Habitat Selection Of Hatchling Eastern Box Turtles Terrapene Carolina Carolina Including Relevant Ecological Information

Author : Austin C. Hulbert
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (141 download)

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Download or read book Threatened Turtle Species in Ohio and Michigan written by Austin C. Hulbert and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Conservation efforts are urgently needed to reduce global biodiversity loss and to keep natural ecosystems intact. Turtles (Order Testudines) are important components of their ecosystems but are one of the most threatened vertebrate groups in the world due to habitat destruction, overexploitation, climate change, invasive species, and disease. To effectively conserve turtles, we need a detailed understanding of their spatial and population ecology, knowledge which is lacking for many declining species. Advancing technological methods are allowing researchers to address these research needs. One technological advancement is the reduction in battery size, which now allows researchers to attach miniature radio transmitters to hatchling and juvenile turtles and track them in their natural habitat. The ability to radio-track the early life stages of turtles allows researchers to study their survival, movements, and habitat needs, which are severely understudied compared to the adult life stages. Battery size reduction also allows for smaller GPS devices which automatically record locations, and which substantially reduces the time and labor required to physically locate individual animals. With this size reduction, researchers have started deploying GPS devices on small turtles; however, this method is in its early stages and requires assessment of its accuracy. Here, I used miniature radio transmitters to study the survival and dispersal of the hatchling stage of two threatened turtle species, the spotted turtle (Clemmys guttata) and Eastern box turtle (Terrapene carolina carolina), in oak savanna habitat of the Upper Midwest. I found hatchlings survival rates of both species from nest emergence through overwintering. Box turtle hatchling survival increased with less nest shade cover, which is associated with warmer nests, shorter incubation durations, and earlier nest emergence dates. Therefore, it is important for managers to maintain a range of ground cover microhabitats in nesting areas so turtles can match nest incubation conditions with current local conditions, while also maximizing hatchling survival. Additionally, I deployed GPS devices on adult spotted and Eastern box turtles to assess the reliability and accuracy of automatically recorded locations on small turtles across a range of habitat types. I found mixed support for habitat affecting accuracy of locations, but the number of satellites received and HDOP had large effects on accuracy of locations recorded by GPS devices. After screening locations based on number of satellites and HDOP, location accuracy was greatly increased. GPS devices are unlikely to be accurate for small, semi-aquatic turtle species but show promise for small, terrestrial turtle species. However, proper testing of GPS devices and methods of filtering their location data are needed to demonstrate their effectiveness when deployed on small turtle species, because unfiltered data can cause bias in ecological calculations, such as home range sizes. Overall, through the use of advancing technologies to track turtles, my research provides rare ecological data on hatchlings of threatened turtle species in the Oak Openings region, while also quantifying the effectiveness of GPS devices on these species.