Covariate for multi-season occupancy model

[FTvM]

I am using a multi-season occupancy model with 2 primary sampling periods (2000 vs. 2006) for a black bear study. I want to use a habitat covariate for psi but that covariate (forest cover) has changed somewhat between the 2 sampling periods. Psi is estimated only for the first primary sampling period, whereas psi for the second sampling period is derived. So I am assuming that I should use forest cover conditions for the first primary sampling period as the covariate. Is that assumption correct?

Many thanks in advance for any insights on this!

Frank

[jhines]

Frank,

You can choose one of the other parameterizations in order to model psi(season). When you run a multi-season model, a list of alternate parameterizations appears as option radio-buttons. If you select the 2nd one, you can model psi for each season, and colonization, and the extinction parameter can be computed as a derived parameter. This allows you to put a covariate on each psi.

Jim

[FTvM]

Thanks Jim,

Are the alternate parameterizations you're referring to available in program PRESENCE ? I've been using MARK for this and I'm not sure I'm finding these options....

Frank

[gwhite]

Frank:
Yes, the other parameterizations are available in MARK. Select the option under the PIM menu choice for Change data type. There is the psi(t), gamma(t) parameterization, as well as the psi(t), epsilon(t) parameterization (in addition to the one you are currently using, psi(1), gamma(t), epsilon(t).

Gary