Project E2: Growth, Vital Statistics and Energy Budget
|Title||Modeling growth, vital statistics, and energy budget of sauropods: key features contributing to gigantism|
|Principal Investigators||PD Dr. Eva Maria Griebeler, Dr. Martin Sander|
|Researchers||Katja Waskow, MSc, Dr. Jan Werner|
Age- and size specific mortality rates and fecundities show considerable variation among species. They reflect characteristics of life-cycles (e.g. age at sexual maturity, longevity), determine the demography (e.g. intrinsic rate of increase, generation time), and vital statistics of populations. Fecundity and growth in body size are linked because the energy uptake of an organism is limited. Body size is also linked to mortality and to the proportion of energy uptake required for the maintenance of the organism. Here, we will establish age- and size specific mortality rates and fecundities for sauropods by applying different modelling methods. These include an approach that is based on the hotly debated metabolic theory of ecology (MTE). We will also elaborate a simple model for age- and size specific allocation of energy to maintenance, growth and reproduction. These models will allow us to test a number of current hypotheses on life-cycles of sauropods with respect to their reproductive biology, mortality schedule and growth in body mass. Mortality and fecundity rates of extant taxa (birds, crocodiles, turtles and mammals) will be used to validate our models and to base our extrapolation of results for sauropods. Empirical data on extant taxa will compiled from the literature, but growth curves for sauropod will be generated by original research on bone histology. Our project provides a further test of MTE because mortalities and fecundity will be estimated for a larger group of extant taxa than those analyzed for MTE.