Hello -
I am trying to obtain a density estimate using secrlinear across three sampling sessions(years). I am also combining detector types - I used a camera trap array and human observations. Since the camera traps "work" around the clock while human observers worked 5-6 hours per shift I want to specify varying usage across the trap array (29 locations) for each session and for each occasion. Sampling periods within a year (session) ranged from 111 - 251 days (occasions), and not every site was in use each session. The camera trap sites were used multiple days in a row, whereas human observation stations were used sporadically.
I have the data files across all traps for each session (one for each year), but it is not clear to me if I can or how to incorporate the varying usage files into the secr capthist file. Or is it called in the secr.fit command?
from the usage help file:
usage(object) <- value (This command only appears to allow one varying usage file at a time, and I cannot use it to assign other names, such as for each session in my data set)
For replacement of usage, various forms are possible for value
...
- a vector of R+1 values where R is the number of sessions in a multi-session object and elements 2..R+1 correspond to the numbers of occasions S1, S2,... in each session
(so in my case R = 3; but this calls for 4 values, again in my case: 3 111 112 251
This does not allow for varying usage of a trap site within a session)
So is it possible to use multiple sessions with varying usage/effort within each session?
Or should i run each year separately?
Thanks in advance!