[R-sig-eco] AIC, R-Mark, and nest survival

[Jeff Laake]

This problem piqued my interest, so I read some of the papers.  It is 
fairly easy to use the logistic-exposure approach with glm to analyze 
nest success data. I replicated some simple models with the mallard data 
using logistic-exposure approach.  However, there is one advantage of 
the MARK approach over Shaffer's logistic-exposure approach which he 
discusses in his paper.  In MARK, the survival parameters are daily (or 
whatever time interval) so it is easy to create "continuous" time/age 
covariates whereas with the logistic-exposure model it is necessary to 
split the data into observation intervals and use the average time/age 
for the interval.  It is a minor nuisance to split up the data but using 
average values for observation intervals may not be reasonable if  there 
are long time intervals.

As Shaffer showed they are using the same likelihood and will get the 
same results if they use the same covariates,  Choosing a method will 
depend on the flexibility you want. Ultimately, the most flexible 
approach would be to take the basic likelihood and write your own code 
in R.

--jeff