1912] Ditmars: Feeding Habits oj Serpents 227 



to feed upon mammals or birds, and of particular significance is the 

 evident restriction of the diet to snakes alone. The writer's speci- 

 mens have lived for years with various lizards running about their 

 cages, without eliciting the least interest on the part of the Cobra. 

 Moreover, the writer's experiments tend to show that other poisonous 

 snakes are seldom or never eaten. These habits are at variance with 

 other markedly cannibalistic Elapines, as the species of Flaps have 

 been noted to kill and eat small rattlesnakes, Sistrurus, while they 

 often feed upon the smaller lizards of the Scincidae and Iguanid.ae 



Following are notes involving the feeding of Naja bungarus: 



To test the assertion that N. bungarus feeds but seldom upon the 

 Viperine snakes, possibly possessing an instinctive dread of the deep 

 wounds liable to be inflicted by the fangs of such reptiles, the follow- 

 ing experiment was conducted. 



A large, thick-bodied, harmless w^ater snake {Tropidonotus 

 taxispilotus), and a poisonous water moccasin {Ancisircdon pisci- 

 vorus), of much the same proportions, were selected for the experi- 

 ment during a period when the big cobra was voraciously awaiting 

 its weekly meal of a living snake. The door of the cage was rolled 

 back, and the poisonous snake thrown inside. The cobra made the 

 customary rush for the food, but upon reaching the snake paused 

 abruptly. 



This was the first time in the feeding of this king cobra in our 

 Reptile House that he failed to immediately seize his victim and begin 

 to swallow it. The moccasin was permitted to remain in the cage 

 for about five minutes, during which time the cobra reared slightly 

 from the door, and regarded it intently. To ascertain whether the 

 cobra was hungry, a common striped snake was placed in the cage. 

 It was grasped and swallowed without hesitation. 



The moccasin was again introduced. There was the same rush, 

 and the same careful examination of the newcomer. This time, 

 annoyed by the unceremonious treatment it had received, the pit- 

 viper showed fight. Upon this display of hostility the cobra backed 

 off hurriedly, nervously dilating its hood, and rearing upward. The 

 moccasin was finally removed unharmed, and the large, harmless 

 water snake was quietly placed in the cage. To the human observer 

 it matched the moccasin closely, and made a show of temper consid- 

 erably more emphatic than the former, but the cobra attacked it 

 without an instant's hesitation and soon swallowed it. This experi- 



