Clutches of eggs wore collected from nesting loggerhead sea turtles (Caretta caretta caretta) on Merritt Island, Florida, during June - August 1977. Of these, 46 clutches were selected for experimentation to determine the extent to which certain factors affect hatching success. Twelve clutches were divided into subsamples which were incubated in sand maintained at 0, 25, 50, 75, and 100% moisture. Another twelve clutches were divided into subsamples and incubated in sand kept moist with the following percentages of seawater: 0 (distilled water), 25, 50, 75, and 100%; subsamples from four other clutches were subjected to the effects of one tidal inundation. Eggs from four of the clutches used in the moisture and salinity experiments were monitored for changes in size. Fifteen clutches were divided into subsamples which were kept in incubators maintained at 20, 24, 27, 30, 32, 35, and 38°C; subsamples from seven of these clutches were moved from unfavorable to optimal temperatures to study their ability to recover from stress. Three clutches were selected for an experiment to determine the effects of handling on hatching success; the following year, another five clutches were used for similar studies. Some of the hatchling turtles produced in this project were abnormal, and these were discussed in depth. From the experiments, it was determined that 25% moisture, 0-25% seawater, and 27°C produced the maximum percent hatch. The effects of handling on hatching success depended variably on the time and manner of handling. The optimum values indicated in the experiments closely approximated values for moisture, salinity, and temperature obtained from natural turtle nests on the beach.

The impact of agricultural practices on wood turtle (Glyptemys insculpta) movements and survivorship was investigated in a fragmented agri-forest landscape over two years. Agricultural activities and machinery contributed to the death of 20% of radio-tracked turtles. Annual survivorship of adults was 0.904 and 0.868 and for juveniles it was 0.815 and 0.831 for 1998 and 1999, respectively. Mutilation rates in adults were 90% +/- 3% in both years; in contrast, the maximum rate in juveniles was 57%. Setting the cutting height of disc mowers to 100 mm would increase harvest yields, reduce wear on machinery, decrease soil erosion, and reduce turtle mortality and mutilation rates. The concepts of integral, statistical, and linear range are introduced as distinct estimators of turtle movements. Since integral ranges include all habitats critical to survival, they provide an important contribution to our knowledge of imperiled species. Statistical ranges are stable and easily promote within and between study comparisons. Linear ranges quantify migratory and ranging movements. Thread-trailing techniques were used to record the fine-scale movements of six adult male G. insculpta translocated to an experimental hayfield patch-matrix. Although patch size had no effect on move length or path sinuosity, habitat structure did. Paths were generally straighter and move length longer in the harvested portion of a hayfield. Apparent habitat boundaries were shown to be permeable. Subjects exhibit three movement phases: agitation dispersal, local search, and ranging. Thus, G. insculpta exhibit predetermined movement patterns and move to maximize the likelihood of locating resources, while minimizing the probability of revisiting previously searched areas. Recent changes in agricultural practices and machinery are having a decidedly negative impact on G. insculpta. This study provides new insights into the movements of G. insculpta. Such knowledge will be an es

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<p>Understanding and adequately protecting habitat is at the forefront of modern conservation concerns. Turtles are especially vulnerable to habitat loss, and are therefore a top priority for habitat research. To help meet this need, I used radio telemetry to collect microhabitat data from two imperiled species of turtles that occupy a military base in Michigan. Preliminary data exploration was carried out with principal components analysis (PCA). Microhabitat use was then modeled for each species using conditional logistic regression (CLR), with a generalized estimating equation (GEE) element to limit bias due to individual variation. Finally, I compared habitat use between sympatric Blanding’s and Wood Turtles using Mann-Whitney U tests and Mood’s median tests to investigate the degree of overlap in microhabitat use when these species occur in sympatry. Evidence for microhabitat selection in Blanding’s Turtles was weak, suggesting that they likely do not make habitat decisions at this level. Wood Turtles selected sites that were farther from water and had fewer trees, less overstory canopy cover, and more ground cover. Additionally, the two species differed in several aspects of microhabitat use; Wood Turtles were more terrestrial and more tolerant of tree cover than Blanding’s Turtles. Patterns of microhabitat use found in this study match previously observed behavior of turtles in high quality habitat, suggesting that managers should work to maintain the habitat currently available at Camp Grayling. Additionally, because both turtle species were associated with open canopy, selective logging could benefit turtles provided care is given to timing and methods. </p>

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Although sexual stereotypes paint males as being promiscuous and females as being choosy in order to increase their reproductive success, multiple mating by females is widespread and females of many taxa often produce progeny sired by multiple males – but why? In species in which there are no direct benefits associated with mating, females may adopt promiscuous mating strategies to increase their fitness through the acquisition of genetic benefits. Here, I examine the genetic mating system of map turtles, Graptemys geographica in Lake Opinicon. Based on the most conservative estimate, at least 71% of clutches in this population are sired by multiple males. There did not appear to be any relationship between female body size and frequency of multiple paternity. There was a marginally significant effect of multiple paternity on hatching success and survival of clutches, but there was no effect on hatchling morphology or locomotor performance.

This study assessed the principles of ecosystem management and utilized the Northern Map turtle, a species at risk, as a key indicator species to illustrate the importance of preserving riparian habitats and island complexes on an ecosystem scale. Overall, the study explored the population characteristics and use of habitat of the Northern Map turtle (Graptemys geographica) within a small bay within the Gananoque River system in South Eastern Ontario. Results from field observations showed that the bay population of Northern Map turtles appeared to be female biased. Use of habitat features differed by females, males and juveniles at different times throughout the summer (May-August). Females were frequently observed basking within the bay in May and June while males were more frequently observed throughout July and August. Nesting by female Northern Map turtles appeared to be concentrated atop small islands scattered throughout the bay. Nest sites were located within narrow bands of soils. The most prominent difference between site conditions at the monitored nests was soil moisture; this was likely the result of different soil materials at each site. Air and soil temperature did not differ significantly between sites. Additional research could be pursued on the bay population of Northern Map turtles looking at the following: movement patterns by females out of the bay post-nesting, genetic linkages to other satellite populations of Northern Map turtles in the Thousand Islands, hatchling success and sex composition, overall species health due to food availability and lastly the effects of anthropogenic stressors.

This study assessed the principles of ecosystem management and utilized the Northern Map turtle, a species at risk, as a key indicator species to illustrate the importance of preserving riparian habitats and island complexes on an ecosystem scale. Overall, the study explored the population characteristics and use of habitat of the Northern Map turtle (Graptemys geographica) within a small bay within the Gananoque River system in South Eastern Ontario. Results from field observations showed that the bay population of Northern Map turtles appeared to be female biased. Use of habitat features differed by females, males and juveniles at different times throughout the summer (May-August). Females were frequently observed basking within the bay in May and June while males were more frequently observed throughout July and August. Nesting by female Northern Map turtles appeared to be concentrated atop small islands scattered throughout the bay. Nest sites were located within narrow bands of soils. The most prominent difference between site conditions at the monitored nests was soil moisture; this was likely the result of different soil materials at each site. Air and soil temperature did not differ significantly between sites. Additional research could be pursued on the bay population of Northern Map turtles looking at the following: movement patterns by females out of the bay post-nesting, genetic linkages to other satellite populations of Northern Map turtles in the Thousand Islands, hatchling success and sex composition, overall species health due to food availability and lastly the effects of anthropogenic stressors.

Information on the locations for feeding, reproductions, and resting, are essential to effectively protect sea turtle populations and implement conservation efforts. This type of ecological information is critically important for hawksbill turtle conservation in Los Roques Archipelago National Park (LRANP) where turtles have been declining in spite of habitat protection efforts. The goal of this research was to produce a benthic habitat map of LRANP employing in situ visual surveys, remote sensing and geographic information system techniques, and to spatially characterize sea turtle occupancy and patterns of usage by habitat type. Between June and August of 2008, turtle behavior and habitat use were recorded during 159 h of observation, comprising 46 sighting events (n = 20 juveniles, n = 26 female adults). Observed activities were grouped into 4 categories: foraging, resting, swimming, and reproductive behavior. The benthic habitat at each turtle sighting was recorded as one of three categories: coral reef, sand or marine vegetation. Results suggest that the population of turtles within LRANP is comprised primarily of female adults and juvenile individuals and that coral reef is the most important habitat for this species. The most important foraging area in the atoll is a coral patch reef that connects Dos Mosquises Sur and Dos Mosquises Norte. The data in this thesis have been made available in digital and map form to the managers of LRANP for management purposes.