I have not looked into that. Thank you so much!

I would second this approach and possibly extend this to an abundance "N-mixture" model. Each 15 min image could be considered a 'visit' and covariates such as tide and weather used to describe detectability, while habitat covariates describe the 'haul out sites'. 

There are several assumptions to meet about independence that should be considered and additional analyses that can account for spatial autocorrelation.

A good read is the documentation and vignettes for the R package 'Unmarked'. If you want a deeper understanding the two volumes of 'Applied Hierarchical Modeling in Ecology' by Kery and Royle will answer all your questions. There is also a google group for Unmarked with plenty of helpful contributors if you need help

Thank you very much!

I think this is a possibility, but we have some cameras that are further away and individual identification becomes difficult.  We have 9 sites, but seals have ever only shown up on 8 of them through our 3 seasons of data collection. Cameras are out from October-May respectively, but are not installed/removed on the exact same date every season. and yes there are images with no seals between images with seals.

Absolutely, I am happy to provide it. Our objectives are 1) to improve the understanding of local and seasonal haul-out patterns, and the numbers of seals hauled out during daylight hours; 2) to investigate any haul-out patterns in relation to environmental factors. 

We had 10 different cameras set up at two different survey areas (8 at one location and 2 at another). We are studying the two survey areas separately. At one of the locations there are 8 different survey sites within the area where seals haul-out, at the other location, there are 2 different survey sites within the area. 

So far we have completed 3 survey seasons as well. 

Let me know if there is anything else I can provide!