CONSEQUENCES OF AN ALIEN SHRUB ON THE PLUMAGE COLORATION AND ECOLOGY OF CEDAR WAXWINGS

Cedar Waxwings (Bombycilla cedrorum) with orange (instead of the norma l yellow) tail bands have appeared in eastern North America in the las t 35 years. Biochemical studies have implicated a dietary cause (Hudon and Brush 1989), specifically the fruits of Lonicera morrowii (Brush 1990), for this novel color variant. I show that rectrices replaced wh ile Cedar Waxwings are feeding on L. morrowii fruits develop orange ti ps. Rectrices replaced subsequent to switching the diet of molting wax wings from L. morrowii fruits to dog chow were yellow, showing close t emporal correspondence between dietary input of rhodoxanthin and the c oloration of growing feathers. In the Ithaca vicinity, fruits of L. mo rrowii are eaten by wild Cedar Waxwings from June until mid-October. T he extended pattern of availability and consumption of Lonicera in thi s region appears to explain my unique observations of adult Cedar Waxw ings growing orange tails during the fall months. Cedar Waxwings maint ained body condition and molted while on an extended diet of L. morrow ii fruits (36 days for two birds and 64 days for two others). Three bi rds initiated tail molt while on this diet, including one that molted all of its night feathers. These results emphasize the nutritional spe cialization of Cedar Waxwings to a diet of sugary, low-protein fruits, and show that molt occurs in an apparently normal manner when birds a re eating a low-protein fruit diet.