Migratory and reproductive behavior of the Olive Ridley Turtle, Lepidochelys olivacea (Eschscholtz, 1829), in the eastern Pacific Ocean /
Arribadas at Nancite Beach, Costa Rica most often occurred
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| Format: | Thesis Book |
| Language: | English |
| Published: |
[Place of publication not identified] :
[publisher not identified] ;
1994.
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| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=741966001&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Arribadas at Nancite Beach, Costa Rica most often occurred between the last quarter moon and the new moon. Excessive rainfall appeared to mask, erase, or otherwise negate the cues that trigger an arribada and resulted in a delayed synchronous nesting emergence. Results from telemetry indicate that females who were spatially associated during arribadas on Nancite Beach did not remain associated in the Gulf of Papagayo during the inter-nesting period, but may re- associate on Nancite Beach during subsequent arribadas. This suggests that females are independently attracted to the beach and that environmental physiological cues experienced by individuals serve to trigger responses that result in their assembly. Females departed the Gulf of Papagayo after oviposition of one or two clutches when their ovaries were depleted and serum testosterone levels were reduced. Males used the Gulf of Papagayo as a breeding area until September when the largest arribadas commenced. Females spatially associated during arribadas on Nancite Beach did not remain spatially associated during post-nesting migrations. Similarly, males captured at the Gulf of Papagayo breeding area were not spatially associated during post-breeding migrations. The turtles were notably oceanic in their migrations which spanned thousands of km, as far north as Mexico and south to Peru. The slow swimming speeds, continual movements, tendency to spend short periods of time in an area before moving elsewhere, and lack of migratory corridors leading towards common feeding areas characterize L. olives as a nomadic migrant. Lepidochelys olivacea occupied areas where upwelling was prevalent. Changes in the areas occupied by L. olives during 1 990-1 991 and 1 991-1 992 suggest that the El NifioSouthern Oscillation influences their distribution. The diving behavior of the turtles corresponded well with their reproductive and migratory behaviors and with the water depth of their habitat. Females were relatively inactive during the inter-nesting period, while males were very active during the breeding period. Female and male dive behavior changed after the breeding season when they migrated to deep oceanic waters and spent significantly more time at the surface. |
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| Item Description: | Vita. "Major Subject: Zoology". |
| Physical Description: | xiv, 241 leaves : illustrations, maps ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references. |