Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 4 of 4
Full-Text Articles in Animal Sciences
The Ecology Of The Timber Rattlesnake (Crotalus Horridus) In Southeastern Virginia, Scott M. Goetz
The Ecology Of The Timber Rattlesnake (Crotalus Horridus) In Southeastern Virginia, Scott M. Goetz
Biological Sciences Theses & Dissertations
Few studies have examined the relationship between forest canopy structure and the ecology of the timber rattlesnake (Crotalus horridus). I used radiotelemetry to compare the movements, activity range sizes and behaviors of timber rattlesnakes before and after a large-scale natural disturbance that opened a previously closed canopy. The disturbance was Hurricane Isabel which made landfall in northeast North Carolina and southeastern Virginia in 2003. Isabel created gaps in the canopy through tree blowdown, resulting in a 16.6% opening in the forest canopy at my study site, in southeastern Virginia. I compared six years of female tracking data from …
Patterns Of Transience, Sex Bias, And Body Mass In Open-Habitat Rodent Populations, Stephen Edward Rice
Patterns Of Transience, Sex Bias, And Body Mass In Open-Habitat Rodent Populations, Stephen Edward Rice
Biological Sciences Theses & Dissertations
Rodents are assumed to live their lives in circumscribed (natal) areas with males being more prone to disperse than females and juveniles more prone to disperse than adults. To test these assumptions we examined the initial captures of geographic populations of hispid cotton rat, meadow vole, prairie vole, and marsh rice rat obtained through capture-mark-recapture methods. Capture records were obtained from Kansas and Illinois from long-term studies, and through live-trapping in Chesapeake, Virginia. I evaluated proportions of residents and transients, adults and juveniles, and males and females for significant differences among seasons, years, and geographic locations. The overall body masses …
Rats As Forest Pests In Southeastern Virginia: Girdling By The Hispid Cotton Rat Sigmodon Hispidus As A Significant Source Of Mortality Of Loblolly Pines (Pinus Taeda) In A Successional Pine Forest, Robyn M. Nadolny
Biological Sciences Theses & Dissertations
The hispid cotton rat (Sigmodon hispidus) is a common field rodent throughout the southeastern US, where volunteer loblolly pine trees (Pinus taeda) invade open space and begin the process of ecological succession from field to pine forest. Recent analysis of the diet of S. hispidus indicates that loblolly pine bark is stripped and eaten during the winter months. In this study, we explored the extent of rodent girdling on a 1.23 ha grid in a successional pine forest in southeastern Virginia. During the winter of 2005 we observed damage to 65% of trees in our study area, with 98% …
A Comparison Of Adrenal In Toad-Eating And Nontoad-Eating Snakes, Shabnam Mohammadi
A Comparison Of Adrenal In Toad-Eating And Nontoad-Eating Snakes, Shabnam Mohammadi
Biological Sciences Theses & Dissertations
Toads are chemically defended by bufadienolides, a class of cardiotonic steroids lethal to most predators, including many snakes. Bufadienolides bind to Na+K +-ATPase, inhibiting their ability to transport ions. In cardiocytes, this inhibition cause arrhythmia and severely increased contraction strength, which, if prolonged, lead to death. However, several snakes are resistant to bufadienolides and consume toads with no ill effects. Adrenal glands produce hormones that are important for the maintenance of Na+K +ATPase, and may therefore play an important role in countering the negative effects of bufadienolides. Indeed, the toad-eating specialist Heterodon platirhinos has been known to possess enlarged, and …