The Passenger Pigeon

 

Once upon a time, North America was home to an estimated five to eight billion passenger pigeons.  They may have been the most numerous bird species in the world.  My father was in diapers when the last one died in 1914.  I was born in Michigan, where immense flocks had once thrived, prior to the invasion of farmers and loggers in the early 1800s.  Today, our culture has largely forgotten the saga of the passenger pigeons.  We still remember the war on bison, which is somehow seen as more heroic and dignified.

Lately, some genetic engineers have been talking about resurrecting the extinct birds.  Huh?  Would that make any sense?  Their natural habitat is long gone, and their return would not be appreciated by farmers, airline pilots, and many others.  Curiosity forced me to read two pigeon books.  It was an illuminating and disturbing experience. 

A. W. Schorger (1884-1972) wrote The Passenger Pigeon, which especially impressed me, because he was totally obsessed with this subject.  He devoted 15 years to research, exploring over ten thousand sources — books, journal articles, newspaper clippings.  He actively sought informants, and corresponded with many old-timers who had been near the front lines in the war on birds.  Passenger pigeons inhabited the eastern U.S., and southeastern Canada.  Wikipedia provides a good overview, and a map of their habitat [HERE]. 

Their primary source of food was mast — nuts, seeds, berries, and fruit produced by trees and woody brush.  The two most important foods were acorns and beechnuts.  Acorns were swallowed whole, and up to 17 could be stored in the bird’s crop.  By morning, they would be digested.  When winter grew old and tired, flocks migrated northward, as the retreating snow exposed a buried treasure of yummy nuts.

Pigeons also raided farms.  In the early days, at planting time, seeds were broadcast by hand (tossed on the ground surface).  Then, hungry flocks would zoom in and eagerly devour them all.  They loved corn and wheat, but buckwheat was their favorite.  Farmers sometimes burned thousands of acres of trees to discourage flocks from roosting close to their fields.  Later, they switched to sowing devices that covered the seeds with soil.

Flocks did not visit the same areas annually, because oak and beech forests did not reliably produce nuts year after year.  Birds might not return to the same place for 11 years.  Nut trees were smart.  By being unpredictable, hungry flocks could not become permanent parasites.  This enabled enough nuts to germinate, sprout, and maintain the survival of the species.  For pigeon flocks, life was a never ending search for free lunches.  They followed their stomachs to delicious locations. 

Observers calculated that enormous flocks zoomed across the sky at about 60 miles per hour (96 km/h).  They constantly scanned the land they flew over, in search of nourishing treasures.  Flocks were most vulnerable when on the ground, where they were prey for predators like wolves, foxes, lynxes, cougars, raccoons, and humans. 

They were far safer when perched in trees, or flying.  Airborne predators included eagles, hawks, and vultures.  A solitary pigeon would have been an easy lunch.  It was much safer to fly within a fast moving mob of a million friends.  Large flocks were not one solid mass, they separated into multiple tiers of birds, layers maybe spaced a foot apart (30 cm).  At high speed, these densely packed clusters moved fluidly in unison — swerving, diving, soaring, and bending.  This made predation difficult.

Large flocks of birds required large amounts of food, so they had to keep moving.  Nights were spent safely roosting in trees.  In the morning, smaller groups scattered across the land to forage.  They might travel 100 miles (160 km) before returning to roost for the night.  If one group discovered a location that contained abundant food, the larger flock would somehow learn this, and join the feast.  When a banquet concluded, the flock took wing and searched for a new place to roost for a while.  Passenger pigeons were nomads, no permanent address.

In Kentucky, observers described a huge roosting site 40 miles (64 km) long, and 3 miles wide.  When large flocks roosted, birds covered every limb, sometimes several layers deep, standing on the backs of others.  Their weight snapped off large limbs.  Sometimes entire trees fell over.  Some forests looked like a tornado had passed through — thousands of acres of dead trees.

Descriptions of migrating flocks, in unbelievable numbers, strain the imagination.  But millions of people saw them.  Flocks often stretched as far as the eye could see, from horizon to horizon.  They might block out the sun for several days.  People could hear the approach of flock that was still 4 miles (6.4 km) away.  The sound of a million wings was deafening, “like the roar of distant thunder.”  John James Audubon, naturalist and artist, calculated that one flock had more than a billion birds.  Someone else watched a flock in Kentucky that sped across the sky for 14 hours.  It was a mile wide and more than 300 miles (483 km) long.  The flock continued on the following day. 

Roosting sites were inhabited until food in an area became scarce, then the flock moved on.  Nesting sites required a longer stay, so they were located where food resources were especially abundant.  They were close to water, sheltered from the wind, and often on islands.  A vital process was performed at nesting sites, reproduction.  Nests were built in trees, eggs laid, and squabs (chicks) hatched.  Flocks nested at least once a year, and most observers reported that just one egg was laid per nest. 

Nesting sites varied in size, but large colonies were typical.  There was safety in numbers.  Pigeon cities could have a hundred million birds or more.  They might inhabit an area ten miles long and three miles wide (16 by 4.8 km).  Tree limbs were crowded with nests.  If a winter storm blew in, or if hunters began shooting, the entire colony might suddenly abandon their nests and squabs.

Nesting was synchronized.  Colonies gathered and nests were built.  Almost all of the eggs were laid on about the same day.  Parents took turns keeping the squabs warm under wing, while the other parent brought back food.  Squabs grew rapidly, remaining in the nest for 13 to 15 days.  At this point, parents brought squabs their last meal, and then departed from the nesting area in a great mass.  It was up to the squabs to learn how to fly.  They were fairly helpless, and predators were happy to eat them.  Their bodies were loaded with fat. 

Native Americans were grateful for the pigeons.  They caught birds with nets.  Nesting sites were primary locations for getting birds.  They used poles to knock squabs from their nests.  Nesting trees were sometimes cut down to access the numerous squabs.  Tribes collected the fat from squabs, stored it, and used it like butter.  Pigeons played starring roles in tribal myths and legends.  There were taboos against prematurely disturbing nesting sites, and scaring away the adults before the young had hatched. 

Early explorers (1534) reported large passenger pigeon populations.  They were the most common birds on Manhattan Island in the 1620s.  In the 1800s, the tide changed.  Settlers were encouraged to conquer and demolish the wild frontier.  In 1849, free land was given to folks who drained wetlands (prime nesting habitat).  New telegraph systems enabled social networking, announcing the location of nesting sites.  New railroads enabled industrial scale pigeon hunting.  Millions of birds could be quickly shipped from rural areas to big cities.  Sometimes tons of squabs were dumped in the river due to spoilage.  Unsold birds were fed to pigs.

Hunters used ducking guns with six foot barrels, double barrel shotguns, and large blunderbusses.  A single shot might kill 132.  A Wisconsin hunter shot 1,458 birds in one day.  Lads skilled with nets could capture up to 6,000 birds per day.  Many birds were killed for their feathers alone, which were used for bedding.

By the 1870s, bird numbers were obviously declining.  Some folks suggested conservation efforts, but few really gave a <bleep>.  Money makes civilized people crazy, and an ambitious lad could make big money selling squabs for 30¢ a dozen.  The last wild flocks were gone by 1889.  They had been massacred far faster than they could reproduce.  Schorger sighed, “Persecution was unremitting until the last wild bird disappeared.” 

Over and over again, natural history teaches us that genetic evolution works slowly and beautifully.  When the species in an ecosystem coevolve over the course of thousands of years, the journey is far more likely to develop a sense of balance and harmony.  Over and over again, reality teaches us that a society obsessed with wealth and status is a fast path to a dead end.  Why don’t schools teach this?  How can we see where we’re going if we don’t know where we’ve been?

Schorger, Arlie William, The Passenger Pigeon, 1955, Reprint, University of Oklahoma Press, Norman, 1973.

Greenberg, Joel, A Feathered River Across the Sky, Bloomsbury, New York, 2014.  

Wild Free and Happy Sample 03

[Note: This is the third sample from my rough draft of a far from finished new book, Wild Free & Happy.  I don’t plan on reviewing more books for a while.  My blog is home to reviews of 196 books, and you are very welcome to explore them.  The Search field on the right side will find words in the full contents of all rants and reviews, if you are interested in specific authors, titles, or subjects.] 

The Primate Clans

Primates include both apes (no tails) and monkeys (tails).  Over the eons, different primate species evolved in different ecosystems.  Each location had a different mix of climate, food resources, advantages, and dangers.  These variables encouraged unique evolutionary adaptations.  The adaptations that best increased the odds for survival were more likely to be passed on to the following generations.  Each ecosystem was also in a process of endless change, sometimes slow and gradual, and other times fast and extreme.  Over time, in response to change, primate evolution fine-tuned beneficial adaptations, and abandoned the duds.

Since Neanderthals disappeared from the stage, our closest living relatives are the chimps and bonobos, with whom we share up to 99 percent of our genes.  Next closest are gorillas, and in fourth place are orangutans.  The ancestors of all four relatives have inhabited tropical forests for millions years without trashing their ecosystems.  Mainstream culture teaches us that they are less intelligent than we are (an advantage?).  Unfortunately, evolution has not outfitted them with bulletproof hides to protect them from bushmeat hunters and crabby farmers.  They do not instinctively mob and exterminate loggers, miners, and developers.

Let’s take a peek at a few of our primate relatives.

Snow Monkeys

Japanese macaque (snow monkey) habitat ranges from sub-tropical to sub-arctic.  In their sub-arctic locations, temperatures can dip to -4°F (-20°C).  Snow might cover the ground for four months, in depths up to 10 feet (3 m).  As winter approaches, their summer fur grows and thickens into gorgeous insulated coats.  Bands sometimes take a pleasant soak in a hot spring, on a snowy winter day.  They have been observed at elevations as high as 10,433 feet (3,180 m).

During the summer, they build up body fat by feasting at the warm season buffet, which includes the fruit, seeds, nuts, the vegetation of 213 plant species, and the crops of crabby gun-toting farmers.  They also dine on fish, insects, and invertebrates.  In winter months, they survive on stored body fat, and rough foods like leaves and bark.  They huddle together to keep warm. 

Hominins (human ancestors) evolved for life in the tropics, where there was no need for warm fur.  When they migrated into non-tropical regions, life got dangerously chilly.  To survive in snow country, they needed warm clothing and shelters — technological crutches that require tedious time-consuming toil that was completely unnecessary in their natural habitat.  They did not gradually move out of warm lands, and let evolution perfectly fine tune them for cooler places.  They were already extremely unusual high-tech critters, with their thrusting spears and domesticated fire.  They impatiently bypassed evolution.  Oh-oh!

Baboons

When climate change shrank the forest and expanded the savannah, the ancestors of baboons evolved in a way that allowed them to spend much of their time on the ground.  Few of them now live in tropical forests, but all baboons have retained the physique for scampering up trees.  Baboons intelligently avoid wild predators by sleeping at the top of steep cliffs.  Sleeping in trees protects them from lions and hyenas, but not leopards.  In daylight hours, when many large carnivores are snoozing, baboons forage in groups, paying constant attention to reality.

Spending time on the ground increased their vulnerability to daytime predators.  Male baboons evolved big, strong bodies and large canine teeth.  When predators approach, male baboons form a point defense to obstruct a quick, easy, surprise kill.  While the males hold off the threat, the females and their offspring have a chance to escape.  Baboons did not fabricate weapons and hunt animals larger than they were but, on happy days, they could mob a leopard and disassemble it.  Readers who have killed adult leopards with their teeth and bare hands know that this can be very dangerous.

The ancestors of both baboons and humans moved onto the savannah, where they learned to survive as ground dwelling primates in a rough neighborhood that included lions, hyenas, leopards, cheetahs, and crocodiles.  Baboons demonstrate that primates can survive in a dangerous habitat without spears, fire, or complex language — and they can do this without causing irreparable ecosystem degradation.  With smaller brains, grunt communication, and sticks and stones, the baboons have brilliantly lived sustainably for millions of years.  They continue to enjoy a healthy, pleasant, and traditional wild life.  Thus, our ancestors were not forced to choose between tool addiction and extinction. 

Baboons have tails, so they are monkeys, not apes.  Paul Shepard noted that ground monkeys are “the most aggressively status-conscious creatures on Earth.”  High-ranking males have primary access to females and food.  The rank order in the hierarchy regularly changed.  So, to maintain or elevate your rank, it was important to brutally attack your inferiors at every opportunity.  Daily life was a state of heightened stress and anxiety.  Any minute you might be chased, pummeled, and bitten. 

Robert Sapolsky spent 30 years studying a troop of baboons.  Over time, he came to like a few of them, but he really disliked the troop, because they were exceptionally mean to each other, hour after hour, day after day.  He came to understand that hierarchy and competition can be a destructive force in a community, and this principle also applied to humans, many of whom are shattered by stress filled lives.

Gorillas

Gorillas evolved a different mode of sustainable living.  They never left the tropical forests, and their diet is primarily vegetarian.  They would have a hard time surviving outside of the forest.  Gorillas spend hours each day stuffing their faces at the salad bar.  They have evolved large guts in order to digest this bulky fibrous feast.  Insects provide the animal food in their diet.  In one study, 25 percent of gorilla poop samples contained bits of termites.

Males can be twice as heavy as females, growing up to 485 pounds (220 kg).  The big guys can’t climb trees, but smaller gorillas do.  Trees are a place to sleep, and to escape from predators.  They live in groups of 6 to 30 individuals, dominated by one or two silverback males.  Silverbacks are generally shy and relaxed, except when disturbed by uninvited humans or other gorillas.  The only predators they fear are humans.

Gibbons

There are about 20 species of gibbons, apes that inhabit the tropical forests of Southeast Asia.  Gibbons are primarily arboreal, and they live in small monogamous groups.  They can swing through the tree canopy with astonishing speed — up to 34 miles per hour (55 km/h).  Science calls this form of travel brachiation.  Today, physically fit humans still have a limited ability to brachiate.  As a schoolboy, I used to swing by my arms, from rung to rung, on the monkey bars at the playground. 

Members of most gibbon species range in size from 12 to 17 pounds (5.5 to 7.5 kg).  Because they are small, confronting large predators is not an option, so the males and females of most species are about the same size.  Smallness is an asset, enabling them to travel rapidly through the forest canopy.

Wild Free and Happy Sample 02

[Note: This is the second sample from my rough draft of a far from finished new book, Wild Free & Happy.  I don’t plan on reviewing more books for a while.  My blog is home to reviews of 196 books, and you are very welcome to explore them.  The Search field on the right side will find words in the full contents of all rants and reviews, if you are interested in specific authors, titles, or subjects.] 

Our Tree Critter Ancestors

The dawn of life on Earth began maybe four billion years ago, with the emergence of single-celled beings, the common ancestors of all forms of life, including us.  Let’s fast forward to around 65 million years ago, when our first primate ancestors came into existence, not long after dinosaurs moved off the stage.  These critters were squirrel-sized, and lived high above the ground in the humid tropical rainforests of Mother Africa.  They were probably insectivores, furry little hunters that dined on the delicious flesh of bugs and grubs.

Arboreal (tree-dwelling) primates had little need for a powerful sense of smell like most terrestrial (ground-dwelling) animals have.  What they needed was excellent stereoscopic vision, via forward oriented eyes that provided accurate depth perception, so they could scamper and leap through the branches without mishap.  Being able to perceive colors made it easier to find ripe fruit, which was a primary food source.  Even today, bright red objects attract our attention.

Their hands and feet evolved into forms fine-tuned for grasping bark, vines, and branches, with toes and fingers tipped with nails, not claws.  Fingers were long and curved, wrists freely rotated, and shoulder joints were flexible.  An acute sense of touch and a sharp mind helped them excel at airborne acrobatics.  Humans retain a number of these arboreal traits.

Our ancestors were tree-dwellers for most of the 65 million year saga of primates.  A look in the mirror shows clear evidence of this heritage.  Most primate species today remain partly arboreal.  Humans are the only living primates that are fully terrestrial.  Large male gorillas do not sleep in the trees, but the other gorillas do.

In the rainforest, food was available year round, so our ancestors enjoyed an easy life.  Living amidst a cornucopia of organic fruit, nuts, insects, and assorted tree critters, they could live happily without tools, fire, cooking, cell phones, or psych meds.  The climate was comfortable, so there was no need for clothing.  A simple tree nest was all they needed.  It was a wonderful way of life, while it lasted.  They only used renewable resources, and they left no permanent scars on the forest.  Like all other animals at the time, they had a way of life that was genuinely sustainable.

Shift to the Savannah

Climate change is a trickster that takes great delight in periodically pulling the rug out from under stable ecosystems, and watching them scramble to survive.  It’s an exciting roller coaster of hot and cold, wet and dry, calm and stormy.  Species that can’t adapt to changing conditions go extinct, creating opportunities for other species to fill their ecological niche.  The show of life must go on.

Long, long ago, in Mother Africa, the climate was warm and moist, home to the magnificent rainforests in which primates evolved.  Later, around five million years ago, as glaciers grew in the Northern Hemisphere, the climate in African rainforests began to shift to cooler and dryer.  By two million years ago, lush rainforests were far smaller, largely replaced by expanding savannahs (grasslands with scattered trees).  If it wasn’t for climate change, you might be sitting naked on a branch today, wild, free, and happy in a lush rainforest paradise, nibbling on fruit with your friends and family, in a clean, healthy, sustainable world.

As the rainforests shrank, our tree-dwelling ancestors were something like tadpoles in a puddle that was drying up.  Many species of arboreal critters went extinct, but not all of them.  The ancestors of chimps, bonobos, gibbons, and orangutans were able to remain in the forest and avoid extinction, while baboons, gorillas, and our ancestors took a deep breath, moved to the ground, and tried to adapt to a new way of life.

On the savannah, our early ancestors were weird looking, funny smelling undocumented immigrants, attempting to survive in a habitat for which evolution had done little to assist them.  Their limited speed, size, and strength were serious drawbacks.  They were newcomers in a grassland neighborhood where most of the long-term residents had been coevolving for millions of years.  The new neighborhood included numerous large carnivores that were strong, fast, and equipped with sharp claws and fangs.  They specialized in weeding out the injured, sick, elderly, immature, and inattentive.  Many of our ancestors became organic cat food.

To survive, our ancestors used several defensive strategies.  They lived in groups, where many eyes were constantly paying attention to the surroundings.  When someone noticed a threat, loud calls were made to alert the gang, and the predator lost the advantage of surprise.  Sometimes they mobbed hungry predators, aggressively assaulting them.  Other times they quickly scattered in every direction.  The ancestors were careful to be as invisible as possible.  They chose sleeping places that offered the most security.  As a result of their cleverness, luck, and risky choices, an enormous number of ground-dwelling primates survive today.

Rainforests have high biodiversity, they provide a pleasant home for huge numbers of species.  Savannahs support far less biodiversity but, unlike dense forests, they provide excellent habitat for many large animal species.  A square mile of rainforest contains tons of biomass in its trees, far more than a square mile of grassland, but grassland can produce more new biomass every year, primarily during the wet season.  This nutritious vegetation, which includes high-energy seeds, grows close to the ground, a convenient location for grazing animals. 

The biological productivity of grasslands (savannahs, prairies, and steppes) encouraged the emergence of large herds of herbivores and their predators.  When our ancestors moved to the ground, evolution had not equipped them for hunting large game, or escaping from speedy carnivores.  They had two options, adapt or go extinct.