I received several responses to my post about the odd Mallard with a mix of female and male characteristics. All but one suggest this emergence of male field marks can happen to very old females. Eric DeFonso astutely sent the message below which contains
a link to an article that might be a very good explanation of this phenomenon. I thank everyone who responded.
Learning something new so early in the day takes the pressure off the rest of it, and now I can just watch the NFL (another example of a once robust sport species that has lost many of its former characteristics (long pass plays, quarterbacks who last an entire
season, games not dominated by official reviews, screaming fans, etc).
Dave Leatherman
Fort Collins