Download or read book The Distribution and Abundance of Alligator Snapping Turtles Macrochelys Temminckii in Southwestern Louisiana written by Cybil White Covic and published by . This book was released on 2014 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Relative Abundance Population Structure and Habitat Utilization of the Alligator Snapping Turtle Macrochelys Temminckii and Eastern Snapping Turtle Chelydra Serpentina in Southeastern Missouri written by Timothy Charles Lescher and published by . This book was released on 2010 with total page 75 pages. Available in PDF, EPUB and Kindle. Book excerpt: Alligator Snapping Turtles have not been surveyed extensively in Missouri since 1993-94. Six sites that were sampled in the early nineties were re-sampled in 2009 at the same locations where previous researchers trapped. Significantly fewer significantly fewer Alligator Snapping Turtles were captured per trapnight at all six sites. The population structure of the Alligator Snapping Turtles had a significantly different distribution in 2009 compared to 1993-94. The population structure had shifted toward smaller individuals, and fewer adult males and adult females were captured in 2009 compared to 1993-94. The 1993-94 structure was normally distributed while the 2009 structure exhibited a negative skew. Populations sampled in 2009 have an extremely female-biased sex ratio and fewer large adults, which may impact the population negatively in the future. Future sampling of Alligator Snapping Turtles at these six sites is recommended to continue monitoring their long-term trends in relative abundance and population structure. Alligator Snapping Turtles (Macrochelys temminckii) and Eastern Snapping Turtles (Chelydra serpentina) were captured during the summers of 2009 and 2010. Habitat characteristics were collected at each trap that captured these species. Subsequent analysis of data revealed that Alligator Snapping Turtle presence at trap sites was characterized by increased physical structure in the stream, water depth, relatively high levels of detritus, and warmer temperatures when compared to Eastern Snapping Turtles; the amount of aquatic vegetation and bottom surface (i.e., mud or non-mud substrate) were important in characterizing Eastern Snapping Turtle presence in traps. Eastern Snapping Turtles and Alligator Snapping Turtles did not use the same areas spatially, and were only trapped at the same location once in 557 trapnights. Future conservation plans for the Alligator Snapping Turtle and Eastern Snapping Turtle should consider the microhabitat characteristics of sites utilized by these turtles, along with the possibility of interspecific interactions within Chelydridae.
Download or read book Habitat Use and Movements of Alligator Snapping Turtle Macrochelys Temminckii Hatchlings written by Amity Ann Bass and published by . This book was released on 2007 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this study was to gather data concerning home range, movements, and habitat use of hatchling Alligator Snapping Turtles ... in order to better manage for this species. Nineteen hatchlings were tracked at Black Bayou Lake National Wildlife Refuge during 2006. Ten animals were successfully tracked during the spring and nine during the fall. Hatchlings that were incubated in the laboratory or naturally on the railroad causeway were heavier and had longer carapace lengths than those naturally incubated along the forest-old field edge of the peninsula (p
Download or read book Population Status Distribution and Home Range of the Alligator Snapping Turtle Macrochelys Temminckii in the Suwannee River Florida written by Travis M. Thomas and published by . This book was released on 2013 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: The alligator snapping turtle (Macrochelys temminckii) has experienced population declines throughout much of its range because of extensive harvest. Little is known about the genetically and morphologically distinct population of Macrochelys in the Suwannee River. In Georgia, efforts failed to capture Macrochelys in the Suwannee River, creating concern about this species status. To determine the status of Macrochelys in the Suwannee River, a mark-recapture and telemetry study was conducted between 2011 and 2013. In total, 132 individual Macrochelys were captured (21.2% juveniles, 17.4% females, and 61.4% males). Sex ratio was male-skewed (3.5:1) and 41% of males weighed \U+2265\45kg. Relative abundance and density estimates revealed an uneven distribution of turtles throughout the river, with more productive river sections maintaining higher population densities and larger turtles. Mean linear home ranges were 1,896 m ± 252 m for males and 1,615 m ± 301 m for females. Telemetry data revealed habitat use patterns not previously reported for Macrochelys, with individuals making overland movements between the floodplain and river channel. Side-scan sonar maps paired with turtle locations indicated coarse woody debris, undercut banks and large rocks are important habitat during low water levels. Bush hook surveys and radiographs revealed a positive correlation between bush hook abundance and number of ingested hooks. Macrochelys in the Suwannee are more numerous than previously thought; however, several threats exist including fish hook ingestion, boat propeller damage, and the removal of woody debris.
Download or read book Spatial Ecology of Adult Alligator Snapping Turtles Macrochelys Temminckii written by Mitchell James Ray and published by . This book was released on 2010 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Population Structure and Reproduction of Alligator Snapping Turtles Macrochelys i e Macroclemys Temminckii at Black Bayou Lake National Wildlife Refuge written by Lori Brianne Woosley and published by . This book was released on 2005 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Spatial Ecology of Juvenile Captive reared Alligator Snapping Turtles Macrochelys Temminckii in Northeastern Louisiana written by Cody Lee Townsend and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Alligator Snapping Turtle written by Peter Charles Howard Pritchard and published by . This book was released on 1989 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Map Turtle and Sawback Atlas written by Peter V. Lindeman and published by University of Oklahoma Press. This book was released on 2013-12-02 with total page 489 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covering all facets of the biology of a little-known genus, Peter V. Lindeman’s lavishly illustrated Map Turtle and Sawback Atlas is both a scientific treatise and an engaging introduction to a striking group of turtles. Map turtles and sawbacks, found in and along rivers from Texas to Florida and north to the Great Lakes, fascinate ecologists and evolutionary biologists. Over a short geologic time span, these turtles achieved exceptional biological diversification. Their diets are also exceptionally diverse, and a significant difference in size distinguishes males from females. Adult males are typically half or less the shell length of adult females, making map turtles and sawbacks the champions of sexual dimorphism among not only turtles but all four-legged vertebrates. Aesthetics also draw biologists and hobbyists to map turtles and sawbacks. While the male Sabine map turtle may look to some like a “pencil-necked geek,” as the author puts it, markings on the shell, limbs, head, and neck make map turtles among the most attractive turtles on earth. Sawbacks feature a striking ridge down their shell. Few turtles show themselves off to such advantage. Photographs included here of Graptemys basking poses reveal to what improbable heights these turtles can scale, the spread-eagle sunning stances they adopt, the stacking of individuals on a crowded site, and the heads that warily watch the world above the waterline. In lively prose, Lindeman details the habitat, diet, reproduction and life history, natural history, and population abundance of each species. A section on conservation status summarizes official state, federal, and international designations for each species, along with efforts toward population management and recovery as well as habitat preservation. The author also outlines promising avenues for future research, ranging from the effects of global climate change on populations to strategies for combating expansion of the pet trade.
Download or read book Nesting Ecology in Reintroduced Alligator Snapping Turtles Macrochelys Temminckii written by Jessica Leigh Miller and published by . This book was released on 2012 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Ecology of Hatchling Alligator Snapping Turtles Macrochelys Temminckii written by Sarah Spangler and published by . This book was released on 2017 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: Little is known about the first year of life for many of the world’s freshwater turtles. This is due in part to their cryptic nature and the difficulty of locating hatchlings in the wild. The lack of information about this demographically important age group has led researchers to draw conclusions from indirect inferences about survival rates and ecological roles of hatchlings that may or may not be accurate. To begin filling in some of these gaps, I focused on the first year in an alligator snapping turtle’s life. I studied: (1) circadian and circannual patterns of activity, (2) growth rates and how they are related to activity rates, (3) habitat preferences, (4) fall movement patterns, and (5) predation patterns. My study site was within the species’ natural range in southeastern Oklahoma. Unlike adults, hatchlings followed a predominantly diurnal activity pattern for much of the year, with peak activity occurring during the mid-hours of the day. The diurnal habit of hatchlings may be a strategy to temporally partition themselves from nocturnal predators. There were no significant relationships between growth rates and activity rates during any period, potentially due to small sample size. Hatchlings were located in areas of increased cover and shallower water depths, when compared to random locations. Their movement patterns were characterized by an initial movement away from the site of release to a location with suitable habitat characteristics, and they tended to stay at these locations for extended periods. I documented depredation by fish, but not by terrestrial predators such as raccoons.
Download or read book Survivorship and Sources of Mortality in Nests of the Alligator Snapping Turtle Macrochelys Temminckii at Black Bayou Lake National Wildlife Refuge written by Samuel Robert Holcomb and published by . This book was released on 2010 with total page 192 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Ecology of the Alligator Snapping Turtle Macrochelys Temminckii in Oklahoma written by J. Daren Riedle and published by . This book was released on 2001 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reproductive Biology and Conservation Genetics of the Alligator Snapping Turtle macrochelys Temminckii written by Amber R. Teare and published by . This book was released on 2010 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: Author's abstract: The alligator snapping turtle (Macrochelys temminckii) is a highly aquatic turtle only found in Gulf of Mexico drainages. The biology of this species remains relatively unknown, despite years of harvest and use as a zoological attraction. The purposes of this study were to (1) determine gender size classes and assess sexual size dimorphism, (2) delineate the reproductive cycle of M. temminckii, particularly their sex steroid seasonality, and (3) evaluate possible genetic divergence between M. temminckii found in southwest Georgia and northern Florida. Alligator snapping turtles exhibit pronounced sexual size dimorphism as adults. However, determining sex in smaller individuals is difficult. The purpose of this study was to assess gender size classes and sexual dimorphism in Macrochelys temminckii. Alligator snapping turtles in southwest Georgia were trapped from March 2008 to April 2010. Captured turtles were bled, sexed based on size and ultrasound, and measured for multiple characteristics. For all measurements, adult males were larger than females. The relationships between carapace length, plastron-to-vent length, and testosterone levels were used to determine gender of smaller individuals. To ensure accurate sexual assignment when studying M. temminckii, data from multiple methods (morphological measurements, ultrasonography, testosterone levels, and, laparoscopy) should be used. To delineate the reproductive cycle of M. temminckii, blood samples were taken from captured individuals, and plasma testosterone and estradiol were measured using enzyme immunoassay. Males exhibited seasonal changes in testosterone levels, with maximum levels occurring in October. Mating behavior was elucidated from the appearance of wounds on males that only occurred in April. Females displayed seasonality in testosterone and estradiol levels, with relative peaks occurring in March and April (mating and ovulation) and September and October (follicular development). Genetic structure between M. temminckii populations separated by a dam and under different hunting pressures was assessed using microsatellite loci. Average number of alleles per locus and number of unique alleles was higher for the Florida population. Genetic structure was detected between the populations (FST = 0.043, p = 0.001). The rapid development of structuring between Florida and Georgia M. temminckii warrants further investigation into the effects of fragmentation and overexploitation on this species.
Download or read book Sabine Neches Waterway Channel Improvement Project Southeast Texas and Southwest Louisiana written by and published by . This book was released on 2011 with total page 778 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Demographics and Habitat Selection of the Alligator Snapping Turtle Macrochelys Temminckii written by Christopher A. F. Howey and published by . This book was released on 2007 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Assessment of Paternity in Alligator Snapping Turtle Macrochelys Temminckii Clutches written by Lauren Besenhofer and published by . This book was released on 2006 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three of seven microsatellite loci tested on Machrochelys were variable (from three to five alleles per locus) and provided evidence of multiple paternity in 13 out of 14 clutches from Black Bayou Lake National Wildlife Refuge. These findings have implications for the mating strategy of Macrochelys, including the prevalence of sperm storage and multiple matings. Multiple paternity is an important strategy in threatened or endangered species because it may help increase effective population size and genetic variability.
