Single survey per transect

[Rob Guldemond]

Dear all,

We have a >20 year long-term monitoring database of several taxa in regenerating forests. Every site is obviously one year older each year after rehabilitation (a covariate), and we collected information on species presence and abundance each year. Our problem is, however, that we have a different number of replicates per regenerating site allocated randomly across the site with the same sampling point never surveyed consecutively, and that each replicate is only surveyed once (no repeated visit per sampling occasion, per season, or per year). For instance, searching for millipedes on the forest floor require us to remove them individually from the transects to avoid double counting (sometimes >1/10/100/1000 individuals per transect depending on the species) and we therefore cannot re-survey each sampling point (transect). Do you maybe have any thoughts on which/what approach (both in modeling or software references) we can use to calculate single species detectability, occupancy, colonisation, and extinction rates of these regenerating forest sites? Our interest here is on a specific millipede that has recently been listed as a red data species for the area.

Kind regards and thank you in advance,
Rob