Alternative to multi-season occupancy model for count data

33 views
Skip to first unread message

Vatsal Parikh

unread,
May 6, 2024, 4:51:48 PMMay 6
to unmarked
Hi all, I have a data for which I want to have different site covariates each season (land cover, population, etc.). I think that this could work well with a multi-season occupancy model (colext in unmarked), but I want to use count values (poisson distribution) rather than presence/absence. Is there a model in unmarked that could be used to achieve this goal? 

Marc Kery

unread,
May 6, 2024, 5:04:03 PMMay 6
to unmarked
Dear Vatsal,

the count-data analogue to the dynamic occupancy model is the Dail-Madsen model, or dynamic Nmix model. This is implemented in unmarked in the pcountOpen function. Can be VERY hard to fit models there when you have covariates. An alternative would be a year-stratified, static model (a.k.a., the "stacked data" approach), i.e., use function pcount() for stacked data and fit a random site effect to account for possible non-independence of the data in different years at the same site. Unless you are particularly interested in the parameters that govern the dynamics, this may be your best choice.

Best regards  --- Marc




From: unma...@googlegroups.com <unma...@googlegroups.com> on behalf of Vatsal Parikh <vat...@umich.edu>
Sent: Monday, May 6, 2024 22:33
To: unmarked <unma...@googlegroups.com>
Subject: [unmarked] Alternative to multi-season occupancy model for count data
 
Hi all, I have a data for which I want to have different site covariates each season (land cover, population, etc.). I think that this could work well with a multi-season occupancy model (colext in unmarked), but I want to use count values (poisson distribution) rather than presence/absence. Is there a model in unmarked that could be used to achieve this goal? 
--
*** Three hierarchical modeling email lists ***
(1) unmarked (this list): for questions specific to the R package unmarked
(2) SCR: for design and Bayesian or non-bayesian analysis of spatial capture-recapture
(3) HMecology: for everything else, especially material covered in the books by Royle & Dorazio (2008), Kéry & Schaub (2012), Kéry & Royle (2016, 2021) and Schaub & Kéry (2022)
---
You received this message because you are subscribed to the Google Groups "unmarked" group.
To unsubscribe from this group and stop receiving emails from it, send an email to unmarked+u...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/unmarked/95a79ceb-0cad-41b9-bd47-4f4ade55275fn%40googlegroups.com.
Reply all
Reply to author
Forward
0 new messages