THANKS JEFF. FURTHER HELPFUL COMMENTARY FOR ME, AND I HOPE OTHER READERS AS
WELL. MY COMMENTS BELOW THUS: ****........**. REGARDS. RICHARD
I think you have misunderstood what Stephen was saying, three factors to
consider.
1- a given population of Brown Falcons say at Werribee or where ever, does
not consist of a number of different morphs. The differences in plumage are
primarily the result of differences between the sexes overlaid by increasing
paleness as the individuals get older. ****THIS WAS INDEED MY UNDERSTANDING
- AS REPORTED BY PAUL McDONALD FROM HIS RESEARCH AT WERRIBEE. HOWEVER I LOOK
FORWARD TO READING HIS ORIGINAL ARTICLE (A COPY OF WHICH I NOW HAVE).**
2- there are regional differences eg. birds in Central Aust are paler more
"Kestrel like", birds from the Kimberley are very dark. There are other
features of difference between these regional types beyond pale and dark
which I am not going to go into here, but the important thing to understand
is that a pale regional type from Central Aust and a very old pale male from
Werribee are not the same thing, they don't look identical. Same for the
dark Kimberley/Top end birds, there is no equivalent found elsewhere. These
are regional types. ****THIS IS HELPFUL CLARIFICATION OF REGIONAL
DIFFERENCES, OF WHICH I WAS LESS AWARE.**
3- yellow cere is apparently only found in the older males especially the
pale Central Australian population, Stephen suggested this may possibly be
because they are for unknown reason more likely to reach the prerequisite
older age. ****THAT WAS MY UNDERSTANDING OF WHAT HE MEANT.**
Cheers Jeff.
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