Recently Lilian Shen posted the following to our Thetford town news group. I thought you all might like to see it, too. **************************************** 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 ***************************************** John Walker [log in to unmask] East Thetford, VT **************************************************************** To post messages, send e-mail to: [log in to unmask] Set your e-mail application to PLAIN TEXT ONLY to post messages. To contact the list owner: [log in to unmask] ---------------------------------------------------------------- Web based archives and subscription management are available at: http://listserv.dartmouth.edu/Archives/uv-birders.html ****************************************************************