BIOE 370 1st Edition Lecture 14 Outline of Last Lecture II. Ecological Responses to Climate ChangeOutline of Current Lecture III. Demographya. Life HistoryIV. Survivorship CurvesCurrent Lecture* No class FridayDemography- Study of processes controlling birth and death rates in populationso Population growth/ dynamicso Life history (describes demography) trade-offs Ex: Hyena – repeated reproduction, but only producing small amount of offspring. Few offspring and a lot invested in those offspring  Ex: Armadillo – Always produce 4 offspring, quadruplets.  Ex: Wild Dogs – High annual survival rates, each individual has about 10 offspring. Investing in large litter. Heaviest litter mass relative to body mass. Trade-off: survival rate for offspring is not as high Ex: May fly – fast life history, time scale of days. Large number of offspring and then dies. Each offspring has tiny probability of survivingSurvival – Survivorship Curves: - 1st: Sky in demographic analysis: identify appropriate time scale for age classeso Life-stage classesThe survivorship Curves:- Type I  large, long lived, low population  k-selected- Type II  Intermediate mammals, birds- Type III  Invertebrates, plants  R-selected(look at log-scale plotted in graph and relationship)In general:Log-scale –- Allows comparison of mortality rate across ages of populationsLinear-scale - - Allows comparison of proportion alive (or dead) across ages of populationsA straight line represents a constant survival rateSurvivorship Curves for Fish:- Obviously wrong – increasing and then decreasing. Why?o Data obtained by shocking fish or netting fish If collect net data, the ones that are smaller than the net size get missed so wrong