I'm running the two-species model using the phi parameterization. My data set consists of 168 sites surveyed up to three times each for two secretive marsh birds. I set up the detection history data with 168 rows for the first species and 168 rows for the second (336 total rows). My first run estimated all 8 parameters (psiA,psiB,phi,pA,pB,pA',pB',pAB) and went smoothly. The model with the assumption that detection probability is independent (psiA,psiB,phi,pA,pB,pA',pB') also went fine. However, when I ran the model which assumes equal detection probabilities (psiA,psiB,phi,pA,pB,pAB) it should have 6 parameters, but in the results browser and in the model output it only shows 5; the pAB parameter was not computed, even though it appeared correctly in the design matrix. Also, when I tried to run the model which assumes that occupancy is independent (psiA,psiB,pA',pB',pA,pB,pAB), Presence crashed several times and the results file was incomplete. Any help much appreciated!
Cheers,
Orien