Research Library | Digital Repository

Field study of the social behavior of the black lizard, Ctenosaura pectinata. American Museum novitates ; no. 1493

Show simple item record Evans, Llewellyn Thomas. en_US 2005-10-06T17:31:18Z 2005-10-06T17:31:18Z 1951 en_US
dc.description 26 p. : ill. ; 24 cm. en_US
dc.description Includes bibliographical references (p. 24-26). en_US
dc.description.abstract "A colony of 22 lizards (Ctenosaura pectinata) was located on the loose-rock wall of a cemetery near the village of Acapancingo, near Cuernavaca, Morelos, Mexico. This colony was studied during the late winter and spring. Animals were identified by such distinguishing marks as broken or regenerated tails, specific markings of the neck, the degree of blackness of the skin, and by individual behavioral traits. Each tended to remain on or in the vicinity of a particular rock, usually one located slightly higher than others along the wall. These sunning or lookout stones were between 15 and 30 feet apart. Three of the females shared sunning rocks with their mates, while two females occupied separate points along the wall. Among the adult males a hierarchy, which comprised at least eight individuals, was found to exist. The highest ranking male preëmpted the right to trespass upon the footage of any other male that dwelled upon the wall. If he encountered any sign of opposition as he crossed a territorial boundary he merely opened his jaws threateningly and passed on while his lesser rivals crawled down into the crevices until he had passed. The 'tyrant's' nearest neighbors on the wall possessed the same right of trespass but to a very much more limited degree. They never passed over the 'tyrant's' holding, which was located at the highest point of the wall, at the north corner, even though it was closest to the food supply. All members of the colony fed, unmolested by the 'tyrant,' upon bean seedlings in the near-by field and drank from the near-by stream. Each individual actually possessed no more 'territory' than the narrow strip of wall that extended halfway between his lookout rock and that of his neighbors on either side of him. This small footage was defended against encroachment by all except the 'tyrant' himself, and on rare occasions by a male who held a footage on the wall next to that of the 'tyrant.' All lesser males in the hierarchy respected one another's territorial rights and were never observed to trespass. It is believed that this colony type of lizard society evolved from the simple individual territoriality, which is still prevalent in C. pectinata that occur far from tilled soil. The daily 'tour of inspection' that the 'tyrant' makes along the walls of the cemetery represents a vestige of the habit that black iguanas, like most lizards that live in non-agricultural regions, have of patrolling their individual territories, each of which would be greater in area than the entire bean field and cemetery combined. With the advent of agriculture in Mexico many centuries ago, the concentration of succulent food in small fields surrounded by loose stone walls provided ideal ecological conditions for large herbivorous lizards such as those of the genus Ctenosaura. Such an environment may have resulted in adaptive behavioral changes, especially on the part of low-ranking individuals in the group. This is indicated by the fact that, although all eight males in the hierarchy exhibited varying degrees of pugnacity during the period of observation, only male A regularly threatened the others and preëmpted the right of at least temporary trespass on their resting areas. By yielding to male A, the lesser members of the hierarchy gained the unusual security of the rock walls as dwelling places and enjoyed the bountiful food to be found in the gardens. In untilled areas no colonies were observed; instead, individuals were widely dispersed, and no hierarchy was possible. Rivals no doubt fought for a territory, but the defeated animal simply moved on in search of another area"--P. 23-24. en_US
dc.format.extent 8047033 bytes
dc.format.mimetype application/pdf
dc.language eng en_US
dc.language.iso en_US
dc.publisher New York : American Museum of Natural History en_US
dc.relation.ispartofseries American Museum novitates ; no. 1493 en_US
dc.subject.lcc QL1 .A436 no.1493, 1951 en_US
dc.subject.lcsh Ctenosaura pectinata -- Behavior. en_US
dc.subject.lcsh Social behavior in animals. en_US
dc.subject.lcsh Iguanas -- Behavior. en_US
dc.subject.lcsh Lizards -- Behavior -- Mexico -- Cuernavaca Region. en_US
dc.subject.lcsh Lizards -- Behavior. en_US
dc.subject.lcsh Reptiles -- Behavior -- Mexico -- Cuernavaca Region. en_US
dc.subject.lcsh Reptiles -- Behavior. en_US
dc.subject.lcsh Lizards -- Mexico -- Cuernavaca Region. en_US
dc.subject.lcsh Reptiles -- Mexico -- Cuernavaca Region. en_US
dc.title Field study of the social behavior of the black lizard, Ctenosaura pectinata. American Museum novitates ; no. 1493 en_US
dc.title.alternative Social behavior of the black lizard en_US
dc.type text en_US

Files in this item

This item appears in the following Collection(s)

  • American Museum Novitates
    Novitates (Latin for "new acquaintances"), published continuously and numbered consecutively since 1921, are short papers that contain descriptions of new forms and reports in zoology, paleontology, and geology. New numbers are published at irregular intervals.

Show simple item record

Search Entire Repository

Advanced Search


My Account