Bison on the Great Plains and the Passage of the Passenger Pigeon

Ellsworth and McComb 2003
This paper is about the effects that passenger pigeons had on forests. There were an immense amount of passenger pigeons, about 3-5 billion individuals in North America. Because of these huge numbers, the flocks consumed a large amount of oak, American beech, and chestnut (among other types of plants). They damaged forests when the huge flocks roosted, and because their numbers were so vast, the excrement from the passenger pigeons was abundant enough to even kill vegetation on the forest floor. In addition, the weight of the pigeons alone was enough to break branches and destroy trees by making them fall over. Their distribution was large, covering a huge portion of North America.

Due to their feeding habits, they not only consumed a large amount of oak/chestnut/beech, but their excrement could have been somewhat responsible for oak being dominant in parts of North America due to the distribution of the oak seeds in their feces. When roosting, it was claimed that every part of a tree was covered, and that some pigeons roosted on each others' backs, adding weight to the trees and aiding in their collapse. So the density of roosts, while not known as fact, was large and the land area that they could occupy was, in turn, immense.

In addition to physical damage caused by roosting, the amount of excrement from the roosting pigeons caused the death of a lot of plants due to chemical damage. By comparing the passenger pigeons deposits to the deposits of red winged blackbirds, the authors came up with an amount of excrement that was deposited by pigeons.

Passenger pigeon damage also increased other natural damage- the weakening of branches and trees by the roosting, and the chemical damage weakening vegetation and tree roots and structure, made forests more susceptible to fires and ice storms and wind storms. Specifically, the forests were more prone to fire damage, and there was a higher frequency of fire as a result of disturbance by the pigeons. Now, since pigeons consumed oak and distributed it far, and because oaks are more fire resistant than other trees such as maple and hemlock and beech, it could have been the passenger pigeon's abundance that led to oak species being so dominant in areas in North America.

The authors looked at the effects of passenger pigeons on forests mainly, and how their impact affected them. They made them more susceptible to storms and fires, the passenger pigeon also spread fire resistant tree species like oak.


Questions:

1. If the passenger pigeon hadn't been hunted to extinction by humans, what do you think would have happened to them naturally? Would they have exhausted their food sources and environments and ended up thinning out their own numbers? Something else?
2. In addition to #1, if the passenger pigeon hadn’t gone extinct, do you think their numbers might have ended up leading to another species’ extinction?
3. Do you think the passenger pigeon really had this dramatic effect on forests? If not, what other factors could have influenced the author's data?
4. What other species (besides humans) can you think of that affect environments so greatly?


Bison Timeline

This compilation of data provides readers with a recap of a major bison extirpation event. This extreme reduction in North American bison occurred over a geological instant, a time period of only about 200 years, and was the results of both indirect and direct human influence. Beginning in the 18th century, Euro-American settlement across the country had many implications for native wildlife. Agriculture along with foreign disease and competing livestock had negative impacts for the 30-60 million bison that currently inhabited the land. They were completely wiped out of Ohio by 1802, from west of the Rocky Mountains by the 1840’s, and from Idaho by the 1860’s. This pattern of human mediated extirpation continued throughout the remainder of the 1800’s with contributing factors such as railroad construction, increasing hide trading, trading of bison carcasses, and generalized hunting for meat and/or sport. Few bills were passed in order to protect the bison, however, due to the extreme profit margin that these animals provided, these laws were neither followed nor enforced to any significant degree. In the 1870’s, slaughter of bison became a means for ridding Indians of their food source in order to gain control over them. Additionally, wealthy individuals captured or bought bison in order to start their own private herds. By 1885, there were fewer than 400 wild bison left in the US, and this massive decline was also evident in Canada.

In 1905, the American Bison Society was founded by private citizens in order to protect bison and attempt to rectify their mass destruction. Additionally, bison were donated to preserves in order to establish government herds, and a National Bison Range was established. These new installations appear to have had positive impacts on bison as their numbers began to rise again in the early 1900’s, with an estimated population of 12,521 in 1919. Additionally, sales of large proportions of live bison begin during this time period. By 1935, the bison crisis had been sufficiently rectified and the American Bison Society deems itself no longer necessary. While it is nowhere near the 30-60 million bison that initially inhabited the land, by the 1990’s the numbers are back in the hundreds of thousands (in private herds), and Native Americans began attempting to reintroduce bison to their lands.

Questions:
1.What do you think may have caused the shift from the mass destruction of public herds to the donation and of live bison to public herds?
2.Why do you think so many laws were passed in the 1800s that were either not enforced? Why were laws passed in states that no longer had bison? How might your answer relate to the first question?
3.On a global scale, which wild species come to mind when considering a current comparison to the overwhelming loss of bison, or even to the re-establishment of public bison herds in the early-mid 1900s?

Comments

  1. As a point of personal curiosity, do any of you know much about the bison that are often visible along Tramway as it curves toward the casino? In reading this bison timeline, it occurred to me I know nothing about where they come from, who owns them, etc.

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    1. The Sandia Pueblo owns this herd of bison. I'm not sure where they came from, but I think a breeding program that the Indians operate. Ted Turner also has a large herd on his ranch in the south part of the state.

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  2. Ellsworth and McComb present a compelling model for the influence of passenger pigeons on Northeastern forest composition. It is reasonable to conclude that flocks of 100 million or more could have a dramatic effect on the areas where they roost. Because white oak mast “would have been almost useless as a food source by spring” (p. 1554), and white oak being fire resistant, it is easy to envision the subsequent proliferation of white oak. If the passenger pigeon was not hunted to extinction, its habitat would have been jeopardized with deforestation. If they survived to present, they would probably be endangered.
    The large herds of bison in the central plains would have also had a profound influence on the ecosystem. The grasslands were comprised of several interspecies relationships that undoubtedly relied on bison to fill a specific niche. What foods they preferred, migratory routes they travelled, seeds and nutrients they dispersed in dung, and predators or scavengers they fed would have produced effects that rippled throughout the Great Plains. It is my opinion that, the reliance of people, in the late 19th century, to buffalo revenue is analogous to our current reliance on fossil fuel revenue. They waited to the last minute to implement policies that would remove that revenue.

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  3. Pigeons are rats of the sky. That being said, I think they would have exhausted their food sources and ended up thinning their numbers. After their numbers reach a type of equilibrium, some sort of balance would emerge within the environment. It probably would have lead to extinctions of many species but also emergence of others. A lot of invasive species have been recorded to have effects like this, but are typically controlled by human intervention.

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  4. I think species come and go with time naturally. Now whether that rate is quick or slow depends on a lot of different factors. Naturally they were already doing fine so it's hard to say that they would have died out due to loss of food unless something else happened to their supply. It is also definitely possible they could have caused other species to go extinct by exploiting and overuse of resources. Honestly I can't think of a current species that is being wiped out as rapidly as the bison herds were. Those animals were in extremely large numbers. Pre 1800's I believe their numbers were estimated at around 60 million. That is an incredibly large population size for such a large animal. Imagine the effect they would have had on grasslands and soil ecology just from them moving around! BTW those bison near tramway are owned by Sandia Casino.

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  5. With the passenger pigeon, they were in very large groups and changing up ecosystems to a great extent, even to the micro level. If they had not gone extinct when they did, I believe that they could have made a larger negative impact on the forests where they roosted for an even greater extent. With their breaking of branches and chemical damage, it would have spread over a larger range as the passenger pigeon started to acquire more resources from different sources compared to the ones they were impacting.
    I believe that once there are very few individuals left of a group of animals to take or kill, humans realize that if they want more or want to see more, they will have to start protecting what is left. Even with laws, once there were very few Bison left to even find, that was the only time where individuals minds shifted over to trying to protect them. It takes almost losing the Bison to realizing how important they are to the ecosystem.

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  6. Ellsworth and McComb 2003
    1. They would have continued to tear apart, literally, forests of the oak, beech, and chestnut. This would have resulted in the thinning of the forests and of younger forests. Since they are the cause of replanting of the seeds of these trees, they would still have their food source, but the fires, probably set by humans would have reduced the numbers of the tasty beech and chestnut, leaving the oak, which would have become their main food source. These oak forests would have been munched as they grew, which would have prevented them from getting old enough to produce seeds for the birds to replant. The bird's habitat would be in shambles and the birds would either have gone extinct or would have changed their eating habits.
    2. It might have lead to the oak, beech, and chestnut tree extinction in their habitat. Since everything is connected, and the passenger pigeon existed in such numbers, it might have become prey for a larger raptor, or it's eggs might become food for other animals, thus reducing the population somewhat. There would have been opportunities for other species to have a feast here, on the pigeons.
    3. I'm sure that the pigeons has an effect on the forests, due to their shear numbers. Other factors could have been the woody debris left after the branches broke due to major wind storms, or wild fires. Large animals moving through the forest and knocking down trees could have had the same effect as the birds in terms of knocking down the trees. The soil composition under the roosts would have also influenced the author's data.
    4. What other species (besides humans) can you think of that affect environments so greatly? Megafauna, such as elephants, giant sloths, bison, large cats, could all have had similar effects on the trees and the environment, in terms of knocking down the trees, though the amount of fecal mater under the roosts would have to be attributed to something.

    Bison Timeline
    1. I think that the American people associate bison with the American West, which was not as wild and beautiful without these magnificent animals.
    2.Why do you think so many laws were passed in the 1800s that were either not enforced? Congress wanted these lands occupied by ranchers, raising beef so the elimination of the bison and the installation of the cattle was an economic necessary. The bison were a large part of the economy at the time, and therefore profitable. This is similar our exploitation of the environment currently. Laws were put in place to assist the ranchers in keeping their available pastures available for beef cattle. There was a lot of money to be made in cattle and the ranchers had a lot of pull in politics. Still do!
    3.All megafauna and the main carnivores come to mind. These are only available now in circuses, zoos, wildlife preserves, and a very few other places.

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  7. Anytime there is a species of large volume, especially in a heard or flock type situation, there will be drastic impacts on the land or surrounding species. If the passenger pigeons had not gone extinct, it is very possible that their impact would have pushed another species into extinction. As you can see from the paper, the terrestrial life in forests was already suffering greatly and if the ground vegetation was being destroyed, it is safe to assume that the smaller ground dwelling mammals would have been negatively impacted as well.
    First of all I would just like to say that reading the Bison timeline was horribly sad. It was pretty interesting that certain states would pass protection bills for the bison, but then they would not be enforced; the reason for this that I came up with is because it is much easier to pass a bill than to find the men and resources to enforce it. Regulating any type of hunting activity can be difficult and the reason it is more successful today can be attributed to modern technology and the amount of people specifically trained for such jobs. The group of animals that comes to mind when thinking about how the bison were pushed close to extinction is the wolves. I think that our protection laws and hunting regulations have definitely gotten better since the 1800's, but I do also think we have a long way to go.

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  8. Ellsworth and McComb: The beautiful thing about nature is that it is always changing. If the passenger pigeons hadn't been hunted to extinction by humans, they would have either used up all their resources or another predator would have found them tasty. The environment can only support so much until it gives. As the pigeons changed their environment and overused it, the damage would be too much and would no longer be able to support all the birds. They would start to die, and another animal would take their spot. Humans made a lot of birds go extinct, especially the terrestrial, tasty ones.

    Bison timeline: I think after you start killing all of your food resources, more people start to realize the importance of rationing. If you kill all the bison, then that's it. You don't get to create more bison magically and disperse them throughout the land. I believe as time goes, more people realize this and try to change it. That's what I think created the shift. People realized that the abundance of bison no longer existed, so they tried to reproduce the few bison that were left in private herds and slowly reincorporate them to the public.

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  9. Ellsworth and McComb 2003
    If the passenger pigeon was not hunted to extinction, it might be likely that the pigeons would have continued to grow in number until their resources began to thin and then they likely would have found a steady population that their environment could maintain. However, because of urbanization, their habitats may have been destroyed by humans and they may not be here today because of that. I think that because of the vast numbers of passenger pigeons that they easily could have caused another species’ extinction especially another type of vegetation. I believe that Ellsworth and McComb have some solid evidence to back up this theory that the passenger pigeon did have a dramatic effect on the forests. Having such a large number of birds, there’s only so many trees that can support all of them and not be affected by the vast number which can cause damage due to weight and their excrements.

    Bison Timeline
    I believe that once the American Bison Society was founded and they began to bring to light the huge problem of bison going extinct was that everyone suddenly realized that something needed to be done and it needed to be done quick, this was what led to the shift. I also think that laws were passed but not enforced because they knew that there was an issue with the bison population getting so low but because it was so profitable that no one really wanted to stop what was happening. So many people were making good money through bison that no one really wanted to put a stop to it because it was a way to make easy and fast money. One animal that comes to mind when thinking of a current comparison is the rhino. They are going extinct very quickly and it’s because they are being hunted for their horns because they are worth a lot of money. The people hunting them don’t care that they are killing off a species, they only care about getting their horns so that they can make money.

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  10. Ellsworth and McComb
    Assuming human presence and industry, their numbers invariably would have diminished somewhat and they might have adapted to city life or they might have disperse into smaller flocks. Without knowing more about the bird's behavior and natural predators it's hard to say what might have happened in the absence of human interference, though expanding their range or separating into smaller flocks for foraging seem like reasonable conclusions. Whilst reading the paper I was actually wondering what kind of impact they were having on plants and animals and whether they had caused extirpation of some species, so I would think it to be a possibility.
    It's difficult to imagine, but given the numbers suggested in the paper, it seems quite possible. However, I did wonder whether some of their sources, particularly contemporary accounts of the habits of the bird, were exaggerated or hyperbolic. A strong bias against the bird was likelt prevalent at the time (especially given its eventual extinction), so it wouldn't be surprising to see that bias seep into accounts of them.
    As far as ecosystem engineers go, there's quite a few: beavers, elephants, large whales, and even wolves have all shown to have significant ecosystem impact.

    Bison Timeline
    The mass slaughter of bison was probably one of the first indicators how impactful hunting can be, if these large animals can go from massive herds that shook the ground to no longer being visible or available in territories where they were prevously abundant. They were an iconic animal with seemingly endless abundance and their rapid decline showed just how little it takes and how quickly a species can blink out. I would suspect many of those laws passed were in effect protest or awareness laws to bring attention to the plight of the bison and perhaps pressure other states or territories into conservation efforts.
    I would consider wolves to have a similar plight to that of the bison. Mostly extirpated from the contiguous states, their reintroduction here in New Mexico (Mexican gray wolf) and in Yellowstone (gray wolf) has led to a variety of studies that suggest they have significant impact on the ecosystem and in maintaining biodiversity.

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  11. From what I understand passenger pigeons were both hunted and lost their habitat which lead to their extinction so it wasn't only hunting that did them in. I think that the habitat changes from humans would have lead to their extinction regardless of over hunting. Passenger pigeons definetly had a great influence on forests because of their massive numbers. Any invasive species usually has a massive influence on it's environment.

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  12. Ellsworth and McComb
    If passenger pigeons were still around today I think their natural predators would have caused there population size to decrease. These pigeons may have also over indulged in food resources causing themselves to adapt to new habitats or die off. Yes, I do believe that if passenger were still around they would have caused smaller birds that depend on the same food resources to go extinct. I do think the author may have over exaggerated their point on the destruction of pigeon do I do believe they were causing harm to the trees. I think a lot of herding animals cause destruction to small plants so they might also be considered invasive to plant life in some context.

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  13. Ellsworth, and McComb (2003)
    If passenger pigeons had not been hunted to extinction for humans, I would have to think humans would’ve still played a part in their decline, due to habitat degradation because of logging, and agriculture. They may not have gone extinct, but their numbers may have drastically decline. Passenger pigeons seem to have regulated their population all on their own, because many of them seem to die because of trees falls, and weather related incidents, but I do think due to the large number of population they may have altered some vegetation that other animals forage on, because their droppings increase N, K, P, which probably created higher pH content of soil.

    Bison Timeline
    The massive destruction of bison herds were due to the expansion of pioneers westward, The decline in bison numbers were also used as a military strategy to decrease the main food supply that feed the Native Americans. Laws were not enforced because ranchers were still trying to settle in the west, some believe that the bison carried diseases which would end up killing their herd of livestock.

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  14. Ellsworth and McComb 2003
    In assuming that humans didn't hunt the pigeons to extinction, the pigeons would have had to deal with other urbanization or cutting down forests caused by humans. Due to the loss of forests and many of the trees the pigeons fed on, this may have led to loss of food resources and other vegetation resulting in their decrease in populations. Because the pigeons were abundant in large numbers, and assuming they had not gone extinct, I believe that ultimately they would be out competing other bird species for the resources. However, due to the anthropogenic effects mentioned above it is still likely the pigeons and other species would eventually go into a slow decline over time due to habitat loss. I think the pigeons did have a significant effect on the environment. The biggest reason in my opinion is their ability to disperse the seed of the oak trees making the forest in the eastern half of the United States largely oak dominant.

    Timeline of Bison in the USA
    It is really disappointing to see that the bison were being killed off at such alarming rates leading to them almost becoming extinct! The donations of bison to public herds were crucial because any measures to preserve the bison was necessary since they were in such low abundance in the United States. The laws that were passed in the 1800’s were essentially coming from a good place in efforts to try to preserve bison. I think there was a fundamental lack of education of the small amount of bison that existed and how fast they were declining that led to the laws not being enforced. If more awareness was brought about to the public and government, they may have changed the way they thought about how the laws could have been taken more seriously and enforced better, which ultimately would have lead to more buffalo being preserved. A great example of a major loss of an animal that is comparable to the bison is African elephants. These elephants are on the endangered species list and are in declining numbers. In the past and in the present time, elephants are being killed for food, trophy kills and ivory trading. There are some laws in place that are intended to protect these elephants but they are not enforced efficiently resulting in elephants declining at alarming rates

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  15. If the passenger pigeon hadn’t been hunted to extinction, I think they would have managed to successfully continue living in their environment as they had been from before. I think they would have had an impact on how much food was still available to them also considering that other birds probably ate the same food as them which meant that the food source could have been depleted some. If they were not hunted and humans had destroyed their habitat like what has been done to other animals, then they may have been affected in that way as well even though they were capable of moving around to different environments.

    After the mass destruction of bison, I think people realized that they were going to be extinct within a certain amount of time if they did not follow the laws and protect the bison as they should have. This may be why there was a sudden change from the killings to having them on preserves because they were such a significant animal for many reasons and people finally thought they should be saved. As laws were passed and not enforced, I think many people didn’t believe or see the actual effects that were taking place with these bison so the laws were not going to be followed anyway. Once they realized how much damage was being done, they would take it into more consideration.

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  16. Passenger Pigeon
    1. I think every species has a limit to how large their population size gets, and will grow exponentially until they reach the upper limit to which their ecosystem can maintain. I think even if the passenger pigeon hadn’t been hunted to extinction by humans, their numbers still would have decreased upon human arrival because we would have impacted their ecosystems by deforesting areas they lived in.
    2. I think that as the population of the passenger pigeon grew, there is very good possibility that it caused another species extinction. However, once the population of the passenger pigeon reached its large size, I do not think it caused any further extinctions. I think it had become well adapted to its surroundings and its surroundings to it.
    3. I believe that the passenger pigeon had dramatic effects on the forest simply because of the sheer number of them. I think that any species when they grow to have a large population size can have dramatic effects on their surrounding environments during the expansion phase of their population growth.

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  17. Ellsworth and McComb 2003
    All species have a population density maximum, and after reaching this limit passenger pigeons would have been forced to decrease in number due to limitations in resources. Eventually the pigeons would use up their available resources, though that may take a long time. At this point the pigeons would reduce in number until their population could be supported by resources available. Over the course of the passenger pigeon’s existence, it may have caused the extinction of various species. However, they also enabled the growth of other species, such as moderately shade-tolerant species that would have benefitted from the increased light due to physical damage from roosts. I do believe the passenger pigeon could have had significant impacts on forests, but the authors are careful not to try to quantify too much the impact passenger pigeons had. They state the pigeon’s impacts are difficult to fully elucidate given current data, but that there are certain pathways they are convinced were historically influenced by the pigeons.

    Bison Timeline
    I believe the shift from the exploitation of bison to the preservation of bison came with awareness and appreciation of the animal’s vulnerable status. However, it also seems that the demand for bison would have decreased around the time of this shift due to the increased prevalence of cattle in the livestock industry. As demand for hides and meat shifted from bison to cattle, it likely would have been easier for investors to decrease the slaughter of bison and instead focus on other aspects such as their cultural significance. There were attempts in the 1800s to slow down the extirpation of bison, but they were eventually unsuccessful, I believe, due to the significant financial profit which could be made from the animals. When weighing priorities, the financial gain to be made killing bison was deemed more important than the conservation of the species. Wolves come to mind when I try to think of a comparable species. They were, and currently are, eliminated for different reasons that bison, but they hold a similar traditional role in native culture and are being actively re-introduced in several regions. Hopefully, their populations will be stable and strong one day as bison are currently.

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  18. Questions:
    1. If the passenger pigeon hadn't been hunted to extinction by humans, what do you think would have happened to them naturally? Would they have exhausted their food sources and environments and ended up thinning out their own numbers? Something else?
    If the passenger pigeon hadn’t been hunted by humans into extinction, I think that their species numbers would have eventually hit its capacity. With their measurable effect on the forest ecosystems they inhabited, it seems as though it would have been unsustainable. However, if the population had hits its plateau and was sustainable within their ecosystems, then I think they would have continued to be so abundant and had even more success with their numbers due to their abilities to transform landscapes.

    2. In addition to #1, if the passenger pigeon hadn’t gone extinct, do you think their numbers might have ended up leading to another species’ extinction?
    I believe their numbers would have definitely caused a decline in other bird species that occupied the same niche as the passenger pigeon. However, if their populations were stable within their ecology, then I think they would have continued to be the more prevalent species with no major effect on the extinctions of other species besides possibly impacting populations in slight waves.

    3. Do you think the passenger pigeon really had this dramatic effect on forests? If not, what other factors could have influenced the author's data?
    I think it’s really an interesting idea to consider their impact on forests. I am a bit hesitant to accept that the passenger pigeon alone contributed to the shaping of forests simply because of time constraints. I think the effect of humans needs to be more closely examined.

    4. What other species (besides humans) can you think of that affect environments so greatly?
    I think other species that can greatly effect environments are those usually found in lower trophic levels.

    Questions:
    1. Probably in an attempt to preserve parts of the ideal American West.
    2.Why do you think so many laws were passed in the 1800s that were either not enforced? Why were laws passed in states that no longer had bison? How might your answer relate to the first question?
    I think much about how those societies functioned had a lot to do with the law enforcement of them. The laws could have been passed due to outside pressures that were nonexistent in the state- when these individual states had to decide whether or not to enforce the says, perhaps individualized interests took precedent. Laws passed in states that no longer had bison did so as a more symbolic act.

    3.On a global scale, which wild species come to mind when considering a current comparison to the overwhelming loss of bison, or even to the re-establishment of public bison herds in the early-mid 1900s?
    A few species come to mind: sharks and wolves perhaps in the recent past.

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  19. Ellsworth and McComb Paper

    4. Many species have a dramatic effect on their environments, humans of course are the main one but that’s been ruled out by the question asker. Other animals that tend to destroy their environment as a by-product of just living are elephants and prairie dogs/ground squirrels. Elephants will charge right through many strands of trees as well as undergrowth that is perfectly healthy and alive, in their rush to escape predators or get away from whatever spooked them. Prairie Dogs on the other hand often destroy a world us humans rarely see, they make such elaborate tunnels across a vast expanse that they will often cause buildings to become unstable, and they can make walking through a field tricky, as a person can break through the surface of one of their tunnels very easily. A look on the brighter side however are squirrels who greatly affect their environment but in a good way, as since they roughly forget 70% of the nuts they hide each year, they tend to grow complete forests just due to their forgetfulness.

    Bison Timeline

    2. I think that many laws that were passed in the 1800s about bison, were not enforced, because during this time period a lot of the western united states were still not ratified states and in these territories it was very common along with a fair number of actual states that the real people in charge of a town or area were the ranchers in the area. Often the ranchers of an area had the most land and thus the most power, along with several field hands that could be better describes as mercenaries that were used to intimidate people. While they weren’t the official rulers of these areas their money and power allowed them to run things from the shadows. Laws were passed in states that no longer contained bison, because back then it was very had to know when or if an animal was in such a large territory as not many people were living in most of the west yet, and often these laws were passed as a precaution of there still being a few bison left in the state or if a herd happened to move into the area. I believe these laws were ignored until ranchers had established land where their cows were able to eat all of the grass they could without the buffalo herds coming through and tearing down fences while eating all the grass for miles around a rancher’s property.

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  20. Ellsworth and McComb 2003
    1.) Naturally, I believe they would have persisted as they did prior to human interaction. When an animal has been established in an ecosystem for an extended period of time, other forms of life adapt to coincide with that organism. I do not believe they would have exhausted their food sources or dramatically altered their environment to a point where they would have seen an exceptional loss in their numbers. The reason being is because of the timeline of their existence. Obviously, they had been around for awhile so we would assume that the environment had adjusted to their presence already and provided them with the necessary resources throughout time.
    2.) There is always the chance that some organism can alter the survival of another species. However, in the case with the passenger pigeon, I do not believe they would have caused the extinction of another species, had they persisted. Because they had existed in their environment for as long as they did, the animals and vegetation would have adapted or even evolved to exist with them.
    3.) I think it is possible that the pigeon had a large part in shaping the forest. However, the chances are, it wasn't just them. I would argue that climate could have been a major factor in the changing forests. Some plants fare better in some conditions than others. It is possible that changing temperatures or even changes in atmospheric chemistry could have caused change in the forests.
    4.) I think species of small rodents and mammals (e.g. squirrels) could affect environments greatly. Many of them also feed on seeds and plant matter that they too disperse in their feces.

    Bison Timeline
    1.) I think the shift was due to the realization that an iconic species was in peril. Most likely, it may have been due to animal activists and wildlife advocates who argued that this species needed to be saved.
    2.) I do not believe there was the proper resources, man power, or means of transportation to enforce the laws. I also believe that people may not have cared enough.
    3.) The species that comes to mind is the reintroduction of the American Grey wolf. The wolf was deemed a threat to livestock and was killed towards extinction. However, biologists and environmentalists realized the environmental consequence of its removal. They realized that without the wolf, elk ran rampant which negatively affected the vegetation through their consumption. Reintroducing the wolf should help reinsert balance into the ecosystem.

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  21. Had passenger pigeons not gone extinct, I think they would have at least decreased in number due to human involvement. Perhaps they would have led to other species extinction due to competition for declining resources, but ultimately, I do not think that thier numbers would have been sustainable after human introduction. Squirrels that forget where they burrow thier nuts for the winter and end up planting new trees are also little animals that have a big impact. But any keystone species (bees, beavers, elephants, etc.) affect thier environment greatly. I think that once bison declined enough for people to notice is when protection laws came about. However, lack of enforcement or perhaps just not enough resources to enforce the law could have explained why the law was ignored. The law would have spanned over states that did not include buffalo so that maybe people couldn't cross state lines with thier kill.

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  22. If the passenger pigeon hadn't been hunted to extinction, I think their overall population size would have decreased as they adjusted to human settlement. Because human activities led to a decrease in habitat size and habitat fragmentation, there would have been more competition for the remaining resources, which I feel would have led to a decrease in the total population of the passenger pigeon. However, because their numbers were so vast and because they seemed to be well-adapted to their environment (ignoring the human effects on it), I don't think they would have been driven to extinction had it not been for such massive human hunting that targeted these birds. I think it is interesting to contemplate if the population size of the passenger pigeon would have led to the extinction of another species, but I don't really have a solid answer for this. It is possible that they might have led to extirpations of certain vegetation in certain habitats (because habitat size was reduced and so there was less resources to be used among such a big population), but I don't know that they would have led to an all-out extinction. They were an important part of their ecosystem because they were such a large portion of the consumers of vegetation and their large population was a good opportunity for secondary consumers to catch prey without a detrimental impact to the population as a whole (excluding humans).
    I think the overall shift from mass destruction of public bison herds to the donation of live bison to private herds was probably education and firsthand witnessing of the detrimental effects that the extirpation of the bison had not only on the Great Plains but also further south and north into Canada. I think it's very easy for people to ignore the possible consequences of their actions until they see firsthand their effects; it's easy to say, "Well, killing bison might not be the best idea, but how bad can it really be?" I think the shift in public opinion came after people saw how the land suffered in their absence: soils weren't as fertile and wouldn't grow things efficiently and predators had lost an important prey item that forced them to look elsewhere for food or risk extinction/extirpation. As for why laws weren't enforced in the 1800s, I think it also ties in to not fully understanding/believing the consequences of losing a key species in an environment. In addition, as was discussed in class, the mass hunting of the bison was an attempt by the government to control Native American tribes and force them onto reservations. Not only did the government not seem to believe the consequences of bison extinction, but they also used bison as a way to manipulate and further control Native Americans.

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  23. I think that passenger pigeon populations would have inevitably thinned due to the habitat destruction of forested areas , which would have led them into urban areas. I could not imagine that birds of that size would be able to adequately provide for themselves (food and shelter wise) in urban areas , nor would humans allow these massive birds it roam the streets or perch in their trees if they caused damage . Although we'd like to try and understand the "what if " had humans not intervene, there is no way the human race would allow these birds to continue if they caused any type of inconvenience in daily life.. We already see people kicking pigeons on the sidewalks simply because they're in the way, I can't imagine people being any kinder to passenger pigeons.

    i think the shift of destruction of bison to their preservation was due to the realization of the impact these animals had on the environment. Before they were used as a political pawn to control the Native Americans, so their importance was more of a "right here right now" kind of deal, but the government wasnt really thinking of the future- it was important for them to manipulate the Natives, and increase the profitability of cattle ranches at the time.

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  24. For the passenger pigeons article, I think that the main reason that they went extinct was due to the excessive hunting for their feathers and for their meat, as well as pure hunting for sport. Without humans hunting the pigeon to extinction I think that they might have gone extinct on their own. Nothing lasts forever. Their habitat was destroyed as they roosted within the chestnut trees and with the blight and the mass harvesting of the chestnuts I personal think that they would have not been able to survive through the lost of their habitat.

    For the bison, I have to say that if we look back in history the main reason (in my opinion) for the destruction in herd number of bison, was the white Europeans in cohorts with a tribe of indigenous peoples, the Comanches. Its was the Europeans that gave the Indians guns and horses which allowed for them to hunt more efficiently as well as the Hyde trade that took place shortly after. Also, the sport hunting from trains that took place during this time in history. Many of the laws that took place after the massive hunting of the bison and the passenger pigeon were place in order to protect any and [all] species that were being hunted. I think a species that comes to mind is the sharks and other sea life that is hunted due to finning.

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  25. Considering their detrimental impact on non-native environments, these pigeons would have likely caused collapse of their required habitats and could have caused themselves to go extinct. They could have also been subject to predatory birds and more effective species in the same niche. If they continued to grow, their huge numbers and impact on non-native ecosystems would have surely caused other species to suffer or go extinct as they damaged or depleted habitats and ecosystem structure.

    Earlier laws were likely not effective because they couldn’t be enforced. In modern times, we have more advanced, real-time monitoring and conservation strategies and tools that allow us to effectively enforce laws such as the one in 1905. This loss of species reminds me of the present declines in wolf and bear species.

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