Hi,
I am hoping to get some clarity on how to incorporate covariates into 2-species (single season) occupancy models (psiBA conditional parameterization) in RPresence, specifically covariates on occupancy that have a by-species interaction.
If I want to include land cover covariates on occupancy (called NativeForest and Crops here) as well as an interaction by species, plus an occurrence-level interaction (psiBA not equal to psibA), would this be correct (for psi):
OccMod(model=list(psi~SP+INT+NativeForest+Crops+NativeForest*SP+Crops*SP,
p~SP)......
Or should the covariate interaction be between both SP and the occurrence-level interaction (INT)? would this just mean that in addition to an interaction by species, the covariate will interact with psiBA and psiBa differently? I imagine that would look something like this but I'm not sure...
OccMod(model=list(psi~SP+INT+NativeForest+Crops+NativeForest*SP*INT+Crops*SP*INT,
p~SP)......
Thanks for any/all help provided. Hopefully this question makes sense... In general I am just seeking clarification on the difference between covariate interactions with SP and INT, and whether/why it makes sense to include both in the same model or not.
-Vanessa