A few days ago, I posted a request for information about the decline of Greater Prairie Chickens in Missouri. I framed the question both generally throughout the state and specifically about at places like Taberville CA and Dunn Ranch. Bob Foreman and others posted replies that provided general reasons for the species decline in the state and which may explain why it has diminished at Taberville and Dunn Ranch. Please tell me if I got it right.
As best I understand them, the answers are as follows:
(1) General decline: If Greater Prairie Chickens were to make it in strictly native tallgrass prairie habitat, they would need very large tracts of undisturbed prairie. Tracts of that size no longer exist in Missouri. Nevertheless, chickens have continued to survive by using combinations of native prairie and nearby farmland. The decline has occurred because (a) landowners have continued to convert native prairie into farm land and (b) they have continued to break up and change the uses of  farmland adjacent to native prairie in ways that make it less hospitable to the chickens. In effect, they have squeezed surviving chicken populations into smaller areas of hospitable habitat, limiting the size of the population a given area can carry. Chickens suffer a lot of mortality in cold wet years and their reproductive strategy counts on a large population buildup in warmer dryer years to maintain a balance. When the total carrying capacity of an area is too small, the buildup in good years is insufficient to offset the decline of bad years; the population fails to recover and eventually dies out after a series of bad years.
(2) Specific decline at locations like Taberville CA and Dunn Ranch: The native prairie is by itself insufficient to sustain a population. Fragmentation and tilling of surrounding farmland has reduced the population capacity of the overrall area below sustainability.
If what I have written above indicates that I have it right, the one problem that remains for me is that I have not noticed that much change in the farmland surrounding Taberville Prairie in the 37 years I have been watching chickens there. If the area were unsustainable without change in the surrounding farmland, why would the birds have lasted 37 years?  Has there been significant change that I have not noticed, or has it been large enough (i.e. almost of sustainable size) so that the decline has been gradual?
Finally, assuming that it would be difficult to buy thousands of acres of farmland around Taberville or Dunn Ranch and convert it to something like native prairie,  could MDC have saved the birds by acquiring conservation easements that limited the amount of change in surrounding farmland?
I'd appreciate a little more wisdom for this interesting thread.
Bob Fisher
Independence, MO
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