A Provisional Model of Demography in Desmognathus ocoee (Amphibia, Plethodontidae)

A provisional model of survival and demography in two populations of the salamander Desmognathus ocoee in the Cowee and Nantahala mountains of North Carolina was derived from existing data on growth, metamorphic timing, age at first reproduction, and fecundity. The model assumed stationary populations with stable age distributions ( R0 = 1.0, r = 0), wherein observed ages at first reproduction in females were equal to optimal ages. Survivorship was partitioned into pre- and post-metamorphic phases, i.e., egg/larval survival and juvenile/adult survival. Premetamorphic survival estimates were fitted to the model to meet the requirement that R0 = 1.0. Equivalence of optimal and observed age at first reproduction in females, as proposed, could reflect synergistic tradeoffs between (1) growth and reproduction, and (2) mortality and reproduction. The two populations show extreme similarity in life history and demography, in contrast to differences between the Cowee and Nantahala desmognathine assemblages.