Where and when are they?
Site occupancy
Occupancy asks where a species lives. Not hearing a species doesn't mean it isn't there: it may have been quiet, too far from the recorder, or drowned out by wind or rain.
How it works
Recording at many sites on repeated days lets us estimate two things separately: how likely a species is to be heard when it is present, and how likely it is to be present at all. That gives a probability for every site, including the ones where it was never heard.
What you get
- Probability of presence at each site, with a confidence interval
- How detectable each species is
- Change across seasons or years when repeated
Good for
- Tracking the spread or recovery of a species
- Showing likely absence, for example after pest eradication
- Comparing managed and unmanaged areas
Study design
Needs enough sites and repeat days for the species. We check this with you before recorders go out.