University of Missouri - Saint Louis

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An oral examination in defense of the dissertation for the degree

Doctor of Philosophy in Biology

Jeffery A. Ettling
M.S. in Biology, May, 1994, Southern Illinois University at Edwardsville
B. S. in Biology, May, 1986, Southern Illinois University at Edwardsville


Spatial Ecology, Genetic Diversity and Population Structure of Armenian Vipers, Montivipera raddei, in Two Different Landscapes

 

Abstract

In an effort to gain a better understanding of the impact that human-modified landscapes are having on snake populations, I studied the spatial ecology, gene diversity and population structure of the Armenian Viper, Montivipera raddei in two different landscapes in Armenia. We first examined the spatial ecology and habitat use of Armenian Vipers in a human-modified landscape with a combination of agricultural fields and overgrazed native steppe habitat. While there were no differences in movement rates for either sex through croplands compared to steppe, we did find that males had larger home ranges during the spring if it included cropland. While the mosaic of steppe and croplands does not appear to impede seasonal movements in this human-modified landscape, vipers overwhelmingly prefer steppe to cropland. We were then interested in how the spatial use of vipers in this heavily altered habitat compared to a population inhabiting a recovered-natural habitat. The home range size and mean movements were significantly smaller and the abundance of small mammals was significantly higher in the recovered-natural landscape. However, we found no correlation between body condition and home range size. In fact, snakes inhabiting the two landscapes had equivalent body condition. These data suggest that snakes in the human-modified landscape have larger home ranges in order to find enough prey over the course of an active season. While the radiotelemetry data provided insight into the spatial ecology of Armenian Vipers in these two landscapes, we were also interested in examining their genetic diversity and population structure. We collected genetic samples from two locations within each of the two landscapes. At the local scale there was no significant differentiation between sampling locations, but on the regional scale we found the two geographically separated populations to be significantly differentiated from one another. The focus of conservation efforts for the Armenian Viper in altered habitat should be on maintaining corridors with high quality habitat that allow for seasonal movements, shelter, foraging and gene flow. Due to the strong genetic differentiation between the two populations, we also recommend that regional populations be managed as independent conservation units.


 

Date: April 26, 2013

Time: 9:30 – 10:30 a.m.

Place: Research 121

 

Defense of Dissertation Committee

 

Patricia Parker, Ph.D. (Advisor)

Robert Marquis, Ph.D.

 

Patrick Osborne, Ph.D.

Harry Greene, Ph.D.