I previously blogged about how to tell Purple from House finches. Over the next three days, I banded 10 Purple Finches. The most interesting of these birds was the following individual.
After eating seeds at the feeder, this bird flew up to a maple with sap running down its trunk (see last photo). The bird spent almost a minute drinking from the tree. Curiously, Wootton (1996), in the definitive Birds of North America, does not mention Purple Finches' drinking sap. A cursory internet search came up with a citation by Lange of finches drinking Box Elder sap. In 1900, Lange wondered, in the unscientific magazine Recreation, if Purple Finches (and other sparrows) drink sap for the sugar or the water. He suspected water. I think a sugar solution would supply energy for many migrants.
After eating seeds at the feeder, this bird flew up to a maple with sap running down its trunk (see last photo). The bird spent almost a minute drinking from the tree. Curiously, Wootton (1996), in the definitive Birds of North America, does not mention Purple Finches' drinking sap. A cursory internet search came up with a citation by Lange of finches drinking Box Elder sap. In 1900, Lange wondered, in the unscientific magazine Recreation, if Purple Finches (and other sparrows) drink sap for the sugar or the water. He suspected water. I think a sugar solution would supply energy for many migrants.




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