CHEMICAL COMMUNICATION IN THE IGUANID LIZARD SCELOPORUS JARROVI.
Item
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Title
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CHEMICAL COMMUNICATION IN THE IGUANID LIZARD SCELOPORUS JARROVI.
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Identifier
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AAI8203284
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identifier
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8203284
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Creator
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GRAVELLE, KAREN.
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Contributor
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Prof. Carol A. Simon
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Date
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1981
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Language
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English
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Publisher
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City University of New York.
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Subject
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Psychology, Psychobiology
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Abstract
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Considerable anecdotal evidence and a few recent quantitative studies suggest that lizards may utilize chemical signals in communicating to conspecifics. This hypothesis was examined in a series of three experiments using an iguanid lizard, Sceloporus jarrovi.;In each experiment, resident S. jarrovi of different sex/age classes were placed in three out of four similar pens of an outdoor enclosure approximating their natural habitat. The fourth pen was left empty. After residing in these pens for a period of time sufficient to permit them an opportunity to mark these areas with chemical deposits, the residents were removed. Experimental subjects were then individually introduced to the empty enclosure and permitted unrestricted access to all four pens. The responses of the experimental subjects to the four pens were compared to those of control subjects tested prior to the placing of the resident animals in the enclosure. Significant differences between the experimental and control groups indicated that resident animals had deposited chemicals which were detected and responded to by experimental subjects.;The results indicate that breeding males can detect differences between the chemicals deposited by an adult female, an adult male, and a juvenile male and that they are attracted to an area containing the chemical deposits of the female. The number of tongue extrusions performed by experimental males as compared to controls increased in the pen inhabited by the adult female and decreased in the adult male's pen. Experimental males showed a significant increase over controls in two behaviors, defecating and pelvic rubbing, which could be involved in depositing chemicals, with the increase in pelvic rubs occurring only in the pen housing the adult female.;Breeding males also appeared to be able to discriminate, although with more difficulty, between the deposits of adult and juvenile females and to be attracted to the area containing the deposits of the adult female. The number of tongue extrusions performed by experimental males increased significantly in the adult female's pen but not in the pens housing the juvenile females. Experimental males again performed significantly more pelvic rubs than did controls. However, while an increase occurred in both the pen housing the adult female and the pen housing the single juvenile female, only the latter was significant.;Adult males tested during non-breeding months showed no differential responses to the chemicals of an adult female, an adult male, and a juvenile male. In contrast to the relatively high rate of pelvic rubbing demonstrated in both experiments conducted during the breeding season, none of the males performed pelvic rubs when not in breeding condition.;Adult females tested in both the breeding and non-breeding seasons showed no significant response to the chemical deposits of conspecifics (an adult female, an adult male, and a juvenile male). In addition, females rarely performed pelvic rubs during either breeding or non-breeding months.;The fact that pelvic rubs were performed only by males in breeding condition suggests that the sexually dimorphic femoral pores present in S. jarrovi may be one source of the chemical signals deposited by males, although substances from the cloacal region could also be deposited by rubbing the pelvis against the substrate. While the response of males to the four pens indicates that adult females deposit chemicals which function in mating, the data shed no light on the source of these chemicals or on how they are deposited.;Finally, there was no evidence that S. jarrovi respond to the deposits of conspecifics with visual displays.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
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Program
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Psychology
