1. When model averaging rB across models where rBA ≠ rBa, Richmond et al. (2010), last paragraph pg. 2041

Does rB = rBA + rBa as seems likely from MacKenzie (2006) p. 237 or is there a more complicated extrapolation process?

2. If so, does it seem plausible that rB calculated as rBA+rBa would become much higher in models where rBA and rBa are freed up to be estimated conditionally than in models where they are forced to be estimated unconditionally?

3. Finally, when calculating standard error for an estimate of rB calculated from rBA + rBa, is the approach recommended elsewhere for combing standard errors of within model averages (SE = sqrt(sum(VAR[i]))/N, where VAR[i] is the variance for each site-specific estimate of psi (ie SE^2) suitable or should some alternative approach be considered?

Any help with some or all of the questions are kindly appreciated. Self-taught beginner without access to expert advice or training, so please keep answer simple and provide textual explanations for equation shorthand if possible.

References:

• MacKenzie, D.I., 2006. Occupancy estimation and modeling: inferring patterns and dynamics of species occurrence. Academic Press, London UK.

• Richmond, O.M.W., Hines, J.E., Beissinger, S.R., 2010. Two-species occupancy models: a new parameterization applied to co-occurrence of secretive rails. Ecol Appl 20, 2036-2046.