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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Orientation in pelagic fishes. (I) Optical problems. (II) Sonic tracking,

Henderson, Herman Francis, January 1963 (has links)
Thesis (Ph. D.)--University of Wisconsin, 1963. / Vita. Bibliography: leaves 129-135.
2

Sun-compass orientation in the treefrogs, Hyla crucifer and Pseudacris triseriata triseriata

Mosher, Daniel D. January 1982 (has links)
Sun-compass orientation tests were performed on adults and larvae of the spring peeper (Hyla crucifer) and the western chorus frog (Pseudacris triseriata triseriata). All animals were tested outdoors in a circular test pool from which all visible landmarks were obscured. Response on the Y-axis varied with the life history stage, and significant interspecific differences in sun-compass orientation behavior were noted. Statistical analysis was performed with Batschelet's V-test.Adult frogs were captured as they migrated to the breeding pond and tested under sunny skies. Chorus frogs oriented on the deep-water Y-axis of the nearest shoreline (n=30, p <0.005) but spring peepers did not orient (n=42, p >0.10).Frogs were also captured in the breeding pond at weekly intervals throughout the breeding season and tested under sunny skies. Chorus frogs oriented toward shore on the Y-axis (n=45, p <0.005); spring peepers did not orient (n=96, p >0.10). Adult chorus frogs kept in outdoor enclosures for a month after the breeding season were still oriented toward shore on the Y-axis (n=6, p <0.05). Chorus frogs tested under sunny skies after ten days of constant temperature, dim-light conditions in the laboratory did not orient (n=10, p >0.10).Adult chorus frogs captured as they left the breeding pond and tested under sunny skies did not orient on the Y-axis of the nearest shoreline (n=33, p >0.10), and neither did spring peepers (n=38, p >0.10).Larval western chorus frogs raised in outdoor enclosures oriented toward deep water on the Y-axis within five days after hatching (n=29, p< 0.005) and during late premetamorphosis (n=33, p <0.001). Chorus frog larvae did not orient during mid-premetamorphosis (n=32, p >0.10). Newly metamorphosed juveniles oriented on the Y-axis toward shore within a week after emergence (n=25, p< 0.01).Larval spring peepers oriented on the Y-axis toward shore within 18 days after hatching (n=37, p <0.0001) and also late in metamorphosis (n=29, p< 0.0001). Newly metamorphosed juveniles were not tested.
3

Sun compass orientation in juvenile green sea turtles (Chelonia mydas)

Unknown Date (has links)
Recent studies show that sea turtles use both magnetic and visual cues to successfully orient. Juvenile green sea turtles from the near shore reefs of Palm Beach County, Florida were brought to the lab to determine whether the sun could serve as a visual orientation cue. When tethered during the day in a large outdoor tank west of the ocean, the turtles oriented east to northeast. To determine whether the sun's position was used to maintain their heading, I altered the turtles' perception of time by entraining them to a light cycle advanced by 7 h relative to the natural cycle. When tested afterward in the same outdoor tank the turtles oriented northwest, the predicted direction after compensating for the sun's movement over 7 h across the sky. Orientation was unchanged when the turtles bore magnets that negated the use of magnetic cues. These results are consistent with the hypothesis that the turtles used the sun for orientation. / by Cody Robert Mott. / Thesis (M.S.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.
4

Neural correlates of magnetic field detection and geomagnetic orientation by the marine mollusk Tritonia diomedea / by Kenneth John Lohmann.

Lohmann, Kenneth John, January 1988 (has links)
Thesis (Ph. D.)--University of Washington, 1988. / Vita. Bibliography: leaves [74]-79.
5

Regional differences in migratory activity by hatchling loggerhead sea turtles (Caretta caretta): effect of reciprocal nest translocations

Unknown Date (has links)
There are four distinct subpopulations of loggerhead sea turtles (Caretta caretta) in Florida as determined behaviorally by geographic fidelity, and genetically by mitochondrial haplotypes. The South Florida subpopulation consists of females nesting on the southeastern and southwestern coasts of Florida and their offspring. Previous research shows that west coast hatchlings exhibit higher levels of nocturnal swimming during the postfrenzy period than east coast hatchlings. This study attempted to determine how these differences in migratory behavior develop. A reciprocal translocation experiment was conducted to distinguish between environmental and genetic factors. No consistent differences in hatchling swimming behavior were seen based on geography. Movement of nests resulted in lower levels of nocturnal swimming behavior in hatchlings compared to hatchlings that emerged from natural nests, suggesting that the relocation of nests may not provide a natural incubation environment for developing hatchlings. / by Jeffrey Guertin. / Thesis (M.S.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.
6

Origins, movements, and foraging behavior of Hawksbill Sea Turtles (Eretmochelys imbricata) in Palm Beach County waters, Florida, USA

Unknown Date (has links)
This dissertation examined the natal origins, home-range, and in-situ foraging behavior of an aggregation of sub-adult hawksbill turtles (Eretmochelys imbricata) found off the coast of Palm Beach County, Florida. Surveys were conducted on approximately 30 linear km of reef between 15 and 30 m in depth. Tissue samples were retrieved from 112 turtles for mtDNA haplotype determination. GPS-linked satellite transmitters were deployed on six resident sub-adults, resulting in both minimum convex polygon (MCP) and 95%, 50%, and 25% kernel density estimates (KDE) of home-range size. A foraging ethogram was developed, and sequential analysis performed on thirty videos (141 total minutes) of in-situ foraging behavior. Seventeen total haplotypes were identified in this aggregation, the majority (75%) of which represented rookeries on Mexico’s Yucatan Peninsula. Other sources, from most to least important, include Barbados, Costa Rica, Puerto Rico, Antigua, and the U.S. Virgin Islands. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
7

Memory for "what", "where", and "when" information by rhesus monkeys (Macaca mulatta) and adult humans

Hoffman, Megan L. January 2007 (has links)
Thesis (M.A.)--Georgia State University, 2007. / Title from file title page. David A. Washburn, committee chair; Eric Vanman, Michael J. Beran, Heather Kleider, committee members. Electronic text (76 p. : col. ill.) : digital, PDF file. Description based on contents viewed Mar. 25, 2008. Includes bibliographical references (p. 71-76).
8

The role of air and waterborne odors in orientation and food detection in three species of marine turtles

Unknown Date (has links)
The cues used by marine turtles to locate foraging areas in the open ocean are largely unknown though some species (especially the green turtle [Chelonia mydas], the loggerhead [Caretta caretta], and the leatherback [Dermochelys coriacea]) somehow locate areas of high productivity. Loggerheads can detect airborne odors, but a capacity to orient has not yet been investigated. In this comparative study, tethered loggerheads and leatherbacks were exposed to dimethyl sulfide (DMS) or food odors in a laminar flow of air. Turtles did not orient into the air current. Free-swimming loggerheads and green turtles were also exposed to air- or waterborne food (squid) odor plus a neutral visual stimulus. Both species showed increases in swimming activity and biting behavior to both stimuli. These results suggest that airborne odors are likely not used to locate distant areas, but that they are used in localized food searching efforts. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
9

Magnetic orientation of loggerhead sea turtle hatchlings: migratory strategies in the Gulf of Mexico

Unknown Date (has links)
Loggerhead sea turtles nest on either the Atlantic or Gulf coast of Florida. The hatchlings from these nests migrate offshore in opposite directions. The purpose of my study was to determine if Gulf coast hatchlings use magnetic maps, as Atlantic coast hatchlings do, both to locate areas favorable for survival in the Gulf of Mexico and to orient appropriately within surface currents that could transport them into the Atlantic Ocean. To find out, I presented Gulf coast hatchlings with magnetic fields corresponding to different locations inside the Gulf, and within currents leading into (Florida Straits) and within (Gulf Stream) the western portion of the Atlantic Ocean. I conclude that Gulf coast hatchlings (i) use a high resolution magnetic map for navigation within the Gulf of Mexico, (ii) initially remain within the eastern Gulf, but later may (iii) gain entry into currents that transport them into Atlantic waters. / by Maria W. Merrill. / Thesis (M.S.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.
10

The hawksbill rookery at Antigua, W.I.: nest success, hatchling behavior, and hatchling survival during offshore migration

Unknown Date (has links)
The younger life history stages of marine turtles (eggs, hatchlings) often fail to survive. To compensate, sea turtles nest several times/season and produce large clutches of eggs. The hawksbill produces the largest clutches (150 eggs) and the smallest hatchlings of any marine turtle. My study, done at Jumby Bay in Antigua, West Indies, was designed to determine whether they did so to compensate for loss in the nest, hatchling loss in the water, or both factors. I found that most of the eggs (79 %) survived to become hatchlings that left the nest and entered the sea. However, 88 % of the hatchlings swimming offshore were taken by predators within minutes after they began their migration. These results suggest that at Jumby Bay, large clutch size is favored in hawksbills because of predation pressures on the hatchlings. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2013.

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