Spatial CMR
Using the grid from the Possum example, we can simulate SECR data with a built in function.
With the code provided here, simulate data, then run the null (we wrote this one for you), behavior, and time models; and finally perform model selection and model averaging.
Repeat the same for the different simulated designs (below a-d). Draw your conclusions about the precision of Density estimates based on the different study designs; which of the following is a good study design?:
a- 3 occasions, High movement (sigma=70), low detection (g0=0.2) (simulated in the code above)
b- 3 occasions, Low movement (sigma=20), low detection (g0=0.2)
c- 5 occasions, High movement (sigma=70), high detection (g0=0.6)
d- 10 occasions, High movement (sigma=70), high detection (g0=0.6)
Mark-resight models
As noted in class, an alternative model to the zPNE for mark-resight models is the Immigration-emigration logit-normal estimator (IELNE).
Earlier we ran a model where all the parameters vary in between sessions. Now in addition to this model:
a- Run a null model
b- Run a model where there is variation between sessions, except for the resighting probabilities
c- Compare the three models via AIC