Twenty five common buzzards randomly picked at the reception of the Hellenic wild life hospital and Rehabilitation centre Aegina, Greece were weighed and put in separate well ventilated paper boxes in a large room(30m x 15m x5m). At entry, the birds weight ranged from 499g-796g.They were weighed 4 times during the study at fairly regular intervals. The birds were fed on chicken with bones every morning. A control was set up in a 26th paper box in which the same quantity of meat was placed but without any buzzard. The control was to find out the quantity of moisture lost to the atmosphere through evaporation.The moisture lost daily was recorded and the average computed and corrected for in calculating the average quantity of food consumed by the buzzards.A unit increase in the average quantity of food consumed per day and the initial weight resulted to a corresponding increase of 1.495 and 1.265 respectively in the final weights of the buzzards. The approximate daily food consumed by a buzzard of average weight of 691g was 115.1g which translates to 16.7% of its live body weight. The initial weight is significant in predicting the final weight with the criterion P value < 0.05.The range of weight gain for the studied buzzards was (2.7%-32.9%) with an average of 19.4%. The approximate daily quantity of food consumed by a common buzzard of average weight of 691g was 115.1g which translates to 16.7% of its live body weight.