What happened to the passenger pigeon? Numbering up to 5 billion individuals, it was once the most abundant bird in North America — and possibly, the world.
For about 15,000 years, passenger pigeons coexisted with Native Americans in the forests that once blanketed the eastern side of the US. The tribes respected the passenger pigeon as a sacred being. It was hunted for food, but sustainable practices were carefully followed.
When European colonists arrived on the continent, they viewed and interacted with the bird in a completely different manner. It was considered bad luck to encounter large flocks of passenger pigeons — some even believed that the event would be followed by illness. Nests were raided, trees burned and cut down, and thousands of pigeons shot from the sky in one sitting.
Before anyone realized it, it was too late; there was a sharp decline in the passenger pigeon population.
Habitat
Passenger pigeons were most prevalent in the deciduous forests of North America, including near the Rocky Mountains and the Great Plains. Breeding took place most prominently near the Great Lakes. During winter, the birds spread across some of the warmer southern states, such as North Carolina, Texas, and northern Florida.
Tens of thousands of passenger pigeons would congregate; these massive groups were referred to as cities. Studies suggest the sheer volume of the birds caused an evolutionary response from the trees and vegetation in their habitat. In fact, the bird’s impact was so strong that some ecologists acknowledge it as a keystone species.
For instance, red oaks evolved larger seeds, too big for passenger pigeons to swallow. On the other hand, white oaks adapted an unusual masting cycle, beginning in fall — when there were fewer passenger pigeons around. This resulted in white oaks becoming the dominant tree species in these areas.
As you can imagine, tons of birds = tons of poop. In areas where cities stayed for an extended time (i.e., for roosting), their excrement killed some of the vegetation below. Although this sounds like a problem, it actually provided the soil with rich nutrients to grow stronger plant life in the future.
Native Americans and Passenger Pigeons
Although hunting policies varied between tribes, one rule was almost unanimous: hunting could not take place during nesting. Instead, nests served as a chance to observe and better understand the bird. This allowed the pigeons the time they needed to parent their young until they were strong enough to survive on their own.
The Seneca believe that the Council of Birds designated passenger pigeons as a food source for the tribe. Before hunting, nesting sites were monitored and managed to ensure the birds’ needs were met first. They showed gratitude for the bird’s offering by creating a pigeon dance. The dance was performed to open their annual Maple Festival.
Both the Cherokee and the Neutrals believe(d) that the bird was a guide that saved the tribes from starvation. During the Cherokees’ Green Corn Ceremony, they performed a dance conveying a pigeon hawk chasing a pigeon.
For the Ho Chunks, passenger pigeons were only hunted when the Chief planned a feast. A pigeon feast was also held by the Wyandot tribe every 12 years, known as the Feast of the Dead. It was believed that during the ceremony, the souls of the dead changed into passenger pigeons which were then consumed by the tribe.
It’s clear that these hunting regulations, paired with respect for the bird, allowed passenger pigeons to thrive — that is, before European influence. In addition, Native Americans practiced prescribed fire and maintained trees bearing more fruits and nuts. These were the bird’s primary food source. So its healthy population during these times was likely influenced by the Native Americans.
Features
For several years, it was believed that passenger pigeons’ closest relative was the mourning dove. The two birds have almost identical plumage, after all. But after genetic analysis, scientists realized it was closer to the family of New World pigeons, such as the band-tailed pigeon.
They had had black bills, and their eyes and feet were both red. However, males were particularly striking in appearance with bright red-orange chests and blue-grey heads. Black spots speckled across their wings, and their necks shined in iridescent bronze. Females were less vibrant in color, with brown, grey, and white gradients throughout their plumage.
This bird was built for aerodynamics. Its head and neck were small, while its body was long and narrow, as were its wings. Passenger pigeons were also equipped with extra-large breast muscles, allowing for extended periods of flight. With such a build, they were capable of flying up to 62 mph!
Diet
Passenger pigeons ate a diet comprising whatever mast was available during the season. Fall brought plenty of acorns, beechnuts, and chestnuts. In springtime, they turned to various berries and invertebrates to keep their bellies full. In addition, agriculture introduced the birds to cultivated grains, such as buckwheat. They also showed a fondness for salt, as they were seen consuming salt from soil or brackish springs.
The birds had a unique physical feature — a super elastic mouth and throat (known as a crop). This allowed them to swallow whole acorns at once and store large amounts of food to snack on later. With a crop expanding as large as a softball, the bird could stash up to 17 acorns at once!
Behaviour
When groups of passenger pigeons migrated, it blackened the sky. This phenomenal behaviour is what gave the bird its name. It originates from the French term, pigeon de passage — passage, meaning to pass by (swiftly).
Migration took place as the birds searched for food, shelter, and breeding sites. Communal roosting and breeding were practiced, and it was common to see over 100 nests in a tree. In 1871, it was estimated that 136 million passenger pigeons nested within 850 square miles in Wisconsin.
Most pigeons give their courtship display on the ground with struts and bows. However, on the ground, passenger pigeons were a bit awkward. Instead, males hung from branches, flapping their wings while angling their heads over the female's neck. Once she accepted his advances, they would preen each other and clasp beaks to signal that the deal was sealed.
Passenger pigeons were vocal birds. They croaked while building their nests and made bell-like calls while mating. Now, imagine how intense the volume would be with thousands of these talkative pigeons combined! Unsurprisingly, it was often described as "deafening, unmusical, and harsh."
Aside from the unfavourable noise levels, people tended to avoid trees full of passenger pigeons because they risked being hit by fallen branches. The weight of the bird masses frequently broke weak limbs, crushing anything below (including the birds themselves).
Parenting passenger pigeons teamed up to nourish their young. Both secreted a cheese-like substance from their gullets, called crop milk. This was fed to the chicks for about a week until it was time for the hatchling to find its own food sources. Wild passenger pigeons are estimated to have had a lifespan of about 15 years.
Extinction
The hunting and consumption of passenger pigeons was nothing new, but European settlers took it to another level. Pigeon meat was cheap and easy to obtain for the colonists — so the bird was hunted extensively for decades. Plus, juveniles are said to have tasted the best, making them the first target for pigeon hunters.
Additional uses for the bird included medicinal purposes, while the feathers were used for bedding. The blood, pulverized intestinal lining, and excrement were used to treat certain illnesses and ailments.
As flocks of passenger pigeons flew by, Europeans used shotguns to take them down by the thousands. Another common method was to use decoy pigeons to trick flocks into landing close enough for the hunters to capture them with nets.
Hunters would go so far as to burn and cut down trees in which passenger pigeons nested. As the tree caught fire, adult birds fled, leaving juveniles to fall into the eager hands of the hunters. It took a while for anyone to realize the detrimental effect of their mass hunting, as the birds’ population was so vast.
During the 1870s, several instances of nesting attempts were disrupted and unsuccessful. Eventually, it got so bad that the birds began abandoning their nests at the sight of approaching humans. This is about the time that the decline of the passenger pigeon started to become apparent.
At the same time, there was mass deforestation which was reducing the passenger pigeon’s habitat. This, paired with the inability to breed effectively, caused the bird population to dwindle to almost nothing by the 1890s.
The last confirmed wild bird was shot down in 1901 — at this point, the remaining passenger pigeons were captured and distributed to noblemen and zoos. Martha, the last captive individual, died in the Cincinnati Zoo in 1914.
This was labelled one of the greatest anthropogenic (human-induced) extinction cases. As senseless and avoidable as it was, it provoked interest in the conservation movement. In response, several laws and practices were enacted to prevent similar extinctions. In 2012, The Great Passenger Pigeon Comeback began in an effort to “bring the bird back,” using the DNA of its closest living relative.