Human Impact on Bird Populations
Only dinosaurs can be extinct. At least, that’s what I thought when I was younger. Whenever I heard the word “extinct,” it was used to describe creatures that far predated humans.
It never occurred to me that entire species of animals have died out over the course of human history, and it especially didn’t occur to me that entire species of animals have died out because of humans throughout history. When I was five years old, I read a book called “I Wonder Why the Dodo is Dead.” This book taught me about an extinct animal called the dodo bird. The dodo bird was not a dinosaur, and it lived less than four hundred years ago, well after the dawn of humanity. This was a challenging concept for young me. My understanding of the word “extinct” began to shift.
As I read more about the dodo, another shocking fact was revealed. The dodo bird went extinct because of people. As I grew older, I became more aware of the devastating impact the human race has had on the populations of many different animals. I came to realize that extinction is not a thing of the past. Species die out every day.
Bird species, in particular, have been greatly affected by human activity. Humans have caused the extinction of many different species of birds in the last several hundred years. In order to understand the impact that humans have had on bird populations, we will examine the specific causes of extinction for four different bird species that have disappeared since the sixteenth century. We will look at the demise of the dodo bird, the great auk, the passenger pigeon, and the po’o-uli. We will then examine the long term effects of bird extinction on the ecosystem. Before the sixteenth century, the dodo bird lived on the island of Mauritius with no natural predators (“Dodo Bird: an Extinct Species”).
In 1505, the Portuguese discovered the island, and it quickly became a common stop for ships that were involved in the spice trade (“Dodo Bird: an Extinct Species”). Though the Portuguese had discovered the home of the dodo bird, its existence would not be documented for nearly a century. The dodo bird was first described in Dutch explorer Wybrand Van Warwijck’s journal in 1598 (“History of the Dodo Bird”). How the bird came to be called a dodo is unclear, as Warwijck referred to it as a “walgyogel” (“History of the Dodo Bird”). Some believe it came from the Dutch word “dodoaars,” which describes a knot of feather, while others point to the Portuguese word “dodo,” which means fool (“History of the Dodo Bird”).
In the next 100 years, the Dutch set up penal colonies on Mauritius and introduced non-native species including pigs, rats, and monkeys to the island (“Dodo Bird: an Extinct Species”). Having evolved with no defense mechanisms to protect against predators, the dodo bird was an easy food source for Dutch colonists and the animals they introduced to the ecosystem. Overhunting and non-indigenous diseases decimated the dodo population, and in 1681, the last dodo bird was killed (“Dodo Bird: an Extinct Species”). The dodo bird was just one of many species to be extinguished by humans. While the last dodos were disappearing from Mauritius, another bird species was facing a similar struggle for survival on the European Atlantic coast.
The great auk was a large flightless bird built for swimming. It was clumsy on land, and easy to kill (Rabadi). The great auk was a valuable bird, used for oil, meat, and feathers (Rabadi). Hunting the great auk was a lucrative business, and by the mid 1500’s, the bird’s population was rapidly declining (“The Extinction of the Great Auk”). By 1794, the great auk had become quite rare, and the British government attempted to intervene. A law was made to ban the killing of the great auk for its feathers (“The Extinction of the Great Auk”).
This attempt to save the great auk came too late, though. The law did little to stop the killing, and the bird’s increasing rarity only served to make it more valuable. In 1840, one of the few remaining great auks was captured by three Scottish sailors on a sea stack called Stac-An-Armin (Galasso). On the journey home, the sailors ran across a terrible storm. The superstitious men blamed the storm on the great auk, and four days after its abduction, the bird was stoned to death for witchcraft (Galasso).
A great auk would never again be seen on the British Isles. The last pair of great auks lived on Eldey Island, off the coast of Iceland (Galasso). On July 3, 1844, Jon Brandsson, Sigurour Isleifsson, and Ketill Ketilsson, having been employed by a merchant, arrived on Eldey to capture the birds (“The Extinction of the Great Auk”). The great auks were caught and strangled, and in the commotion, Ketilsson stepped on the egg the pair was incubating, wiping out the species forever (“The Extinction of the Great Auk”). The actions of humans can eradicate even the most abundant bird species on the planet.
We learned this lesson with the extinction of the passenger pigeon. In 1833, famous naturalist John James Audubon described the passenger pigeon as the most numerous bird in North America (Biello). With an estimated population of over three billion, it’s likely that they were the most numerous birds not only in North America, but in the world (Biello). It took less than a century for the passenger pigeon’s population to plummet from three billion to zero. Like so many other species, the passenger pigeon was a victim of excessive hunting.
The passenger pigeon was a common source of meat in nineteenth century America, and its large flocks made it an easy target for commercial hunting. In 1850, thousands of people were working in the passenger pigeon industry (“Passenger Pigeon: an Extinct Species”). Killing for commercial purposes was increased by railroads, which made it possible to transport fresh meat across the country (“Passenger Pigeon: an Extinct Species”). The pigeons were slaughtered at an impressive rate. It is recorded that in 1855, one New York plant was processing eighteen thousand pigeons every day (“Passenger Pigeon: an Extinct Species”).
The pigeon population also suffered due to loss of habitat. European settlers destroyed many of North America’s forests in the 19th century, robbing the passenger pigeons of their home and their breeding grounds (Biello). In 1880, the remaining passenger pigeons were spread across the country in flocks too small to stimulate breeding behaviors or compete with other species for nesting grounds (“Passenger Pigeon: an Extinct Species”). The passenger pigeon was not able to recover from their massive dip in population, and by 1900, they could no longer be found in the wild (“Passenger Pigeon: an Extinct Species”). The last known passenger pigeon, a female named Martha, was kept at the Cincinnati Zoo (“Billions to None.
.. the Extinction of the Passenger Pigeon”). On the first of September in 1914, Martha died (“Billions to None..
. the Extinction of the Passenger Pigeon”). Martha’s body was skinned and mounted. It now sits in the archives of the Smithsonian Institute in Washington, D. C. (“Martha, a Passenger Pigeon”).
Though humans have made great strides in the field of conservation, we are still causing species to disappear in the modern era. The po’o-uli, or black-faced honeycreeper, is a bird that lives on the island of Maui. Though there are no known living birds of this species, it is not technically extinct. The po’o-uli is classified as critically endangered, because the last sighting was recent enough that scientists can’t be sure that they’ve been completely wiped out (“Po’o-uli or Black-faced Honeycreeper”). University students discovered the po’o-uli in 1973 (“Po’o-uli or Black-faced Honeycreeper”).
At the time, there were 76 birds per kilometer (“Po’o-uli or Black-faced Honeycreeper”. The po’o-uli population was on the decline due to loss of food sources and habitat through deforestation, and the introduction of non-native predators by humans (“Po’o-uli or Black-faced Honeycreeper”). The po’o-uli became prey for pigs, rats, and cats. In 1981, there were 15 po’o-uli per kilometer (“Po’o-uli or Black-faced Honeycreeper”). In 1985, there were 8 po’o-uli per kilometer (“Po’o-uli or Black-faced Honeycreeper”). In 1997, there were only 3 known members of the species in existence (“Po’o-uli or Black-faced Honeycreeper”).
In September of 2004, one of the three birds was captured by biologists in an attempt to save the species. He died on November 26, 2004, before biologists could find him a mate (“Po’o-uli or Black-faced Honeycreeper”). The two remaining birds have not been seen since 2004 (“Po’o-uli or Black-faced Honeycreeper”). The po’o-uli is likely extinct, but it will not be listed as such until the extinction is proved beyond reasonable doubt. Birds are an important part of the natural world, and the disappearance of any bird species has the potential to disrupt the ecosystem.
Birds play large roles in pollination and seed dispersal for most trees (“Birds’ Role in Ecosystems”). If birds continue to go extinct at such an alarming rate, tree populations will suffer. Without birds to carry seeds from place to place, new trees will not be able to grow. Without birds to assist in pollination, trees will not be able to produce fruit. Bird extinction has major consequences on forest regeneration, and this is a problem that affects humans directly (“Birds’ Role in Ecosystems”).
Forests provide humans with countless natural resources. Forests are a source of food, lumber, and medicine. Forests help prevent erosion and natural disasters like flooding. Forests create oxygen for people to breathe. Humans rely on forests for survival. Forests could not exist without birds.
Extinction is not a thing of the past. Extinction is our present. Through overhunting, destruction of habitats, and the introduction of non-indigenous predators to new regions,humans have caused the extinction of the dodo bird, the great auk, the passenger pigeon, the po’o-uli, and many more. Since 1500, 136 bird species have gone extinct, and 14 bird species that are likely extinct have been classified as critically endangered (“Data Zone”). Humans have stamped many creatures out of existence, but they also have the power to stop the destruction. We humans need to start considering the consequences of our actions before we lose another irreplaceable species.
It’s time to rally behind the goal of conservation. It’s not too late to keep the birds we have left from going the way of the dodo.