Literaturdatenbank
Literaturdatenbank |
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Davis, M. (1981). Aspects of the social and spatial experience of eastern box turtles terrapene carolina carolina. Unpublished thesis , University of Tennessee, Knoxville.
Added by: Sarina Wunderlich (12 Dec 2010 20:43:03 UTC) |
| Resource type: Thesis/Dissertation BibTeX citation key: Davis1981 View all bibliographic details  |
Categories: General Keywords: Schildkröten = turtles + tortoises, Verhalten = ethology Creators: Davis Publisher: University of Tennessee (Knoxville) |
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| Abstract |
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An investigation of the ways in which eastern box turtles experience their social and spatial environment was conducted using an ethological approach in combination with a phenomenological orientation. The primary question of what the turtles experienced was addressed by determining wh at they could discriminate. Discrimination between other individuals and between areas of space was investigated. The inquiry was extended to investigate the quality of this experience by assessing the functional significance of the cues and behavior patterns involved in such discriminations. The approach was to observe behavior in relation to its context in a combination of naturalistic, seminaturalistic, and laboratory settings. Discrimination of spatial areas was studied in the field by repeatedly locating turtles through the use of telemetry. Most turtles were found to use only prescribed areas within the larger area of suitable habitat. Difficulties in unobtrusively observing the turtles in the field made it impossible to assess directly the basis of this discrimination. Direct observations of turtles' movements and more detailed information about their locations were obtained from turtles introduced into an outdoor enclosure. The turtles showed significant individual preferences for different areas of the enclosure, indicating their ability to discriminate among such areas. The resident turtles were subsequently removed from the enclosure while new shelter sites were installed. A new group of turtles was then introduced into the enclosure simultaneously with the reintroduction of the residents. A significant difference in use of resting sites by new and resident turtles was obtained, with more of the new turt1es using the new shelter sites and more of the previous residents using previous1y established sites. The turtles also showed overall patterns of area use: they tended to move along the perimeter and to rest in corner locations, suggesting certain cues which they p1ausibly might have used to guide their movements. The functiona1 significance of two such potential cues, darkness and slope, was investigated by presenting them to hatchling box turt1es under control1ed 1aboratory conditions. The turt1es moved significant1y mor-e often to a dark rather than a 1 i ght wall of achamber, regard1 ess of color, and showed a tendency to move uphil1 rather than downhi11. This suggests that darkness may be experienced as attractive by the turt1es even in the absence of other factors which wou1d frequent1y accompany it in the natural habitat. The turt1es' experience of other turt1es was investigated by addressing the basic question of recognition of other individuals, or classes of individuals, within a spatia1 context. Proxemic studies of turt1es in an outdoor enc10sure and of hatch1ings housed indoors demonstrated that in both settings turtles who touched each other were significantly more likely to be found together again than those who were found c10se together but not touching. Discrimination between neighbors and strangers was investigated in two parallel studies. One tested wild-caught "neighbors," (trapped near each other) vs. "strangers," (found farther apart); the other tested hatch1ings housed together vs. separate1y. Turt1es discriminated between neighbors and strangers by disp1aying higher levels of agonistic and investigatory behavior toward strangers, with some of these differences attaining statistical significance. This study progressed beyond the basic issue of neighbor recognition to an investigation of the meaning of certain potentially communicative gestures. The existence of individual styles of interacting was investigated by comparing the behavior of turtles across contexts. A hierarchal pattern of feeding success was obtained within groups of hatchlings. Hatchlings who were more successful in feeding competition were found to react less to human contact. Wild turtles who reacted with less head retraction and movement to human approach and contact traversed greater distances per day in the field, thus suggesting the presence of individual styles of experiencing both the social and spatial environment.
Added by: Sarina Wunderlich |