The Ecology, Exploitation and Conservation of River Turtles

The Ecology, Exploitation and Conservation of River Turtles

Author: Don Moll

Publisher: Oxford University Press

Published: 2004-04-08

Total Pages: 408

ISBN-13: 0195102290

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The underlying theme of this book is that a widespread, taxonomically diverse group of animals, important both from ecological and human resource perspectives, remains poorly understood and in delcine, while receiving scant attention from the ecological and conservation community. This volume proposes a comprehensive overview of the world's river turtles' ecology, conservation, and management. It begins with a categorization of taxa which inhabit flowing water habitats followed by information on their evolutionary and physical diversity and biogeography. Within the framework of ecology, the authors discuss the composition of river turtle communities in different types of lotic habitats and regions, population dynamics, movements, reproductive characteristics and behavior, predators, and feeding relationships. In a conservation and management section, the authors identify and evaluate the nature and intensity of factors which threaten river turtle survival--almost all of which involve direct human exploitation or indirect effects of human induced habitat alteration and degradation. They then list and evaluate the various schemes which have been proposed or employed to halt declines and restore populations, and make recommendations for future management plans for specific species and regions. In closing, they state their viewpoint concerning future research directions and priorities, and an evaluation of future prospects for survival of the world's river turtle species.


Nesting Ecology in Reintroduced Alligator Snapping Turtles (Macrochelys Temminckii)

Nesting Ecology in Reintroduced Alligator Snapping Turtles (Macrochelys Temminckii)

Author: Jessica Leigh Miller

Publisher:

Published: 2012

Total Pages: 120

ISBN-13:

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The alligator snapping turtle (Macrochelys temminckii) is a large freshwater species that has experienced population declines throughout much of its range. In an effort to reestablish an extirpated population in southern Oklahoma, adult M. temminckii were released at Tishomingo National Wildlife Refuge in 2007. I investigated several aspects of M. temminckii reproductive biology within this reintroduced population, including nest-site selection, reproductive and nest predation rates, and patterns of temperature-dependent sex determination (TSD) in natural nests. Water depth two meters from the shoreline and percentage ground cover were important factors in nest-site selection. The nest predation rate was 76% when efforts were made to protect nests and the average clutch size in intact nests was 22.4 eggs. The overall sex ratio in 2010 recruits was strongly female-biased (91.8% female) and a strongly skewed population sex ratio may become a serious threat to this reintroduced population if this trend continues. I also developed a technique to reliably estimate clutch size from predated M. temminckii shell fragments which will improve estimates of mean clutch size (and therefore annual fecundity) for the population. The persistence of several adult M. temminckii and evidence of successful reproduction and recruitment are positive signs, but post-release monitoring will need to continue for several more years in order for this reintroduction to be considered a success.


Movement Patterns, Nesting Ecology, and Nest-site Selection of the Federally-listed Bog Turtle in Maryland

Movement Patterns, Nesting Ecology, and Nest-site Selection of the Federally-listed Bog Turtle in Maryland

Author: Nathan W. Byer

Publisher:

Published: 2015

Total Pages: 84

ISBN-13:

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The Bog Turtle (Glyptemys muhlenbergii) is North America's smallest and perhaps most vulnerable freshwater turtle, and very little data exists on nesting ecology and habitat use for this species. I used radio telemetry surveys of female turtles to examine movement patterns, nesting ecology, and nest site selection of Bog Turtles at two sites in Maryland. Home range sizes differed between sites, and females moved larger distances during the nesting season in mid-June. Selected nest locations were near water with low overstory vegetation cover and high sedge cover. Nest success was never above 50% at either site, and one site did not experience any nest success. Many successful nests experienced predation by small mammals or insects before hatchlings emerged. Results from this study suggest that further attention to nesting habitat requirements and nest success patterns in this species is needed, as sites may not achieve sufficient nest success for population persistence.