I'm having some trouble getting my data into the correct format for a polygon detector in SECR (in R). I'm hoping to use this package as a way to estimate current densities of lions and cheetahs in a protected area in east Africa. We regularly conduct area searches throughout regions in the reserve and identify these animals based on individual markings. From this data collection, I have (up to) twice daily observations of animals that were seen in these search areas. Additionally, there are times when we go out but do not see any of our animals that have been "marked."
My question is two-fold, but both relate to the data formatting for polygon search detectors. I have the polygon file working well, but cannot seem to get my capture file in the correct format. The correct columns should be "Session", "ID", "Occasion", "X", and "Y." However, I'm not exactly sure what the difference between Session and Occasion are in this case. If I have 30 different times in which we searched the polygon, does that mean that I'd have 30 sessions or 30 occasions? Similarly, is effort taken into account when a polygon was searched but no animals were sighted?
Thank you very much for your help. I really appreciate it!