EXPERIMENTS ON PROTECTIVE COLORATION 479 



SERIES VII AND VIII 



Series VII and VIII were conducted simultaneously and the 

 birds (kingbird — Tyrannus tyrannus and grackle — ^Quiscalus 

 quiscula anaeus) confined in the same cage. ^"^ The kingbird 

 was taken from the nest before learning to fly while the grackle 

 was an adult which flew into a building and was caught there. 

 In Series VII the latter bird was employed as the preyer, and 

 in Series VIII the former. In each series several different species 

 of insects (as recorded for the individual experiments) were used 

 as prey. Different backgrounds (the character of which and 

 the relative contrasts between them and the insects placed thereon 

 being noted in each experiment) were prepared at one end of 

 the cage, while the birds were perched at the opposite end, 

 care being taken in each case to avoid attracting the attention 

 of the birds more to one background than to the other while 

 the prey was being placed upon them. The insects in each 

 case were killed before being placed in position. 



Experiment 1. Figures 33 and 37. Five Melanoplus'^ were placed 

 on hay and five on sand. In fifteen minutes the grackle dropped to 

 the ground and walked to the hay from which four grasshoppers were 

 taken followed by four from the sand. The contrast l^etween the 

 grasshoppers and the sand was greater than that between them and 

 the hay, but their resemblance to the latter background was not very 

 great. The bird seemed afraid of those on the sand, drawing back 

 in apparent alarm after seizing one. 



Experiment 2. Figures 25 and 44- One Gryllus pennsylvanicus 

 was placed on sand and one on moist earth. The former combination 

 presented the greater contrast, but a little sand accidentally mixed 

 with the earth reduced the resemblance l^etween the cricket and the 

 latter liackground. After three minutes the grackle flew over the back- 

 grounds twice, apparently taking no notice of either cricket. Five 

 minutc^s later it alighted nearer the earth background, from which it 

 took the cricket. 



Experiment 3. Same as Experiment 2. In one minute the grackle 

 flew to the ground alighting nearer the cricket on the earth, which 

 was taken one minute later. 



Experiment 4- Figures 37 and 50. One Melanoplus was placed on 

 grass and one on sand. The contrast here was greater in the latter 

 than in the former combination. The grackle immediately dropped 



2^ 3.6 X 1.8 X 1.6 m. in size. 



