Date of Award

2007

Degree Name

Biological Sciences

College

College of Science

Type of Degree

M.S.

Document Type

Thesis

First Advisor

Thomas K. Pauley

Second Advisor

Dan K. Evans

Third Advisor

Jayme L. Waldron

Abstract

Since 1971, documented Rough Greensnake (Opheodrys aestivus) occurrences in West Virginia have declined from approximately 100 to less than 20 occurrences in the last 10 years. In contrast to the decline of Rough Greensnakes in WV, Smooth Greensnake (O. vernalis) populations appear to be stable over the same period of time. Historic sites from the West Virginia Biological Survey were cross referenced with habitat descriptions in published literature to establish research locations. One hundred nineteen Rough and Smooth Greensnakes were measured for snout-vent length and total body length, and of these, 78 were measured in detail for external head morphology characteristics. Stomachs of field-captured specimens were flushed to identify prey, and in preserved specimens the gastro-intestinal tracts were dissected and examined for prey items. Plant community data were collected at each research site (N=51) along 150m transects to define their habitat characteristics. Of the 6 month active period, Rough Greensnakes had the most captures in September, accounting for 30%. In comparison, Smooth Greensnakes had the most captures in June, accounting for 33%. Exponential regression showed a positive correlation between total length and weight for Smooth Greensnakes (R2 = 0.9136) and Rough Greensnakes (R2 =0.7124). Species occupied different habitats, with Rough Greensnakes found along forest edges near roadsides and Smooth Greensnakes in open fields with sparse vegetation. There was a statistically significant difference between the habitat types that were occupied by Rough and Smooth Greensnakes (p< 0.001). Only Opheodrys aestivus adults were found, while Opheodrys vernalis was represented by age groups from hatchlings to older adults. The data suggest that differences in both activity period and habitat preference may explain differences in population structure.

Subject(s)

Rough green snake - Habitat - West Virginia.

Smooth green snake - Habitat - West Virginia.

Rough green snake - Ecology.

Smooth green snake - Ecology.

Rough green snake - Morphology.

Smooth green snake - Morphology.

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