Friday, September 17, 2010

One Link...

Long day, more visitors coming. But my speculations on the nature of the passenger pigeon at Living Bird are now online. Check them out and let me know what you think?

15 comments:

PBurns said...

A nice piece!

There's one idea I wish you had expanded on a bit, and another I wish you had mentioned (though I DO realize space is ALWAYS short in these things).

The bit I wish you had expanded on is the line "...impossible to sustain them in the numbers they had been accustomed to for breeding...."

The Passenger Pigeon seems to have been an animal that needed to be in flocks of hundreds or even many thousands in order to stimulate estrus and mating. Basically, the only sex a Passenger Pigeon had was group sex so far as anyone can tell. No group, no sex.

What that means is that this is a species that could NOT be pushed to the edge and brought back. Most other birds are not this unlucky, which brings me to point #2....

It is surprising how FEW birds or other species have been pushed into extinction in the U.S.

In fact, when we look at true species (no Heath Hens, thank you very much!), it is very few.

A final bit is that while we have lost species in the U.S, we have also gained some. We have lost one native pigeon, we have gained at least one or two foreigners.

And on the parrot side, we have lost one species, and gained over a dozen foreigners.

Again, these may be side cars....

What you have written here is a nice solid piece all by itself. Not sure the sidecars fit...

P.

Steve Bodio said...

Thanks Patrick.

First: you are right magazine word limits are tight. And this is basically a book, with an intro longer than the piece and then a proposal, which no publisher wants to take a chance on at the moment.

Second point- you are not the only one to raise it- someone who has an interesting site called I think Georgia before humans ( have been to busy to read it yet) said so too, and thinks there was enough forest in the South to sustain them.

On the second point I am agnostic-- I would have to read a lot of papers and crunch a lot of numbers. But my bigger argument is that THEY HAD TO GET THAT WAY-- at one point they had to evolve mass breeding. The questions then become WHEN and WHY? Those are my questions-- and I think it could have happened faster than we used to think.

Neutrino Cannon said...

Wow, just wow.

I didn't realize that Passenger Pigeons needed to be in those huge clouds to breed. Avian locusts...

Cat Urbigkit said...

Excellent piece!

smartdogs said...

This quote really struck a chord with me:

>>In the words of Jeffrey Lockwood, entomologist and ecologist: “Ecology is beginning to slowly shift focus with tentative explorations of what the world would look like if process, rather than matter, were the basis for reality. What if we defined a species in terms of its life processes?”<<

My background is in aqueous geochemistry, the study of natural waters. The idea that ecological processes are be more important than individual organic and inorganic actors, and the fact that ecosystems exist under conditions of dynamic equilibrium rather than being "stable" are the foundation of much of that work.

Microorganisms are vitally important in water chemistry. In many cases we find that small changes in the physical environment can create dramatic changes in the biota - which then change the chemical environment. We study the life cycle of the system rather than those of its constituent species. It's exciting to see new work where these ideas are being applied to larger and more complex systems.

Reid Farmer said...

I have never been able to get past the fact that Passenger Pigeon remains barely appear in the faunal record of prehistoric archaeological sites in the eastern US. This is the basis, I believe of Mann's interpretation that PP populations boomed only after Native American populations crashed

Steve Bodio said...

Smartdogs: Lockwood is an occasional correspondent though not as far as I know a blog reader. You prompt me to send the link to him for comment-- especially (NC) he has written a book about the amazing extinct locusts of the Great Plains, whose mass was only exceeded by (?) buffalo and the PP.

(Offside comment to NC: I ordered those "drop in" replacement aperture sights you recommended for the SKS).

Reid: the Georgia guy DID cite some associations (really have to find and link his blog). But according to the recent hard science bird evo and anatomy book I will review (Gary Kaiser), one reason bird taxonomy is in such flux and generates so much heat is that birds fossilize badly and that there are too few, period--??

Mark Churchill said...

I know of several places in the Southeast famed as passenger pigeon roosting or nesting sites (for example, Pigeon Forge, Tennessee and Ayeli Alohi—the Cherokee's "center of the world" near present-day Hartwell, Georgia) and have often tried to visualize what they must have looked like back in the day.

Now I'm trying to visualize (thanks in part to Neutrino Cannon's "avian locusts" comment) what 210 million liters of food a day would look like: how many boxcars, for example.

If the demise of the passenger pigeon was detrimental to ivory-billed woodpeckers and peregrines, was it equally a boon to mast-eating competitors like grey squirrels, wild turkeys, and white-tailed deer? And then the cascades from the abundance of those species, most notably the deer that are currently decimating some rare plant populations in the east...

As with any ecological question, there's no shortage of stuff to think about, and that's without even getting into the question of how the passenger pigeon became a density-dependent breeder. Great article, Steve.

Josh said...

Mr. Bodio, I've just come across your link, and will read it tomorrow. In the meantime, I'm struck by Mr. Leopold's description in your introduction, as it is yet another example of impacts prior to modernity. Lately, I've become interested in describing an accurate accounting of how our impacts can be made more positive, even the big ones. Among the thoughts that have led me to consider this include the replacement of large, omnivorous megafauna in California (bears to pigs), the loss of billions of pounds of nutrients in California landscapes by the loss of salmon runs, and the replacement of large, hoofed ungulates (approx. the same number of large bovines in North America today as 200 years ago, they are just a different species, and they and the native species are managed to be much more sedentary than before).

Being from California, I've been interested in how our diverse flora (more taxa than all other states, combined) can withstand our changes to the landscape. Your pigeon article is yet another example for me to study. Thank you.

Steve Bodio said...

Josh-- I think that the "re-wilding" people like Paul Martin are thinking on these lines. Have you read his Twilight of the Mammoth or Connie Barlow's Ghosts of Evolution? The second is actually more specifically about the subject but Martin, one of the first proponents of the Pleistocene overkill hypothesis, is a character in her book and a primary reference.

Martin once handed me a piece of 12,000 year old ground sloth dung from the Grand Canyon.

Steve Bodio said...

Oh and-- thanks, Mark. One does wonder about things like the overabundance of whitetails.The usual reason given is lack of predators, but with generous human limits and ubiquitous large coyotes I don't think that is the whole picture (good article on urban ecology and the healthy NYC coyote population in the September edition of New York magazine).

cantdoghill said...

Steve, Excellent article . The passenger pigeon's flame out suggests to me a population almost absent of genetic variation vulnerable to both internal and external change. The ensuing pinball effect altering the selective pressures on dozens of other species is a fascinating statement about the interaction of ecology and evolution.

Steve Bodio said...

Cantdog (John V?); the idea of lack of genetic variation is one I hadn't considered and ought to dig into-- thanks!

Josh said...

Mr. Bodio, I have not read these, and I will. I'm not an adherent to the overkill hypothesis (there was much in the climate to knock out a number of animals), but I'll still read them.

I would love for a famous archaeologist to give me sloth dung one day. Sadly, my brother-in-law and his wife work in the pre-Cambrian mass extinction periods...

Steve Bodio said...

Josh-- I believe in "Overkill" in places, but think there may have been other factors in North America (partially a synthesis with material so far unpublished, in correspondence with Valerius Geist among others). Paul Martin is still a great scientist and innovative thinker, and a gent besides. That dung was a high point in my naturalist's life!

(He was my wife's oldest brother's thesis advisor, and is a friend of "Alpha Enviro" Jonathan Hanson and his wife, so we have multiple contacts).