EXPERIMENTATION. 



EXPERIMENTS WITH CAPTIVE BIRDS. 



Experiments to determine the kind and quantity of food, and the 

 time of digestion have been carried on. Nestling birds, because they 

 were most available, were used in the experiments. The birds were not 

 allowed any food for a long enough time to insure an empty stomach. 

 They were then fed a certain amount of food. After varying periods 

 of time they were killed and the stomachs and intestines examined. 

 The position and condition of the food (recognizable hard parts) in the 

 stomach and intestines at intervals after feeding, afforded evidence as 

 to the time of digestion. Evidence as to the food of nestlings has also 

 been obtained. A daily weighing of the nestlings and their excreta 

 has furnished evidence as to the quantity of food required. 



The results can be summed up as follows : 



1. Meadowlarks have a great capacity for food. A nestling was fed 

 twenty-eight grasshoppers (one half inch in length) inside of fifteen 

 minutes. 



2. The time of digestion of grasshoppers and beetles is two to four 

 hours. Cut worms are digested more quickly. 



3. The time of digestion of grain (wheat) is three to six hours. 



4. Nestlings are fed almost exclusively on insects cutworms, beetles, 

 and grasshoppers being the principal items. 



5. Nestling meadowlarks consume about their own weight of food 

 every day. They gain very nearly one fourth of an ounce in weight 

 each day they are in the nest. 



LABORATORY EXAMINATION OF STOMACHS. 

 COLLECTION OP NON-GAME BIRDS. 



Collections of birds in sufficient numbers to furnish reliable data, 

 collected every two weeks during the year, and from over twenty-five 

 different localities in the State, have been made available through the 

 co-operation of the deputies of the Commission. Each bird has been 

 tagged with data as to date, time of day, locality, kind of field or 

 orchard, and name of collector. They have then been preserved in 

 formalin solution and shipped to the University. On the arrival of 

 shipments at the laboratory the stomach has been removed and data 

 as to the species and sex of the different birds added. The tag bearing 

 complete data has then been wrapped with the stomach in a small cloth 

 and preserved in formalin solution until microscopically examined. 

 Although the collection of non-game birds by the deputies for the inves- 

 tigation has often been interfered with by the absence of the deputy 

 on important work, or by the replacing of deputies, yet series of birds 

 taken each month of the year fn sufficient numbers to furnish reliable 

 evidence as to their food are at hand from many different localities in 

 the State. So far as possible all incomplete series will be completed 

 this coming year. 



