191-t] BrijanI: Economic Status of file Western Mcadowlark 411 



fly. one beetle, and five ants. A third one w;is fed thirty graiu.s 

 of wheat inside of ten minutes. 



Weighings of nestling birds demonstrated the fact that they 

 gained very nearly seven grams (0.6 ounce) in weight daily. 

 Solid excreta averages 0.48 gram. The weight of excreta voided 

 during twenty-four hours must be near 3.6 grams, thus making 

 the weight of food required daily over ten grams. This com- 

 putation does not take into account the weight of excretory 

 products given off through the skin or the weight of carbon 

 dioxide given off through respiration. The ratios of solid, liquid, 

 and gaseous excreta are not known. The tabular results of 

 weighings follow : 



Weighings op Nestling Meadowlabks 



Weight of egg ready to hatch 135 oz. 



Weight of day-old nestling 25 



Weight of eight-day-old nestling 2.50 



Weight of average adult 4.00 



Although more exfieriments are necessary to establish the 

 exact gain in weight of nestling birds, yet these experiments have 

 furnished evidence as to the enormous quantities of food con- 

 sumed by nestling birds. When one considers that there is a 

 gain of about three ounces (93.3 grams) in weight inside of two 

 weeks, and that this added weight must be calculated by the 

 weight of food consumed minus the waste thrown off in the 

 various forms of excreta and expired air, the quantity of food 

 necessary is evident. Not only is enough food needed to maintain 

 energy, but an additional amount to maintain weight increment 

 is demanded during the period of growth. Probably each young 



