Occupancy and imperfect species detection
Failure to detect a species does not establish absence.
Key knowledge
Failure to detect a species does not establish absence. In a simple closed-site model with occupancy probability ψ and independent visit detection probability d conditional on presence, the probability of at least one detection in K visits is ψ[1−(1−d)^K]. One visit observes ψd and cannot by itself separate occupancy from detectability.
Values and equations
Pr(at least one detection)=ψ[1−(1−d)^K]
- ψ
- site occupancy probability 1
- d
- per-visit detection probability conditional on presence 1
- K
- number of repeated visits with the stated model 1
Conditions and scope
- No false positives, unchanged occupancy during the repeat visits, fixed conditional d and conditional independence; K is a positive integer.
- Inference needs a suitable repeat-visit design and identifiable model. Unequal detectability, covariates, dependent observations or changing occupancy need broader models; occupancy is a presence probability, rather than organism abundance.
Sources · 1
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
Evidence and review
Read the original-author study abstract's nondetection/occupancy distinction and model objective. The displayed simplified repeat-visit probability is a disclosed derivation using conditional independent Bernoulli trials, not a claim to have inspected all eight paper pages or its full likelihood. Excluded the study's model-specific numerical accuracy and animal estimates.
2026-10-10 · Independent AI editorial review: All six exact compact records, equations/variables/conditions and eighteen origin edges, plus actual bounded primary sections/abstracts listed below. This is independent AI editorial review, not laboratory validation or whole-Biology revalidation. Receipt: biology-quantitative-independent-review.1.
Entry details
Permanent link to this entry ↗- Record identity
- uni-bio-occupancy-detection
- Revision
- core.1
- Structured reference record
- University core expansion