the fault of humans who don’t take care of cats.  They need to be spayed and neutered to decrease the population.  More pheasants were killed by cats then by pheasant hunters according to Allen. 

If you are interested in tracking bird migration you can follow the radar services provided by Marquette and Gaylord.  The individuals associated with these weather programs are only interested in cloud formations and other weather details; but bird migration can also be observed by using these sites.  The sounds specific birds make were recorded and when birds fly over the sounds they make determine what kind of birds they are. 

I have always been interested in observing birds and found this presentation to be very interesting. There are many books available and internet sites to explore to learn more about birds.  Now I want to visit the bird observatory at Whitefish Point.  I remember reading the sign when I visited the light house; however now my interest is sparked.