Wednesday, September 30, 2015

PASSENGER PIGEONS

Young bird, male, female

If you are waiting for a passenger pigeon to come and roost in your back yard, you might as well forget about it because passenger pigeons are totally and completely EXTINCT.  The last passenger pigeon, who was named Martha, lived in the Cincinnati Zoo, and she died of old age on September 1, 1914.  She might have been 17, 18, 19, 20, 27, 28, or 29 years old when she died, but it is usually said that she was 29.

Martha in her enclosure, 1914

After Martha died, her body was sent to the Smithsonian, where she was mounted.  She was scheduled to be on display through September 2015 at the National Museum of Natural History as part of an exhibit called "Once There Were Billions."  A memorial statue of Martha stands on the grounds of the Cincinnati Zoo.

Martha at the Smithsonian, 1956

It is true that there used to be billions of passenger pigeons in North America.  They were the most abundant bird on this continent and maybe in the whole world.  Their name came from the French word passager, which means "passing by."  They were very social birds who lived in huge flocks that migrated from place to place, mainly in northeastern and north central North America.  One flock in 1866 in southern Ontario was described as being 1 mile wide and 300 miles long.  It took 14 hours to pass over, and it included more than 3.5 billion birds.

Painting by Walton Ford; Photographed by Butcher Walsh
http://www.newyorker.com/magazine/2014/01/06/the-birds-4

Passenger pigeons lived in deciduous forests east of the Rocky Mountains.  They nested in places with lots of oaks and beech trees that provided "mast," which means acorns and nuts and other such edible stuff that trees produce.  In a "mast year," there is more mast than usual, so the pigeons migrated to the places where there was the most mast for them to eat and feed their young.

The birds usually arrived on their breeding grounds in March, April, or May.  Nesting areas could range in size from 120 acres to thousands of hectares in size.  The largest breeding colony ever recorded was in central Wisconsin in 1871.  It was about 850 square miles in size with an estimated 136,000,000 birds nesting there.

Audubon

There could be more than 50 nests in each tree.  The female chose the site, and the male brought twigs to her to build the nest with.  The twigs were woven together to make a nest about 6" wide and 2.4" deep.  Each female laid a single egg.  It was incubated for 12 to 14 days.  The male sat on the nest for several hours in the middle of the day, and the female sat on it the rest of the time.

The baby bird grew quickly and within 14 days, it weighed as much as its parents.  After 15 days or so, the parents abandoned their nestling.  It begged for a while, then fluttered to the ground.  In 3 or 4 days, it had all its feathers and could fly.  By the following spring, the new baby was sexually mature and could breed.

Hatchling, 1896

Nesting colonies attracted lots of predators such as weasels, minks, martens, raccoons, wolves, foxes, bobcats, bears, mountain lions, hawks, owls, and eagles.  Some of these predators ate the eggs, others ate the nestlings, and some went after injured adults.  In spite of this, there were such huge numbers of passenger pigeons that predation did little damage to the size of a flock.

Passenger pigeons were good fliers and could migrate long distances.  They liked to spend the cold weather in swampy areas.  Sometimes so many birds would roost on one branch that the branch broke.  They often piled on each other's backs to roost and rested in a slumped position that hid their feet.  Under a roosting site, there might be a pile of dung a foot deep.

"Falling Bough" by Walton Ford
http://www.vox.com/2014/9/1/6079675/passenger-pigeon-extinction

The pigeons changed their diet according to the season.  During fall, winter, and spring, they ate mostly beechnuts, acorns, and chestnuts.  In summertime, they ate berries, earthworms, caterpillars, and snails.  They also liked to eat cultivated grains such as buckwheat, when those were available.  Of course, farmers did not like it when the birds ate their crops or even when they ate all the acorns that would have fed domestic pigs.  Another thing pigeons were fond of was salt, which they got from salty soil or brackish water.  Every day the birds left their roost to forage for food, sometimes flying as far as 60 to 80 miles.

So with billions of passenger pigeons, how did they go extinct?  One thing that happened was that people started cutting all the forests down, so there weren't as many places for the pigeons to nest and roost.  Also, there weren't as many nuts to eat.  Portable saw mills, which began to be used in the 1870s to clear-cut forests, speeded up this process.

"Passenger Pigeons" by Louis Agassiz Fuertes
http://www.allaboutbirds.org/never-to-be-repeated-lessons-from-the-passenger-pigeon/

At the same time, pigeon meat became popular.  Native Americans had always hunted pigeons, but they usually only ate juveniles and did not disturb the adults.  Early colonists found pigeons to be an important food source for common people and slaves.

It was hard to know where the pigeons would show up because they were always migrating, but the telegraph solved this problem, and hunters could find out easily where the flocks were.  Also, the railroad provided an easy way to ship pigeon meat back east, where it had become a delicacy.  So hunting the birds became profitable, and hunters found ways to kill thousands of them quickly and easily.  Trees were sometimes set on fire using toxic substances which the birds inhaled and died.  Nets could be set up which were partly open, and a few pigeons were blinded and tied to stools inside the net.  These "stool pigeons" fooled other birds into thinking there was food there, and then they would be caught in the net.

James Pattison Cockburn, 1829

Even larger numbers of pigeons could be killed by shooting them.  A good blast with both barrels of a shotgun could bring down as many as 60 birds.  They could be shot during migration or while they perched in bare trees.  Sometimes a trench was dug and filled with grain.  Then the pigeons were shot when they came to feed.

In 1878, at a nesting site in Petoskey, Michigan, 50,000 birds were killed each day for almost 5 months.  One hunter was reported to have sent 3 million birds to eastern cities during the course of his career.


Eventually, the passenger pigeon population reached such low numbers that the species could no longer survive, even though there were quite a few birds left.  People have suggested cloning the passenger pigeon from existing DNA, but this would probably not work because there would not be a big enough population of birds to keep the species going.  Plus, you would have use other types of pigeons as parents, and they would have different methods of raising their young, so it would all be very confusing for the birds.

A famous naturalist named Aldo Leopold spoke at the dedication of a monument to the passenger pigeon at the Wyalusing State Park, Wisconsin on May 11, 1947, and here's what he said:

Men still live who, in their youth, remember pigeons.  Trees still live who, in their youth, were shaken by a living wind.  But a decade hence only the oldest oaks will remember, and at long last only the hills will know.


Louis Agassiz Fuertes

2 comments:

  1. Beautiful and very colorful PIGEONS these are, i mean i like this art.

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    Replies
    1. Yes, they were very beautiful birds. It is sad that they are now extinct.

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