# Are Passenger Pigeon populations overestimated? **URL:** \ **Category:** Factual Questions\ **Created:** [August 31, 2014, 11:37pm UTC](https://boards.straightdope.com/t/are-passenger-pigeon-populations-overestimated/697091 "2014-08-31T23:37:40Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Amateur\_Barbarian](https://avatars.discourse-cdn.com/v4/letter/a/59ef9b/32.png) [@Amateur\_Barbarian](https://boards.straightdope.com/u/Amateur_Barbarian)\ **Post date:** [August 31, 2014, 11:37pm UTC](https://boards.straightdope.com/t/are-passenger-pigeon-populations-overestimated/697091/1 "2014-08-31T23:37:40Z")
There’s been a lot in the news/feature stuff lately about Passenger Pigeons, since it’s 100 years since the last one died. I have always been a bit skeptical of the descriptions of their population, given how 1750-1900 natural scientists had a tendency towards hyperbole, excessive extrapolation and just plain misunderstanding. So, okay: in 1800 there were a hell of a lot of Passenger Pigeons. By 1900 they were rare; by 1914 they were gone. But were there really flocks of 2-3 billion that could darken the sky for days as they passed, and roosting flocks of a million, and so forth? That just seems so excessive for North American ecological conditions, and that there’s no other species with a tenth that many specimens, even before human predation and so forth. What could flocks that size possibly live on, even in a largely pre-human ecology? Especially with their fragile, 1-egg-per-year mating cycle? So were PPs really that incredibly numerous, or were 19th century observers… mistaken? ---
**Author:** ![Little\_Pig](https://avatars.discourse-cdn.com/v4/letter/l/c57346/32.png) [@Little\_Pig](https://boards.straightdope.com/u/Little_Pig)\ **Post date:** [August 31, 2014, 11:40pm UTC](https://boards.straightdope.com/t/are-passenger-pigeon-populations-overestimated/697091/2 "2014-08-31T23:40:16Z")
Appears their numbers were not exaggerated. Interestingly, there may have been [more than one reason](http://www.newyorker.com/tech/elements/century-extinction)for their extinction. ---
**Author:** ![jtur88](https://avatars.discourse-cdn.com/v4/letter/j/e9c0ed/32.png) [@jtur88](https://boards.straightdope.com/u/jtur88)\ **Post date:** [August 31, 2014, 11:50pm UTC](https://boards.straightdope.com/t/are-passenger-pigeon-populations-overestimated/697091/3 "2014-08-31T23:50:07Z")
Trained crowd control experts can’t even estimate within 50% the size of a crowd of protesting or demonstrating human beings while they are standing there looking at them. There isn’t even any agreement about what is the most abundant species of bird in North America today, much less a reliable population estimate. ---
**Author:** ![jtur88](https://avatars.discourse-cdn.com/v4/letter/j/e9c0ed/32.png) [@jtur88](https://boards.straightdope.com/u/jtur88)\ **Post date:** [September 1, 2014, 12:06am UTC](https://boards.straightdope.com/t/are-passenger-pigeon-populations-overestimated/697091/4 "2014-09-01T00:06:58Z")
There are estimates as high as ten billion for the present day population of the Red-billed Quelea of Africa, but their population is probably highly variable from year to year according to feeding conditions and survival rates. There is no sign that they are declining in numbers, despite diligent efforts to destroy them. Over 150-million have been killed in a year, with no visible effect on their numbers. Given that, it is entirely possible that the Passenger Pigeon population was even more than 2-3 billion. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [September 1, 2014, 12:16am UTC](https://boards.straightdope.com/t/are-passenger-pigeon-populations-overestimated/697091/5 "2014-09-01T00:16:55Z")
> [@Amateur\_Barbarian](#): > > What could flocks that size possibly live on, even in a largely pre-human ecology? The Passenger Pigeon may have specialized on exploiting the nut crops of [mast-seeding](http://en.wikipedia.org/wiki/Mast_(botany)) trees such as acorns, beeches, and chestnut. Such trees fruit heavily only at an interval of several years, when they produce a very large crop all at once, probably in order to satiate nut-feeding animals so the entire crop won’t be eaten. Passenger Pigeons didn’t breed in the same areas from one year to another. Instead the vast flocks would move to areas where there was a mast crop that year. Back when most of eastern North America was covered with forest consisting of a large proportion of nut-bearing trees, especially the now nearly extinct American Chestnut, that was a more feasible strategy. Once most of the forest had been removed, that was no longer viable. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [September 1, 2014, 12:23am UTC](https://boards.straightdope.com/t/are-passenger-pigeon-populations-overestimated/697091/6 "2014-09-01T00:23:26Z")
A new book, [A Feathered River Across the Sky: The Passenger Pigeon’s Flight to Extinction by Joel Greenberg](http://www.amazon.com/Feathered-River-Across-Sky-Extinction/dp/1620405369/ref=sr_1_1?s=books&ie=UTF8&qid=1409530729&sr=1-1&keywords=passenger+pigeon) has been reviewed favorably, though I haven’t read it. AFAIK, he confirms billions in flocks. ---
**Author:** ![BrotherCadfael](https://avatars.discourse-cdn.com/v4/letter/b/977dab/32.png) [@BrotherCadfael](https://boards.straightdope.com/u/BrotherCadfael)\ **Post date:** [September 1, 2014, 2:40am UTC](https://boards.straightdope.com/t/are-passenger-pigeon-populations-overestimated/697091/7 "2014-09-01T02:40:55Z")
> [@jtur88](#): > > Trained crowd control experts can’t even estimate within 50% the size of a crowd of protesting or demonstrating human beings while they are standing there looking at them. They are actually pretty good, but often the crowd organizers refuse to accept their estimates. The Park Service has quit issuing crowd estimates because they got so much flak from the activists. ---
**Author:** ![Askance](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/askance/32/8281_2.png) [@Askance](https://boards.straightdope.com/u/Askance)\ **Post date:** [September 1, 2014, 2:54am UTC](https://boards.straightdope.com/t/are-passenger-pigeon-populations-overestimated/697091/8 "2014-09-01T02:54:20Z")
> [@Colibri](#): > > The Passenger Pigeon may have specialized on exploiting the nut crops of [mast-seeding](http://en.wikipedia.org/wiki/Mast_(botany)) trees such as acorns, beeches, and chestnut. Such trees fruit heavily only at an interval of several years, when they produce a very large crop all at once, probably in order to satiate nut-feeding animals so the entire crop won’t be eaten. Passenger Pigeons didn’t breed in the same areas from one year to another. Instead the vast flocks would move to areas where there was a mast crop that year. Back when most of eastern North America was covered with forest consisting of a large proportion of nut-bearing trees, especially the now nearly extinct American Chestnut, that was a more feasible strategy. Once most of the forest had been removed, that was no longer viable. And one of the reasons this happened was the destruction of Amerind society, from disease, war and relocation. Their removal from the scene (often decades before full European settlement in any given area) meant that trees like chestnuts, previously kept in reasonable numbers as a crop by the locals, exploded in the years of initial European settlement and the bird numbers exploded along with them. The forests of chestnuts and billion-bird flocks were an unnatural result of the removal of the peoples who had been tending and harvesting the trees for thousands if years beforehand. ---
**Author:** ![Askance](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/askance/32/8281_2.png) [@Askance](https://boards.straightdope.com/u/Askance)\ **Post date:** [September 1, 2014, 3:03am UTC](https://boards.straightdope.com/t/are-passenger-pigeon-populations-overestimated/697091/9 "2014-09-01T03:03:58Z")
… which was itself an unnatural situation, of course … ---
**Author:** ![Revtim](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/revtim/32/1042_2.png) [@Revtim](https://boards.straightdope.com/u/Revtim)\ **Post date:** [September 1, 2014, 3:05am UTC](https://boards.straightdope.com/t/are-passenger-pigeon-populations-overestimated/697091/10 "2014-09-01T03:05:56Z")
I’m skeptical of the “darken the skies for days” claims. Is there documented evidence of this, like outdoor events being cancelled on account of pigeon eclipse? Not to mention the foot high layer of slippery birdshit… ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [September 1, 2014, 3:11am UTC](https://boards.straightdope.com/t/are-passenger-pigeon-populations-overestimated/697091/11 "2014-09-01T03:11:06Z")
> [@Colibri](#): > > The Passenger Pigeon may have specialized on exploiting the nut crops of [mast-seeding](http://en.wikipedia.org/wiki/Mast_(botany)) trees such as acorns, beeches, and chestnut. Such trees fruit heavily only at an interval of several years, when they produce a very large crop all at once, probably in order to satiate nut-feeding animals so the entire crop won’t be eaten. Passenger Pigeons didn’t breed in the same areas from one year to another. Instead the vast flocks would move to areas where there was a mast crop that year. Back when most of eastern North America was covered with forest consisting of a large proportion of nut-bearing trees, especially the now nearly extinct American Chestnut, that was a more feasible strategy. Once most of the forest had been removed, that was no longer viable. It would have to be something other than just hunting. I’ve seen flocks of some kind of bird in my state that are 1/8 to 1/4 mile wide and take 30 minutes to fly over. I can’t imagine putting a dent in such a flock. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [September 1, 2014, 3:28am UTC](https://boards.straightdope.com/t/are-passenger-pigeon-populations-overestimated/697091/12 "2014-09-01T03:28:45Z")
> [@Revtim](#): > > I’m skeptical of the “darken the skies for days” claims. Is there documented evidence of this, like outdoor events being cancelled on account of pigeon eclipse? Not to mention the foot high layer of slippery birdshit… There is also - what are the odds - a new book on the subject by Mark Avery. A [review of the book](http://www.telegraph.co.uk/culture/books/bookreviews/10987716/A-Message-from-Martha-by-Mark-Avery-review-too-much-padding.html) says: > [@](#): > > Trees collapsed under the weight of nesting birds, and the ground beneath was covered in droppings which piled up several feet deep. > > Avery calculates the overall population in the years of plenty at between five and 10 billion birds. The numbers defy belief and comprehension. As he rightly comments: “Our imaginations cannot cope.” Here’s yet another book, by [Jerry Sullivan](http://www.press.uchicago.edu/Misc/Chicago/779939pass.html): > [@](#): > > And the trees. The birds roost in piles, one atop the other, weighing down limbs so heavily that they snap. The dung rains down, burying the trunks in tons of droppings. When the flock leaves in spring, the roost is mostly dead trees. They all seem to be relying upon the many contemporary accounts, such as this one from John James Audubon, surely a reputable witness: > [@](#): > > As I traveled on, the air was literally filled with pigeons. The light of noon-day was obscured as by an eclipse, and the continued buzz of wings had a tendency to lull my senses. Before sunset I reached Louisville, Kentucky. The pigeons passed in undiminished number, and continued to do so for three days in succession. The people were all in arms. The banks of the Ohio were crowded with men and boys, incessantly shooting at the pilgrims, which flew lower as they passed over the river. Multitudes were thus destroyed. For a week or more, the population fed on no flesh other that of pigeons, and talked of nothing but pigeons. You’d think that several major books on the subject would be able to debunk the stories if they were all exaggerated. Instead, they agree that the numbers were extraordinarily huge. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [September 1, 2014, 3:40am UTC](https://boards.straightdope.com/t/are-passenger-pigeon-populations-overestimated/697091/13 "2014-09-01T03:40:28Z")
> [@Magiver](#): > > It would have to be something other than just hunting. I’ve seen flocks of some kind of bird in my state that are 1/8 to 1/4 mile wide and take 30 minutes to fly over. I can’t imagine putting a dent in such a flock. It wasn’t just hunting per se, it was disruption of the breeding colonies. As some of the accounts quoted say, when the pigeons established a breeding colony market hunters would descend upon it, and kill birds literally by millions. They would salt the carcasses in barrels and ship them to markets in the East. Aside from just killing the breeding birds, nesting by the others would be disrupted. ---
**Author:** ![Claverhouse](https://avatars.discourse-cdn.com/v4/letter/c/13edae/32.png) [@Claverhouse](https://boards.straightdope.com/u/Claverhouse)\ **Post date:** [September 1, 2014, 4:01am UTC](https://boards.straightdope.com/t/are-passenger-pigeon-populations-overestimated/697091/14 "2014-09-01T04:01:09Z")
So why didn’t the hawk population explode also ? ---
**Author:** ![Sigene](https://avatars.discourse-cdn.com/v4/letter/s/df788c/32.png) [@Sigene](https://boards.straightdope.com/u/Sigene)\ **Post date:** [September 1, 2014, 4:04am UTC](https://boards.straightdope.com/t/are-passenger-pigeon-populations-overestimated/697091/15 "2014-09-01T04:04:44Z")
> [@jtur88](#): > > There isn’t even any agreement about what is the most abundant species of bird in North America today, much less a reliable population estimate. Not to hijack this too much, but wouldn’t it clearly be the chicken? ---
**Author:** ![Ulfreida](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ulfreida/32/8014_2.png) [@Ulfreida](https://boards.straightdope.com/u/Ulfreida)\ **Post date:** [September 1, 2014, 4:08am UTC](https://boards.straightdope.com/t/are-passenger-pigeon-populations-overestimated/697091/16 "2014-09-01T04:08:25Z")
> [@Askance](#): > > And one of the reasons this happened was the destruction of Amerind society, from disease, war and relocation. Their removal from the scene (often decades before full European settlement in any given area) meant that trees like chestnuts, previously kept in reasonable numbers as a crop by the locals, exploded in the years of initial European settlement and the bird numbers exploded along with them. > > The forests of chestnuts and billion-bird flocks were an unnatural result of the removal of the peoples who had been tending and harvesting the trees for thousands if years beforehand. Cite, please, I would like to read more about this. ---
**Author:** ![beowulff](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beowulff/32/542_2.png) [@beowulff](https://boards.straightdope.com/u/beowulff)\ **Post date:** [September 1, 2014, 4:11am UTC](https://boards.straightdope.com/t/are-passenger-pigeon-populations-overestimated/697091/17 "2014-09-01T04:11:57Z")
> [@jtur88](#): > > Trained crowd control experts can’t even estimate within 50% the size of a crowd of protesting or demonstrating human beings while they are standing there looking at them. How would you know? ---
**Author:** ![Magiver](https://avatars.discourse-cdn.com/v4/letter/m/4491bb/32.png) [@Magiver](https://boards.straightdope.com/u/Magiver)\ **Post date:** [September 1, 2014, 4:18am UTC](https://boards.straightdope.com/t/are-passenger-pigeon-populations-overestimated/697091/18 "2014-09-01T04:18:56Z")
> [@Colibri](#): > > It wasn’t just hunting per se, it was disruption of the breeding colonies. As some of the accounts quoted say, when the pigeons established a breeding colony market hunters would descend upon it, and kill birds literally by millions. They would salt the carcasses in barrels and ship them to markets in the East. Aside from just killing the breeding birds, nesting by the others would be disrupted. I agree with your assessment. I’m kind of surprised people of the day didn’t grok what the common denominator was that drew the birds in. Taking into account the lack of scientific standards in the 19th century I would think the average person was better adept at identifying trees and such since there was a greater reliance on local resources. I’m surprised we don’t have multiple observations on what the birds associated themselves with in terms of habitat. I wish I could have seen them in such large numbers. The few times I’ve seen large flocks passing by I’ve taken the time to stop and take in the event. It’s really cool seeing/hearing the ebb and flow of thousands of birds going by. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [September 1, 2014, 4:40am UTC](https://boards.straightdope.com/t/are-passenger-pigeon-populations-overestimated/697091/19 "2014-09-01T04:40:06Z")
> [@Claverhouse](#): > > So why didn’t the hawk population explode also ? How do we know it didn’t? In fact, the nesting colonies attracted many predators including birds of prey. Cooper’s Hawks were supposed to follow the migrating pigeons. However, because the flocks were so mobile the local predators would only have a single season to build up its population before the birds moved elsewhere. ---
**Author:** ![jtur88](https://avatars.discourse-cdn.com/v4/letter/j/e9c0ed/32.png) [@jtur88](https://boards.straightdope.com/u/jtur88)\ **Post date:** [September 1, 2014, 5:12am UTC](https://boards.straightdope.com/t/are-passenger-pigeon-populations-overestimated/697091/20 "2014-09-01T05:12:35Z")
> [@Sigene](#): > > Not to hijack this too much, but wouldn’t it clearly be the chicken? Obviously talking about birds in the natural environment whose populations are not controlled to meet human needs. I haven’t heard of any ball games being postponed by darkness, from a bunch of chickens flying over. [Next page](https://boards.straightdope.com/t/are-passenger-pigeon-populations-overestimated/697091.md?page=2)