[PDF] Observations On The Population Ecology Of The Spotted Turtle Clemmys Guttata Near The Northern Limit Of Distribution eBook

Author : Wayne G. Landis
Publisher :
Page : 18 pages
File Size : 25,94 MB
Release : 1983
Category :
ISBN :

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The population dynamics and structure of the spotted turtle, Clemmys guttata, were studies from 1970 until 1982. Carroll Island was the site of chemical testing from post WW II until 1971. Special consideration was given to the impact upon the populations of turtles by the chemicals released on Carroll Island. Several findings are noteworthy. The number of juveniles on the island has steadily declined over the 12 years of sampling. The current (1982) population is half of that estimated for 1972-73. The proportion of females dropped as low as 0.25 of the population. Four possible hypotheses are delivered to explain the observations. The most likely explanations are that a temperature anomaly or natural catastrophe dramatically reduced the proportion of females present. At the same time the population of turtles overshot the carrying capacity of the environment after cessation of an artificial or natural constraint.

Author : Amanda M. Rocker
Publisher :
Page : 88 pages
File Size : 29,9 MB
Release : 2022
Category : Clemmys guttata
ISBN :

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Reptiles are experiencing decreased population sizes and declines in number of populations. Despite this overall pattern, for many species, there remains insufficient data to understand population trends, let alone the specific causes of these declines. One species experiencing severe declines, but sparse assessment is the spotted turtle (Clemmys guttata), a freshwater species found in wetlands in Eastern North America and classified as endangered under the IUCN Red List. This decline likely has occurred because of potential threats such as predation, collection for the pet trade, and habitat loss. I studied the size class distributions of turtles in Maryland and Delaware populations based on frequency of juvenile and adult turtles. I found that C. guttata populations had a negatively skewed size distributions at all study sites. However, they were primarily individuals in the 90-100 mm plastron length size range, while larger, older, individuals were not typically present. Additionally, I analyzed the potential predation of C. guttata based on predator-caused injuries and assessing predator abundance via camera traps. Clemmys guttata had a greater rate of predator-caused injuries compared to other common turtle species; however, there was no correlation between injury rate and predator activity, specifically regarding raccoons (Procyon lotor). My results suggest while there was a large proportion of adults in populations of C. guttata at my sites, very old adults were absent. This was potentially caused, in part, due to predation, but the explanation for high injury rates of C. guttata is complicated and likely involves other factors such as human removal for the pet trade.

Author : Kate Cassim
Publisher :
Page : 90 pages
File Size : 21,56 MB
Release : 2006
Category : Clemmys guttata
ISBN :

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"The spotted turtle (Clemmys guttata) is categorized as protected and a species of special concern in New York State. Understanding the habitat use, movement patterns, and life history characteristics of this species will be essential for any future efforts to provide the necessary habitat requirements for their successful recovery and management. Rochester Institute of Technology partnered with the Seneca Park Zoo and the New York Department of Environmental Conservation to investigate the release of captive-bred spotted turtles. The goal of this study was to determine the movements, habitat use, survivorship, and growth of the captive-bred spotted turtles in a natural environment. The release of suitable numbers of captive-bred spotted turtles into a proper environment where their habitat and resource needs are met should lead to individual survival and the establishment of a sustainable population. During this study, the majority of turtles were lost due to three major causes, premature battery failure, death due to predation, and death due to starvation. The results showed that the longer an individual was part of the study the more weight they lost (p=