I am currently carrying out research on an invasive mammalian predator and whether there is any influence of a native predator on its occurrence and detectability. As part of this, I have developed single-season occupancy models for the individual species and am now carrying the findings from that model forward into two species single season models using RPresence. I wanted to double-check that my formulae and interpretations of them were correct before I went too far into it.
I plan to analyse wether there is an effect of habitat type (occupancy and detection), topography (occupancy and detection), and whether cameras pointing into the road were active (detection component only).
For my current example, I have just included habitat type to keep it simple.
- Code: Select all
Mod_1<-occMod(model=list(psi~1,p~1),data=data,type="so.2sp.1",param="PsiBA")
Mod_2<-occMod(model=list(psi~SP,p~SP),data=data,type="so.2sp.1",param="PsiBA")
Mod_3<-occMod(model=list(psi~SP,p~SP+INT_o),data=data,type="so.2sp.1",param="PsiBA")
Mod_4<-occMod(model=list(psi~SP+INT,p~SP),data=data,type="so.2sp.1",param="PsiBA")
Mod_5<-occMod(model=list(psi~SP+INT,p~SP+INT_o),data=data,type="so.2sp.1",param="PsiBA")
Mod_6<-occMod(model=list(psi~SP+Hab_RF,p~SP+Hab_RF),data=data,type="so.2sp.1",param="PsiBA")
Mod_7<-occMod(model=list(psi~SP+Hab_RF,p~SP+INT_o+Hab_RF),data=data,type="so.2sp.1",param="PsiBA")
Mod_8<-occMod(model=list(psi~SP+INT+Hab_RF,p~SP+Hab_RF),data=data,type="so.2sp.1",param="PsiBA")
Mod_9<-occMod(model=list(psi~SP+INT+Hab_RF,p~SP+INT_o+Hab_RF),data=data,type="so.2sp.1",param="PsiBA")
Mod_1 Null model
Everything held at constant 1
Mod_2 ΨA, ΨBA = ΨBa, pN = rN
Neither habitat nor Species A presence influences Species B occupancy/detection
Mod_3 ΨA, ΨBA = ΨBa, pN, rN
Only Species A presence influences Species B detection
Mod_4 ΨA, ΨBA, ΨBa, pN = rN
Only Species A presence influences Species B occupancy
Mod_5 ΨA, ΨBA, ΨBa, pN, rN
Only Species A presence influences Species B occupancy/detection
Mod_6 ΨA(Hab), ΨBA(Hab) = ΨBa(Hab), pN (Hab) = rN (Hab)
Only habitat influences Species B occupancy/detection
Mod_7 ΨA(Hab), ΨBA(Hab) = ΨBa(Hab), pN (Hab), rN (Hab)
Habitat-mediated influence of Species A presence on Species B detection
Mod_8 ΨA(Hab), ΨBA(Hab), ΨBa(Hab), pN (Hab) = rN (Hab)
Habitat-mediated influence of Species A presence on Species B occupancy
Mod_9 ΨA(Hab), ΨBA(Hab), ΨBa(Hab), pN (Hab), rN (Hab)
Habitat-mediated Species A presence influence on Species B occupancy/detection
If anyone could have a quick look at the above and confirm whether I'm heading in the right direction with regards to my code and the questions they are asking, it would be greatly appreciated.
Thanks for your time.
Tom Bruce