Print

Print


Gonna try to cover a few prairie chicken issues with one email, so
hopefully this doesn't get too long or cumbersome. No promises :-)

Regarding farm expansion and the prairie chicken: Missouri's peak time
for prairie chickens actually occurred when MO's prairie areas were
roughly half prairie and half farmland, around 1870.  Reasons--waste
grains from farms helped prairie chickens survive winters, and farmers
often cleared wooded areas, increasing open landscapes. This has been
very well documented in other neighboring states too. Human settlement
could actually be such a positive influence for prairie chickens that
it not only increased their densities, but increased their range, even
into areas that had been almost entirely forested previously, such as
parts of Wisconsin where Leopold studied them that prior to white
settlement had been almost pure jack pine forest. Conclusion--it's not
as simple as agriculture=bad for the prairie chicken. I will sit out
the debate of who is to "blame" for the loss of the old-school family
farm, but the historical evidence overwhelmingly supports the idea
that diverse, small scale farming that preserves some grassland
acreage is quite compatible with prairie chicken presence, and that
our current model of farming does not.

Let's take Bob Fisher's example of Taberville. I've only visited
Taberville once and have no historical frame of reference for the
area, so let's just say that the surrounding habitat is in the same
usage it was 37 years ago. Here is my best guess: technology and
farming practices have changed a lot since then, even if it doesn't
change the visual appearance much.  A hayfield is not always the same
hayfield--how many times was it mowed last summer? Once? Three times?
Huge difference to the chickens. One mowing in mid-July can be neutral
or even beneficial, three mowings all but assures a hen nesting in the
field will have a chopped up nest and no winter cover. A cornfield is
not always the same cornfield--what kind of harvest methods are the
farmers using? Is it leaving as much waste grain? Are farmers leaving
up their wheat stubble, which chickens prefer?  Are there more cattle
on existing pastures, changing the grass from moderately grazed
(beneficial) to heavily grazed (detrimental)? All questions I do not
know the answer to for this area. But I would place a large wager that
changes have taken place, even if they are not changes easily
registered to the eye.

As for weather... my theory is based on nowhere near the amount of
data that my other conclusions are, I'll state from the outset this is
more of a hunch, and is only a consideration within the larger picture
of habitat degradation. It's based on a study I read on Attwater's
Prairie Chickens back from when there were still some wild ones left
on coastal prairies. It characterized Attwater breeding success in a
sustaining population roughly as such: out of every 5 years, two years
would be almost a total loss, two years would be a slight net loss,
and one year would be a good year. The primary variables examined were
temperature and precipitation during the days when chicks had just
hatched. Obviously, prairie chickens developed an evolutionary defense
for this-- large clutch sizes, which also helps with the predation
problem. If there is a good year, hens can crank out a lot of
chicks... as long as there are enough hens and safe places for them to
nest.

Let's say that the Attwater's is different enough from our Greater
Prairie-Chicken that you can't extrapolate those facts exactly-- I
still think the strategies and weather phenomena are close enough to
make some worthwhile comparisons. And, given the cold, driving rains
we've had in late May and early June in most of last past several
years, it might help explain why things have gotten so terrible
despite some good habitat work. I won't fault someone for not buying
this-- but I think it's possible, and the nesting data I saw for
turkeys in MO the past few years (horrible, especially one and two
years ago) seems to add a little verification, as poults are
vulnerable to the same things.

If I could characterize why things have gotten so bad, I might borrow
a phenomenon from the social sciences. The Gestalt theory of
psychology (birders are familiar with it from the term jizz, or gizz,
or giss, or whatever, as it pertains to ID factors) states that the
whole is greater than the sum of the parts. So it is with the threats
to the prairie chicken.  No problem exists in a vacuum-- so let's list
some of the threats.

Major:
--Loss of permanent grassland habitat
--Degradation of existing grassland habitat

Moderate/Minor:
--Loss of diverse grasslands (native grasses, forbs), or beneficial
species of non-native grasses
--More efficient, mechanized agriculture leaves less waste grain for
winter feeding
--Possible increase in predators
--Series of cold, rainy days at inopportune times recently


These are a few, but they will work.  Each problem serves to compound
upon the other, making the whole greater than the sum of the parts.
For example, loss of permanent grassland habitat means fewer areas for
nests, which makes a possible predator increase a much larger problem
than it would be on its own. Loss of diverse habitat with many species
of plants means there might be fewer thick clumps of chosen grasses or
forbs to nest in, which makes hens more vulnerable to nest predation.
Grassland birds are amazing in their ability to nest near species of
plants that either help conceal from or deter mammalian grazers and
predators--given that these plants are still there.

Long story short--when so many factors compound upon one another,
relatively minor changes, as part of the whole picture, become quite
problematic--even catastrophic.

If one wants more detail, I would consider reading the paper at the
following link. It covers more than I can cover here.
http://mobirds.org/Articles/HistoryofGPCH_MO.pdf I looked at the
prairie chicken problem as a social scientist might. (I hate it when
people push their own work, but it might help some folks see more of
the historical picture). I welcome critiques of the paper too, I'll be
the first to admit it needs a few minor changes.

One last thing: it is easy to view the prairie chicken as a somehow
weak or helpless creature, unable to cope with modernity because of
ineffective survival skills or adaptation. No way. Prairie chickens
are survival machines that adapted to a very difficult place to live:
a bird that can survive a Minnesota winter and a Missouri summer using
only grasses for cover; a bird that can routinely outfly a Peregrine,
even making the former look like it is standing still in level flight;
a football sized-bird that nests on the ground within reach of the
entire suite of an ecosystem's predators and some still live to "tell
the tale"-- it is an amazingly well adapted bird that deals with a
number of regular threats that make our daily lives seem like
cakewalks. I have heard some people say (mostly non-birders) when I
have described the situation that prairie chickens sound too picky or
not suited to survival threats in a tough world. I've flatly refused
to see the prairie chicken on those terms, and I think everyone else
should as well.

Thanks for bearing with the novel here. For those of you who read this
at work, have your employers send me the bill for the lost hours of
productivity ;-)

Phil Wire
Edwardsville, IL, Madison Co.
[log in to unmask]

------------------------------------------------------------
The Audubon Society of Missouri's Wild Bird Discussion Forum
To unsubscribe or change subscription options:
https://po.missouri.edu/cgi-bin/wa?SUBED1=mobirds-l&A=1