Yesterday I got an email from the USA;
Hello, Mr. Avery. My name is ***********[girl’s name] and I’m a 9th grader at ********** North Junior High. I am doing a class project on passenger pigeons, and I see that you have quite a bit of expertise on the subject. A lot of people have varying opinions on the topic of passenger pigeons. I am curious to know what you think about certain things.
Here are the questions and my answers:
Do you think that passenger pigeons would be able to survive in North America today? Why or why not?
That’s a good question and the answer is yes and no. I think there are plenty of nest sites, and plenty of food for them, but I think we would have to get from zero Passenger Pigeons to millions and millions of them before they would survive and prosper. And that’s because I think that they depended on living in huge flocks, and particularly nesting in huge colonies, to swamp the impacts of predators. When a massive flock of Passenger Pigeons set up a colony in Minnesota then lots would die from predation by hawks, squirrels, bears etc etc but although it was a very large number it was probably a very small proportion because the colony was so huge that local predators could only dent its numbers. So yes, in theory because there’s plenty of food and nest sites, but no in practice because they’d be wiped out easily by predators.
Why do you think passenger pigeons went extinct?
We cut down lots of their forests and we shot/trapped lots of them for food – and none of that can have helped them. But those things, I think, weren’t big enough factors to wipe them out. I think they went extinct because they could no longer swamp the impacts of predators (as above). But it’s a bit of a guess.
What do you think the world would be like today if passenger pigeons were still alive?
Amazing, if they were numerous. I’d love to fly back to the USA and see a Passenger Pigeon colony or winter roost. I’d love to stand and look upwards and see a river of birds flow over my head for hours at a time. And they’d be on TV a lot. They might be a bit of a hazard around airports sometimes though.
How did the extinction of passenger pigeons affect the United States and Canada?
It must have been in quite a big way because over 100 years after the last Passenger Pigeon died in Cincinnati Zoo, Ohio, we are still talking about them. I don’t think the ecology of the USA has changed much – the relative abundance of some trees may have shifted in the absence of Passenger Pigeons eating their acorns but not hugely.
How did the extinction of passenger pigeons affect their ecosystem?
See above – not hugely.
How many passenger pigeons once lived in the wild?
People differ on this – and it’s very difficult to tell. If I had one trip on a time machine I’d like to go back and find out. My guess is about 10 billion – others say fewer, but that’s my guess.
How would reintroducing passenger pigeons to the wild today affect the ecosystem?
Not very much, but it would be very difficult, I think, because one would aim to reintroduce millions, not just a few birds.
How would reintroducing passenger pigeons to the wild affect people?
If they became really numerous again there would be gains and losses for people. They would be pests of crops in some places, I guess. They would be an air safety hazard. But they would be a natural spectacle that would be seen by tens of millions of Americans each year. And they apparently were good to eat.
If they were still alive today, how would climate change affect passenger pigeons? Would they feel the effects of it yet?
Good question! I don’t know but I guess there would be many impacts. They would probably nest a week or two earlier because snow clearance would occur earlier. Maybe they would migrate less far south and spend more time hoovering up beech mast and acorns. Very good question.
What can we learn from the extinction of passenger pigeons to prevent something like it from happening again?
We should learn that when we lose a species we don’t gain much, so it would be better if we found a way to conserve species. We look like idiots if we wipe out species with no benefit to our own species. How daft is that?
I get quite a lot of requests for help a bit like this one. I aim to answer all of them but I don’t always get round to it – sorry! And not all of them are so well expressed as this one so I felt quite highly motivated to answer this young lady’s questions. And so it took some time. And so the blog that I might have written didn’t get done. So I am showing you my homework instead.