Homing Behavior And Orientation In The Gopher Tortoise Gopherus Polyphemus

Author : Jennifer N. DeSha
Publisher :
ISBN 13 :
Total Pages : 65 pages
Book Rating : 4.:/5 (129 download)

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Download or read book Lack of Plasticity in Gopher Tortoise (Gopherus Polyphemus) Nesting Behavior and Fecundity in a Translocated Population written by Jennifer N. DeSha and published by . This book was released on 2021 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: Author's abstract: Gopher tortoises (Gopherus polyphemus) are a threatened, keystone species that play important roles in upland habitats throughout the southeastern United States. Climate change could have diverse and strong effects on the fecundity and population demographics of gopher tortoises, as they are long-lived reptiles that rely on environmental temperatures for thermoregulation and sex determination. I used a population of translocated gopher tortoises at Nokuse Plantation, located in the panhandle of Florida, as a common garden experiment to assess whether plasticity of several nesting behaviors (i.e., nest temperature, depth, and orientation) and components of fecundity (i.e., clutch size, egg size, hatching success) might compensate for changes in environmental conditions. I compared nest characteristics among translocated females (from across the state of Florida) and examined how multiple measures of environmental distance, such as difference in warm season temperature between the translocation and origin sites, impacted aspects of fecundity. I found that tortoises did not exhibit plasticity and did not adjust their nesting behaviors in response to novel conditions. Tortoises that originated from climates that were more dissimilar from that of the translocation site placed their nests at different locations within the burrow apron, under differing amounts of canopy cover, and at different depths. Environmental distance of translocation also impacted hatching success, although there was no direct impact of nest site selection on hatching success, suggesting that differences in hatching success due to female origin are more a consequence of physiology (e.g., developmental processes) than female behavior. Although there was a high degree of variability in the direction of the effect of environmental distance – i.e., whether tortoises from more or less similar climates had greater hatching success – these results may indicate a strong degree of local adaptation that is still apparent even several years after translocation. These findings suggest that gopher tortoises may not be resilient to impending environmental changes, and behavior plasticity should not be expected. Effects on nest site selection, incubation temperatures, and hatching success suggest that translocation guidelines should consider climate differences when selecting relocation sites.