Statistics Across Campuses: Subbash Lele -- Dealing with detection error in site occupancy and abundance surveys:

Dealing with detection error in site occupancy and abundance surveys: what can we do
with a single survey? 

Date: 04 December 2020, Friday 

Time: 10am AEDT 

Speaker: Prof Subbash Lele (University of Alberta) 

Abstract: 

Site occupancy probabilities and abundance of target species are commonly used in
various ecological studies.  Detection error introduces bias in the estimators of site
occupancy.  Existing methods for estimating occupancy probability in the presence of
detection error use replicate surveys.  These methods assume either population closure,
i.e.  the site occupancy status remains constant across surveys or a structured
dependence across surveys.  The practical difficulties with replicate surveys are well
known.  Statistically, the closure assumption is seldom satisfied and the dependence
structure can be difficult to model.  The cost of replicate surveys can be prohibitive
and they may be logistically prohibitive.  

Given these practical difficulties, we ask the question: what can we do with a single
survey? We discuss the conditions under which one can estimate the regression models for
detection and occupancy/abundance.  We illustrate that the conditions are not
excessively restrictive.  On the other hand, aside from being difficult to justify, the
effect of violation of the assumption of close population or dependence structure can be
substantial.  As is the case for most statistical methods, there are pros and cons to
both single and replicate survey methods.  The appropriate choice depends on the
particular situation on hand.  

References: 

Lele, S.  R., Moreno, M., & Bayne, E.  (2012).  Dealing with detection error in site
occupancy surveys: what can we do with a single survey? Journal of Plant Ecology, 5(1),
22-31.  

Sólymos, P., & Lele, S.  R.  (2016).  Revisiting resource selection probability
functions and single-visit methods: Clarification and extensions.  Methods in Ecology
and Evolution, 7(2), 196-205.  

Link: https://au.bbcollab.com/guest/fcf219c74ac743e89565a9e6e8d349a9