All ETDs from UAB

Advisory Committee Chair

Thane R Wibbels

Advisory Committee Members

Peter H Dutton

Ken R Marion

David W Owens

Robert W Thacker

Manjula Tiwari

Document Type

Dissertation

Date of Award

2014

Degree Name by School

Doctor of Philosophy (PhD) College of Arts and Sciences

Abstract

Leatherbacks declined significantly worldwide during the 20th century and continue to decline in the Pacific and Indian oceans. In the Pacific Ocean, nesting numbers on beaches in Malaysia and the Pacific coast of Mexico and Costa Rica have collapsed. The nesting beaches at Bird's Head Papua Barat, Indonesia, represent the last stronghold for leatherback nesting in the western Pacific. The studies in this dissertation provide basic information that is critical to our understanding of the biology, ecology, and conservation of the western Pacific leatherback. (1) Year-round nesting surveys were conducted from 2005 to 2011 at both Jamursba Medi and Wermon beaches to obtain robust estimates of the nesting population size. The overall Bird's Head leatherback population has declined at an approximate rate of 5.9% per year and has been reduced to approximately 500 females nesting annually in 2011. (2). The primary threats adversely impacting hatchling production were evaluated and quantified within experimental beach plots from 2005-2013. The primary threats were predation, tidal inundation, beach erosion, and extreme beach temperatures, all of which adversely affected nest survival, hatching success, and subsequently hatchling production. (3) Beach and nest temperatures were evaluated relative to their impact on hatchling sex ratios and hatching success. The beach temperature profiles throughout boreal summer varied between the three beaches at Jamursba Medi and during austral summer at Wermon. Overall, mean beach temperatures were typically near or above the pivotal temperature for most of the nesting seasons from 2005-2013, thus suggesting female-biased hatchling sex ratios may predominate. Mean daily sand temperatures were relatively high at specific beach and beach plots, potentially lowering hatching success. (4) Finally, a science-based beach management plan was generated to optimize hatchling production from nesting beaches at Bird's Head. This plan includes specific actions that address the primary threats limiting hatchling production, including predator control, nest protection, and nest relocation. The plan also integrates community participation and conservation partnerships with government and NGO entities in the form of collaborative forum for ensuring long-term stability of the leatherback conservation program at Bird's Head nesting beaches.

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