single-season analysis with trap-dependence

[vincenzogervasi]

Hi,
I am running a single-season occupancy analysis, in which I have a very strong trap-dependence (trap-happiness): after a species is detected in a given cell for the first time, its probability to be re-detected in the same cell is much higher. I need to separate the probability of first detection from all the others. Any advice on how to model this with PRESENCE?

Thanks,
Vincenzo.

[Alan Dextrase]

Hello Vincenzo,

You could include a binary sampling covariate that equals 0 if there are no previous detections and equals 1 if the species has been previously detected in the sampling unit. For example if you had four surveys and detected the species in the first survey at a site, the covariate would be 0111; first detection in the second survey would be 0011, and so on. You could then compare to models without the covariate to examine the effect.

Alan

[vincenzogervasi]

Thanks Alan,
this is neat idea. I'll try it.

Vincenzo.