Wood Turtle Ecology and Management Strategies in a Landscape Under Active Agriculture
Wood Turtle Ecology and Management Strategies in a Landscape Under Active Agriculture

Author: Shaylyn Wallace

Publisher:

Published: 2020

Total Pages: 128

ISBN-13:

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I investigated the habitat selection of wood turtles (Glyptemys insculpta) in a landscape within active agriculture and assessed the risk of agricultural practices. I tracked 23 wood turtles and recorded their habitat use versus availability on a 3rd and 4th order scale. I found that wood turtles preferred fields over the forest and that hay fields are likely an attractant to wood turtles due to high food availability and low canopy cover. Wood turtles used the hayfields during the hay harvest season, and stayed close to field edges. I monitored the movement response of wood turtles as they were approached by agricultural machinery and found that most turtles could not successfully escape the mower. My study shows that agriculture poses a high risk to wood turtles in an agricultural landscape and management strategies are necessary to prevent populations from extirpation.

Home Range and Habitat Use of Juvenile Green Turtles in a Shallow Tidal Environment
Home Range and Habitat Use of Juvenile Green Turtles in a Shallow Tidal Environment

Author: Meagan Gary

Publisher:

Published: 2017

Total Pages: 48

ISBN-13:

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The home range can be further understood by examining: (1) environmental factors that are responsible for its selection, and (2) habitat use. Green turtle (Chelonia mydas) home ranges are characterized by their food abundance, distribution, and quality. The shallow water habitats of The Bahamas are important foraging sites for juvenile green turtle. The goal of this study was to determine how turtles use their home range at a tidal foraging site. I tracked turtle home range using acoustic telemetry. I conducted esophageal lavage on tracked turtles and mapped the vegetation coverage. Turtle home ranges were small, and often overlapping areas (mean ± SD= 0.64 ± 0.24 km2). Turtles consumed primarily seagrass (Thalassia testudinum), which was concentrated inside the tidal creek. This study documented the smallest recorded home ranges of juvenile green turtles and examines the combination of the effects of tide, temperature, and vegetation on green turtle home range.

Navigating the Thermal Landscape
Navigating the Thermal Landscape

Author: Geoffrey Norman Hughes

Publisher:

Published: 2016

Total Pages:

ISBN-13:

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Thermal ecology studies of ectotherms, like turtles, have typically focused on a species' thermal preferences and tolerances, or on thermoregulation site selections; only recently have landscape-scale thermal ecology studies been performed. I examined the spatial and nesting ecology of wood turtles in Sudbury District of Ontario, Canada, in a thermal context. I also measured the thermal impacts of natural resource extraction on wood turtle habitat. Wood turtles (Glyptemys insculpta) cover a wide variety of terrestrial and aquatic habitats during their annual cycle, making them ideal for thermo-spatial studies. I tracked movements and thermal use of 15 radio-tagged adult turtles during the active season, comparing their selections to temperature monitoring stations spread in an array across the study area, to determine if the turtles are navigating a thermal landscape. Temperature had minimal influence on home range-scale movements, but possibly influenced movements at a smaller spatial scale. I compared the thermal landscape (using thermal imagery), soil moisture, and grain size distribution of 3 nesting beaches to determine the strongest predictor of nest-searching behaviour. Temperature range appeared to be an important cue, but females were apparently using a suite of cues to select their nest sites. I mapped the thermal landscapes of six sites: two relatively undisturbed wood turtle habitat sites, two recently-harvested forestry sites, and two active gravel pits, to find the effects of resource harvesting on wood turtle habitat. The undisturbed sites were cooler and less variable than the disturbed sites, and provided higher-quality thermal habitat. My results support the findings of previous studies: that temperature is a stronger driver of turtle behaviour at the micro-habitat scale than the home range scale, and that soil temperature co-varies with soil structural variables at the micro-habitat scale. The data from the habitat mapping provide useful information for conservation efforts when mitigating or rehabilitating wood turtle habitat.

Hierarchical Modeling and Inference in Ecology
Hierarchical Modeling and Inference in Ecology

Author: J. Andrew Royle

Publisher: Elsevier

Published: 2008-10-15

Total Pages: 463

ISBN-13: 0080559255

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A guide to data collection, modeling and inference strategies for biological survey data using Bayesian and classical statistical methods. This book describes a general and flexible framework for modeling and inference in ecological systems based on hierarchical models, with a strict focus on the use of probability models and parametric inference. Hierarchical models represent a paradigm shift in the application of statistics to ecological inference problems because they combine explicit models of ecological system structure or dynamics with models of how ecological systems are observed. The principles of hierarchical modeling are developed and applied to problems in population, metapopulation, community, and metacommunity systems. The book provides the first synthetic treatment of many recent methodological advances in ecological modeling and unifies disparate methods and procedures. The authors apply principles of hierarchical modeling to ecological problems, including * occurrence or occupancy models for estimating species distribution * abundance models based on many sampling protocols, including distance sampling * capture-recapture models with individual effects * spatial capture-recapture models based on camera trapping and related methods * population and metapopulation dynamic models * models of biodiversity, community structure and dynamics Wide variety of examples involving many taxa (birds, amphibians, mammals, insects, plants) Development of classical, likelihood-based procedures for inference, as well as Bayesian methods of analysis Detailed explanations describing the implementation of hierarchical models using freely available software such as R and WinBUGS Computing support in technical appendices in an online companion web site

Assessing Habitat Utilization by the Juvenile and Sub-adult Hawksbill Sea Turtles (Eretmochelys Imbricata) Along the Artificial Marine Habitat of the Cyril E. King Runway
Assessing Habitat Utilization by the Juvenile and Sub-adult Hawksbill Sea Turtles (Eretmochelys Imbricata) Along the Artificial Marine Habitat of the Cyril E. King Runway

Author: Scott Eanes

Publisher:

Published: 2016

Total Pages: 168

ISBN-13:

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"The marine habitat created by the extension of the Cyril E. King (CEK) runway on the island of St. Thomas, USVI is an artificial reef habitat that has become an important developmental area for critically endangered, juvenile and sub-adult hawksbill sea turtle. The marine runway habitat was divided into five sections (Section 1-NER-1, Section 2-NWR-2, Section 3-SWR-3, Section 4-SSR-4, and Section 5-SER-5). Benthic surveys examined two factors along the runway, composition of sessile benthic communities, and crevice size in an effort to link hawksbill turtle hourly usage of the habitat to either, or both factors. Five Vemco acoustic receivers were placed around the marine runway habitat to maximize acoustic coverage. Six hawksbill turtles were then captured and tagged acoustically with either a V13 or V16 acoustic (Vemco) tag, with two turtles being fitted with depth tags. Turtles were tracked for a maximum of 200 days to a minimum of 100 days. The calculated hourly habitat usage in examination with benthic composition and/or crevice size data shows a link between marine runway sections with the largest crevice size and the smallest turtles tagged in the study, with depth and benthic community composition results being inconclusive" -- Abstract.