Recently Lilian Shen posted the following to our Thetford town news group.
I thought you all might like to see it, too.
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Bird Language and Loves 						

The much-overdue onset of spring brings with it dramatic changes in bird
behavior.  The chickadees that overwintered near our house have changed
their
tune, filling the air with loud calls of 'Fee-bee-ee.'	As soon as one
calls,
another replies.  The musical back-and-forth is repeated over and over, and
for good reason. The male birds are proclaiming their territories. This
important message is just one of about fifteen different calls in the
vocabulary of chickadees, and biologists have managed to interpret eight of
their 'words.' 
Chickadees mate for life and 'Fee-bee-ee is also a 'love' call to maintain
the bond between the male and female.  

These birds have a social structure, that is established when they flock
together in winter and they observe this pecking order during the rest of
the year. The call that sounds approximately like 'tseedl-deet' or
'se--tseedl-deet'
is given by a bird higher in the order to warn off a bird of lower status.
It would mean something like "Buzz off" or "This is MY food."  The chatter
call, something like a rapid-fire 'chi-chi-chi-chi' is given by the dominant
bird when it has successfully driven off the other, and would mean something
like "That'll teach you!" The familiar 'Chickadee-dee-dee' call is often
used to signal danger. In this case the number of 'dees' increases in
proportion to the severity of the threat. Thus large predatory birds that
are not nimble enough to catch a chickadee get about five 'dees.' whereas
small predatory birds that are a real threat get up to 23 'dees.'  I notice
that I get about five 'dees' when I
approach too closely.	The 'chickadee-dee' call is also used repeatedly
when
the birds discover a predator and gang up to mob it. 
A short 'czeet' whistle may serve to keep members of a flock together ("Here
I
am.")

Female chickadees utter a repeated, buzzy 'dee-dee-dee' to attract a mate
during breeding season and to maintain the pair bond. They also listen
attentively to the singing contests between their mate and a rival male. The
outcome of these
musical duels is highly significant and woe betide the male who loses.	His
spouse will quietly slip away, usually at early dawn, and will mate with the
winner. After this quick tryst, which lasts about 30 seconds, she returns as
if nothing happened and continues to stay with her mate. Although the chicks
in the nest may thus be the offspring of more than one father, the male
seems oblivious to this. 

Although chickadees mate for life, divorce is not unheard of.  Even birds
like to climb the social ladder, it would seem. At the head of the chickadee
flock is the alpha male and his mate the alpha female. Next in rank are the
beta male and beta female, and so on.  The flock may also include some
unpaired birds. If the alpha female dies, the beta female deserts her mate
and pairs with the alpha male, thus gaining rank. The beta male may pair
with an unpaired female if one is available. If the alpha male dies, the
beta male usually moves up to take his place, and his mate. This social
climbing has many advantages. Lower-ranking birds defer to alpha birds and
allow them to get the best forage and the best nest sites.  Furthermore,
since the alpha male wins more singing contests he fathers chicks 'out of
wedlock' as well as with his mate and thus spreads his
genes more widely.   

Submitted by Li Shen
Thetford Conservation Commission
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John Walker
[log in to unmask]
East Thetford, VT

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