236 NATURE STUDY REVIEW [8 :6— Sept., 1912 



Female fed young, 177 times. 



Total, by both parents, 303 times. 



Average interval between feedings, 3 minutes. 



Excreta removed, 109 times. 



Weight of nestlings at 4:25 a. m., 91.4 grams. 



Weight of nestlings at 7 :35 p. m., 100.7 grams. 



Increase in weight, in 15 hours, 9.3 grams. 



Percentage increase in weight, 10.1. 



The day following the one on which the record was made 

 furnished opportunity to collect several of the pellets of excreta. 

 The two larger nestlings had left, hence the calculation must be 

 by so much in error. The average weight of these pellets was .2 

 of a gram. It must be noted also that these were obtained by 

 gently pressing upon the bodies of the nestlings, hence must have 

 been considerably under the average size of those expelled under 

 natural stimulus. However, the observation was frequently made 

 that the parent birds carried away masses of excreta of consider- 

 able variation in size. Assuming, however, that .2 gram repre- 

 sents the approximate weight of the excreta masses, it results in 

 the quantity of 21.8 grams, as the total removed from the nestlings 

 during the day. As previously noted, the grasses and weeds 

 shading the nest were removed or turned aside in order that 

 the nest might be more easily observed. This resulted, of course, 

 in exposing the nestlings to the direct rays of the sun. Evapora- 

 tion from their bodies, as well as the amount of water vapor in 

 the expired air, must have been considerable. There was no 

 way of determining this. The gain in weight together with the 

 weight of the excreta removed, amounts to 31.1 grams ; an amount 

 which would be greatly increased did we know the weight of 

 the water lost. It is evident that the weight of the food for the 

 period covering the observations must have been at least over 

 40 grams. 



An effort was made to obtain some of the larvae in order 

 to identify them. This did not prove practicable, since in feeding, 

 the parent birds mutilated them badly. The moths appeared to 

 be those whose larvae are cutworms and sod worms, though of 

 course, there could be no certainty with reference to their iden- 

 tification. It is noticeable that during the middle portion of the 

 day the number of moths fed was much greater than at any 

 other time. 



In the record the term canker worm is used since such are 

 popularly known to be destructive. Of these several species were 

 being fed. From what plants they were being obtained could not 



