NERS 488/688 Homework 4

 

Date set 1.

  1. Use the input file ners488hw3set1.inp in the Public folder, which contains capture histories for a sample of animals.  The study was done over     a     period of years when hunting regulations were made progressively more liberal (longer seasons etc.).  Managers are specifically interested in        whether changes in hunting regulations have affected adult survival.  There are four groups adult males and females and juvenile males and females.
  2. Use Program Mark to find the best (lowest AIC) model for these data.  Is there support for an effect of hunting regulations?  Hint: You can        build a model with a trend in survival by coding a sequence of numbers in the column identifying a group.  See Mark manual.
  3. Use Program Release to test the hypotheses of equal catchability and equal survival probabilities for individuals in the sample.
  4. Use the chi-square statistic/df from the total chi-square from Tests 2 and 3 in Release to calculate c-hat.  Use c-hat to adjust AIC, producing QAIC scores.
  5. Produce parameter estimates for the best model.
  6. Produce model averaged estimates of parameters.

Data set 2.

  1. Use data set nres488tdhw3.inp from the Public folder.  This data set contains capture histories from about 100 individuals fro whom mass was measured at the start of the study.  Mass has been standardized to a normal distribution with mean = 0 and SD = 1.
  2. Assess the role of mass in survival relative to other models for survival.  You may want to simplify models for capture probability before considering models of survival.  Hint:  You will need to incorporate mass as a covariate in the Design matrix to test effects of mass on survival.
  3. Prepare a graph of the relationship between condition index and survival.  Hint: You will need to use the back-transformed logit and the betas for the intercept and the covariate.  Using the logit and the range covariate calculate expected survival for a sample of covariate values.