Recipient of the 2015 Outstanding Master's Thesis Award - First Place.
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Open Access Thesis
Wood turtle--Ecology--Iowa--Black Hawk County, Wood turtle--Ecology--Iowa--Butler County, Electronic Theses and Dissertations, ETD
Population structure, population size, and the thermal ecology of wood turtles (Glyptemys insculpta) was studied in a suburban population in Black Hawk County (BHC) and compared to a rural population in Butler County (BC), Iowa. In a suburban population of 35 wood turtles, 32 (91.4%) were adults distributed in a 1:1 sex ratio [16 (45.7%) females and 16 (45.7%) males], and 3 (8.6%) were juveniles. In the rural population, 60 (98.4% of the total population) adult turtles were distributed in a 3:2 sex ratio [36 (59.0%) females and 24 (39.3%) males], and one (1.7%) juvenile was located. Population structure was similar at both study sites and indicates that these populations consist of older adults with low numbers of juveniles. Thermal and ecological data were analyzed by population (study site), individual turtle, sex, and by activity period (Hibernation, Prenesting, Nesting, Postnesting, and Prehibernation). Between populations, mean annual body temperature was significantly greater among females when comparing BC 2004 data to BHC 2012 data. Males in BC had significantly higher annual mean body temperature when comparing both BC data from 2004 and 2005 to BHC 2012 data. Annual mean turtle percent exposure (PE) was only significantly different analyzed between populations: annual mean PE of females in BC during 2004 and 2005 was significantly greater than that of females in BHC during 2012. Similarly, males in BC had significantly greater annual mean PE in 2004 and 2005 compared to males in BHC during 2012. During active periods, behavior differed between populations; BHC turtles were hiding in water (females: 47.8%; males: 64.2%) more often compared to BC turtles (females: 19.7%; males: 16.0%). Female wood turtles in BC basked on land more frequently (27.2%) than BHC turtles (11.0%). In BHC, wood turtles (females: 14.5%; males: 12.6%) were observed hiding on land more frequently than BC turtles (females: 7.0%; males: 2.5%). Wood turtles in BHC display altered patterns of habitat usage and behavior compared to wood turtles in BC. This is perhaps due to differences in site physiography and levels of human impact, and ultimately manifests in altered thermal environments at each site.
Date of Award
Master of Science
Department of Biology
Jeffrey W. Tamplin
1 PDF file (xiv, 169 pages)
2014 - Samuel Wesley Berg
Berg, Samuel Wesley, "Population structure, size, and the thermal ecology of Iowa wood turtles (Glyptemys insculpta): A comparison between suburban and rural populations" (2014). Electronic Theses and Dissertations. 65.