FOOD AVAILABILITY AND PRIMARY FEATHER MOLT IN EUROPEAN STARLINGS, STURNUS-VULGARIS

The effects of food quality and overall food intake on molt have been experimentally investigated in a number of species. However, little is known concerning the influence of periodic food availability on molt parameters, although there are some associations in the field. In this study, we experimentally manipulated food availability through food d eprivation during the molt of adult and juvenile European starlings, S turnus vulgaris. By monitoring molt scores, wingtip shape, and lengths and length asymmetries of primary feathers during molt, we demonstrat ed that food deprivation can influence molt. Food-deprived juvenile st arlings exhibited slower feather growth rates, although the duration a nd rate of molt were not affected. There were no differences in wingti p shape between food-deprived and control birds at the end of molt for either adults or juveniles. We also observed erratic reshedding of pr eviously molted primary feathers in juveniles, although this did not a ppear to be related to the experimental treatments. The results of thi s study imply that feather growth rates and shedding rates are differe ntially affected by food availability: growth rates may be decreased w hen food deprivation occurs, whereas shedding rates are relatively una ffected.