Doctoral Dissertations

Date of Award

8-1986

Degree Type

Dissertation

Degree Name

Doctor of Philosophy

Major Professor

Thomas G. Hallam

Committee Members

Arthur C. Echternacht, Stephen Ellner, Susan E. Riechert

Abstract

Fecundity in Desmognathus fuscus is positively correlated with body size and reproduction is annual. Females in a Southern Appalachian population oviposited beneath moss during mid summer; hatching occurred 40 to 60 days thereafter. Based on laboratory studies, females probably defended their eggs against other salamanders but not against snakes. Reproductive success over the entire population was low in all three years of the study and varied between years. Successful nests usually hatched over 70 percent of the original clutch. The major source of egg mortality probably was predation.

Females in the natural population usually did not increase body length from year to year. Females given high levels of food in the laboratory grew, accumulated visible fat deposits, and contained what seemed to be fully developed ova earlier in the spring than females in the natural population. Carcass lipids probably were mobilized for energy during summer brooding and overwintering.

Analysis of a control theory model of Desmognathus reproductive allocation predicted that female salamanders should grow if enough food is available and always should provide maternal care during egg brooding. Numerical analyses suggest that quantitative results are sensitive to conversion rate and parameters that affect clutch mortality. Large model salamanders had high fecundity and reproductive success; small females had low reproductive success and limited growth because of the energetic demands of reproduction.

Download
Files over 3MB may be slow to open. For best results, right-click and select "save as..."

Share

COinS