42 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 122 



the ground or dangle in midair for a moment. Alternately, one lizard 

 may attempt to escape, opening his mouth and scratching with a 

 front foot at the other's snout. This wrestling with locked jaws may 

 last for several minutes and may be repeated two or three times. 

 Usually one of these encounters is decisive and the loser retreats 

 immediately after the bout. I have never seen a defeated lizard so 

 injured or exhausted that it was unable to run away. 



Damage sometimes results from these bouts and blood is drawn, 

 though the wounds are restricted to the snout. Some males are 

 found with a swelling on one of the mandibles, probably wounds from 

 this sort of combat that have become infected. (Schmidt, 1928, 

 suggested the same thing for A. cristatellus in Puerto Rico.) The 

 infected wounds apparently are painfid. One noosed male with an 

 infected jaw repeatedly bit and released my finger rather than biting 

 and holding as a male normally does. 



The preceding descriptions of display provide a foundation for 

 discussing the role that social behavior plays in the spatial organization 

 of A. lineatopus. Two sorts of social behavior seem unportant: 

 courtship and agonistic behavior. 



Courtship. — This behavior brings together male and female when 

 they are ready to copulate. Evidence suggests that it also influences 

 males and females to establish and maintain overlapping activity 

 ranges and in effect to form pair bonds. 



This pattern, a male with a home range shared by one or several 

 females that are his mates, is common among vertebrates. It is 

 perhaps most common among bu'ds and mammals in which the male 

 and female share in care of the young. It seems widespread in lizards, 

 particularly iguanids (Anolis sagrei, Evans, 1938a, Oliver, 1948; 

 Sceloporus olivaceous, Blair, 1960; Uta stansburiana, Tinkle, et al, 1962; 

 Basiliscus vittatus, Ilirth, 1963a; and Agama agama, Harris, 1964). 

 The role of courtship in establishing this pattern is far from clear. 

 Blair (1960) feels that the males of Sceloporus olivaceous seek out the 

 females. In Agama agama, Harris (1964) has evidence that it is the 

 females that make the choice, joining a male that has established a 

 home range. Hunsaker (1962) showed experimentally that in the 

 Sceloporus torqiiatus group it was the male bobbing display that was 

 attractive to females, and Hunsaker suggested that this influenced 

 them to settle near the male. Perhaps dewlap displays of the adult 

 male A. lineatopus are similarly attractive to females. 



Though the male A. lineatopus spends a considerable amount of 

 time chasing and bobbing and dewlapping to females, I observed 

 copulations infrequently. Chases, though frequent, are seldom per- 

 sistent, and I never saw a male catch a female that was trying to 

 avoid him. 



