1914] Bri/aiit: Economic Status of the Western Mcadotelark 441 



It does not seem fair to compare the food of a species of 

 bird of small size with that of one of large size without taking 

 into account the bird's capacity. The degree of injury or benefit 

 is largely dependent on the total amount consumed. In this 

 investigation measurements in cubic centimeters of the stomach 

 contents of a number of western meadowlarks have allowed the 

 eompiitation of the average stomach capacity. For male birds 

 this average capacity is three cubic centimeters ; for female birds 

 it is two and one-half cubic centimeters. The average capacity 

 is two and three-fourths cubic centimeters. 



This method allows of some interesting computations of the 

 capacity for good or harm of the western meadowlark. If thei"e 

 are twelve meadowlarks to the square mile, as there are in many 

 places, these birds demand over one hundred cubic centimeters 

 of food daily. This capacity, estimated in grain, means 2200 

 kernels, in grasshoppers 150 average-sized individuals, in cut- 

 worms 125 individuals, in ground-beetles 300, in ants 2500. As 

 digestion is constantly going on, much larger numbers are in 

 reality taken, as is evidenced by a count of the insects in a 

 stomach. These numbers, therefore, are not even a minimum. 



As pointed out (p. 412), the results of the experiments showed 

 that meadowlarks must completely digest a meal inside of four 

 hours. It was also found that grain takes longer to digest than 

 do insects. Thus it can be seen that the food found in the stomach 

 at any one time does not represent the total amount of food taken 

 daily, but only about a third part of that consumed daily. Owing 

 to the slower digestion of grain, the amount found in a stomach 

 must represent more nearly one-half of the daily requirement. 



Taking an average capacity of two and three-quarters cubic 

 centimeters and considering that each bird fills its stomach at 

 least three times a day, one hundred western meadowlarks must 

 consume near a liter, or about a quart of food each day. If the 

 food be grain it can be seen that the amount of destruction is 

 considerable ; if the food be insects it can be seen that meadow- 

 larks take a large daily toll of insects. The same type of com- 

 putation shows that a single western meadowlark must consume 

 six pounds of food a year. 



