by Roger » Mon Dec 07, 2009 12:00 pm
I am comparing occupancy of certain bird species among study areas. I have 56 areas. Study areas were surveyed 12 times each for 2 years (24 total surveys over the two-year period). I want to compare occupancy among areas based on categorical covariates. However, I am really not interested in estimating colonization rates, extinction rates, or year affects. I just want to determine if occupancy differs among the different categories. Also, I believe that it is appropriate to assume that detectability did not change between the two years. My question: Is it appropriate to run the multi season model, estimating occupancy for each of the two years (without including covariates), then compare the SEs of the psi’s to determine if there was a significant difference among years? And, if no significant difference exists between the two years, combine the two years of data (24 surveys in each area)? Is there a better way to consolidate the two years of data?