The Effect of Dietary Protein and Feed Size on the Assimilation Efficiency of Starlings and Blackbirds

Starlings (Sturnus vulgaris) were fed 3 feed sizes and 3 protein levels of swine feeds to determine metabolizable energy and assimilation efficiency. Metabolizable energy (12 kcal/g of diet consumed) and assimilation efficiency (3296 of gross energy intake) were independent of feed size. A 46% crude protein diet was 5196 assimilated and yielded more energy per gram of diet consumed than a 2196 crude protein diet which was only 35% assimilated. Starlings failed to maintain their body weight on a cracked corn diet containing 14% crude protein. Feeding behaviors of starlings due to their assimilation efficiencies are discussed and contrasted with the feeding behaviors sad assimilation efficiences of Icterine blackbirds.