I have been waiting for Dr. Paulson to enter into the fray because it has
been so long since I had any biology courses. However, I will attempt to
recall what I learned in Zoology so many (40???) years ago, from him and
severaql other professors. Please remember it has been 40 years, so exact
spelling or terms may be a little off - and I am far from an expert on the
Order of Aves.

If I remember correctly, there is a different hemoglobin, called
met-hemoglobin, in the dark meat of birds. It has a higher oxygen carrying
capacity than normal hemoglobin. The birds that fly long distances, ducks,
etc. have this type of hemoglobin in their flight muscles. The ground
dwelling birds that tend to run more (turkey, chickens, etc) have the
met-hemoglobin in thigh and leg muscles.

This is the black and white of the issue.

Of course, there is always a gray area. Biology would not be fun if
everything was black and white. Where would be be if gulls did not cross
bread or if they started out white in their first year?? Identification of
them would be so boring!

Perhaps the birds that are, for example, ground dwellers but do not have
dark meat for their "running muscles" have "recently" become ground dwelling
birds. Maybe they lack the gene/s for met-hemoglobin? Maybe convergent
evolution will occur in the next million years and they will develop
met-hemoglobin in their running muscles. Maybe all birds have the genes for
met-hemoglobin but it takes a slight mutation to turn them on. - - - Maybe
it will only be 10,000 years!

Questions that have occurred to me from these e-mails -

Does any Zoologist know if small ground-dwelling birds (Dippers, Towhees,
etc.) have met-hemoglobin in their leg muscles? Is it all or nothing for
met-hemoglobin? Is there a mix or ratio of hemoglobin to met-hemoglobin in
bird muscle tissue? If so, this would answer the above question about all
birds having the gene/s for met-hemoglobin. Does a quail or chucker have
some met-hemoglobin? Does a gull have met-hemoglobin in its flight
muscles? What about all the birds that are not "game birds? has anyone
looked at them?

Is there a doctoral thesis here??

What ever the answers are, it sure makes birds interesting to study and
think about!!

Will Markey
East of Auburn on Soos Creek
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