Close x Open population and Psi parameter

[AlexParo]

Hello all,
I conducted a 1 year research trough photo-identification of dolphins; the studied was designed for a capture-recapture experiment, primarily for abundance estimation.
Four independent areas were sampled, equal effort for all of them and data was pooled (1 ocassion = 4 samples: one for each area).
For simplicity, and since is a slow breeder animal with low mortality, I assumed a close population (although animals can move among areas and possibly off the study area). I used MARK, the Huggins models with heterogeneity and came up with a good estimation of parameters. I assume that the transient animals (captured just once) are animals that moves more and have lower probability of capture than the animals that showed a higher degree of fidelity, and that it is incorporated in the model by the heterogeneity of capture probabilities (Pledgers finite mixture model), which I believe give some flexibility in the geographic closure assumption.
But then, since I sampled four distinct geographic areas I was tempted to run a multi-state model for estimation of movement probabilities among areas. But since it is an extension of the CJS model, I have to consider the population as open and estimate survival probability now. Is it valid to do that for the sake of estimate the psi movement parameter?
Thanks in advance,
Alex

[claudiapenaloza]

If you have enough sampling data for it*... you can use a Closed Robust Design Multi-state with Huggins Heterogeneity
... and if you really want to, fix survival = 1.

*You would need to split up your occasions into at least two "sub-sampling" sessions and redo your encounter histories. If before you had 10 encounter occasions, now you would have 20 composed of 10 primary sampling periods each with 2 secondary sessions. An individual that had been sighted in the first occasion in your previous "model set up", may or may not have been sighted in both or only one of the secondary occasions of the first primary periods of your Robust Design set up (for more details see Chapter 15, page 562 of the Gentle Introduction http://www.phidot.org/software/mark/docs/book/).

hope that helps,
cp