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Detection, Occupancy, Abundance, And Mercury Accumulation Of The Alligator Snapping Turtle (Macrochelys Temminckii) In Texas, David Rosenbaum
Detection, Occupancy, Abundance, And Mercury Accumulation Of The Alligator Snapping Turtle (Macrochelys Temminckii) In Texas, David Rosenbaum
Electronic Theses and Dissertations
Land use practices and physical alterations of ecosystems result in habitat loss and fragmentation, while chemical alterations, such as pollutant input, reduce habitat quality and health of exposed organisms. Here, I investigated the effects of watershed- and local-scale environmental variables on the occupancy, abundance, and mercury accumulation of a threatened aquatic species (Macrochelys temminckii, i.e., alligator snapping turtle) within the southwestern periphery of its distribution. Hierarchical modeling suggested the distribution of the species is more affected by watershed-scale land-cover than local habitat, and provided a baseline estimate of average species abundance across its range in eastern Texas. Abundance …
Detection And Occurrence Of Nerodia Harteri (Serpentes: Colubridae) In An Upper Portion Of The Brazos River Watershed, Jessica Yates
Detection And Occurrence Of Nerodia Harteri (Serpentes: Colubridae) In An Upper Portion Of The Brazos River Watershed, Jessica Yates
Electronic Theses and Dissertations
Semiaquatic snakes are disproportionately impacted by habitat alteration adjacent to wetlands because of their reliance on both terrestrial and aquatic habitats. Brazos River Watersnakes, Nerodia harteri, are endemic natricines with one of the most restricted geographic ranges in North America. I quantified detection and site occupancy probabilities of N. harteri and its sympatric congeners (N. erythrogaster and N. rhombifer), as well as microhabitat selection within the Nerodia community. Within occupied transects, search effort was positively correlated with detecting N. harteri, whereas environmental and/or habitat variables were better predictors for detecting the sympatric congeners. Microhabitat selection between …
Bryophyte Assemblages On American Hornbeam (Carpinus Caroliniana) And The Surrounding Arboreal Communities Within The Forest Of East Texas, Cassey Edwards
Bryophyte Assemblages On American Hornbeam (Carpinus Caroliniana) And The Surrounding Arboreal Communities Within The Forest Of East Texas, Cassey Edwards
Electronic Theses and Dissertations
The bryophytes, the non-vascular plants, include the mosses (Bryophyta with approximately 13,000 species), the liverworts (Marchantiophyta with approximately 5,000 species), and the hornworts (Anthocerotophyta with approximately 150 species). Initial observations indicated that the midstory tree Carpinus caroliniana Walter (American hornbeam) has a bryophyte composition with an unusually high diversity of leafy liverworts. Voucher samples were taken from the four intercardinal directions (Northeast, Northwest, Southwest, and Southeast) from six Carpinus trees and their nearest neighbor that was neither Pinus nor another Carpinus at each of six sites across East Texas. Percent coverage, species richness, Shannon’s diversity and Pielou’s evenness were computed. …
Food Habits Of Snakes In An East Texas State Fish Hatchery, John L. Malloy
Food Habits Of Snakes In An East Texas State Fish Hatchery, John L. Malloy
Electronic Theses and Dissertations
A study was conducted from 1 August 1969 to 1 August 1970 in the Jasper State Fish Hatchery near Jasper, Texas to determine the amount of predation by snakes on fish being propagated. The hatchery consisted of 63 earthen ponds. A total of 373 snakes were captured. Results of stomach contents analyses of the 206 snakes containing food were calculated in per cent frequency of occurrence and per cent volume. Frogs, primarily Ranidae, were found to be the major food item. Fish were taken far less frequently, representing only 13.3 % (by volume) and 15.5 % frequency of occurrence. The …