Browsing by Subject "nesting"
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Item Characterization of Sea Turtle Nesting on the Upper Texas Coast(2014-05-06) Hughes, Christi LynnNearly annual record Kemp?s ridley sea turtle (Lepidochelys kempii) nesting activity on the upper Texas coast (UTC; defined as beaches from Sabine Pass to Matagorda Peninsula), where scientifically verifiable nesting commenced in 2002, has occurred concurrently with recent exponential increases in the nesting population of this critically endangered species. Increased likelihood for anthropogenic interaction with this growing assemblage of UTC nesters mandated documentation of nesting activity on rapidly developing UTC beaches and characterization of in-water movements of mature conspecifics. Standardized sea turtle nesting patrols implemented on the beaches of Bolivar Peninsula, Galveston Island, and Follets Island to quantify nesting activity, as well as associated beach habitat assessments, identified major deterrents to sea turtle reproductive success and established a scientific baseline necessary for resource managers to facilitate the perpetuation of nesting activity. During 2007-2009, weekday ATV and pedestrian patrols of stated beaches during nesting season (1 April ? 15 July) aided the documentation of 15-16 UTC Kemp?s ridley nests annually. Nests were predominantly located on patrolled beaches and represented 8-12% of Texas? annual statewide nesting total. Mean emergence success rate for four clutches incubated in-situ was 91.8%. Eight nesting females intercepted on UTC beaches, as well as a rehabilitated adult male, were satellite tagged. Spatially- and/or temporally-restricted usage of breeding, internesting, migratory, and/or foraging areas in the northern Gulf of Mexico was identified and warrants further examination to facilitate the implementation of conservation initiatives designed to mitigate associated consequential mortality factors. Female internesting period movements were primarily confined to nearshore waters between Galveston and Matagorda Bays, while post-nesting movements in waters <83 m in depth ranged from Texas to the Florida Keys. Male movements near UTC beaches one year post-release were potentially indicative of breeding. Three years of subsequent monitoring indicated this male established long-term seasonal residency on offshore Louisiana foraging grounds. Nesting and telemetry data indicate the UTC is becoming increasingly important to the Kemp?s ridley population. However, current regulations do not support the sustainment of the UTC nesting cohort. Management recommendations to simultaneously foster UTC nesting and promote the continued recovery of the Kemp?s ridley sea turtle are provided herein.Item Reproductive Success of Nesting Terns and Black Skimmers on the Central Texas Coast(2013-12-12) Fern, RachelReproductive Success of Nesting Terns and Black Skimmers on the Central Texas Coast (October, 2013) Rachel R. Fern, B.S., Texas State University M.S., Texas A&M University-Corpus Christi Chair of Advisory Committee: Dr. Kim Withers Seabirds are top predators at sea and are particularly sensitive to changes in the marine environment. This gives them significant potential as bioindicators of the current state of and shifts in marine ecosystems. Nest site selection is important because the demands of reproduction can be substantial and the reproducing pair is often confined to the area selected for the duration of the breeding season. Location of the nest in relation to vegetative cover, colony density and richness can strongly influence reproductive success via exposure to predators or weather events and competition for food resources and optimal nest sites. Additionally, the timing of nesting in the breeding season can influence the outcome of the breeding effort due to storm events and increasing ambient temperatures. This study defines temporal effects and correlations between reproductive success of nesting terns and skimmers and environmental characteristics of the nest site: area (ha), vegetative coverage, Spartina spp. coverage, elevation, nest density, assemblage richness and human disturbance. The four species included in this research (Forster?s Tern Sterna forsteri, Gull-billed Tern Gelochelidon nilotica, Least Tern Sternula antillarum and Black Skimmer Rhynchops niger) were monitored at various nesting sites during the 2012 and 2013 breeding seasons. Reproductive success of Forster?s Terns seemed to be influenced by human disturbance, nest density and species richness of the nest site. Elevation and Spartina spp. coverage both positively influenced the success of Least Terns. The nesting success of Gull-billed Terns was positively correlated with elevation and species richness of the nest site, and success of Black Skimmers was negatively correlated with species richness and positively correlated with elevation. All species that nested early in the breeding season suffered nest failure due to storm events; however, Gull-billed Terns were only marginally impacted. Establishing these correlations in environmental nest site characteristics and reproductive success of nesting terns and skimmers provides a baseline understanding of tern and skimmer breeding biology in the central Coastal Bend region of Texas, which may assist future management decisions and restoration efforts.