The count of observed response entries the fit's likelihood reads, which is
the sample size stats::AIC() and stats::BIC() form an information
criterion at. What one entry is follows the family's own response layout: a
surveyed (site, visit) cell for the occupancy families, a (site, band) count
for distance sampling, a (site, visit, source) cell for the integrated ones.
Usage
# S3 method for class 'tobs_fit'
nobs(object, ...)