PT  - JOURNAL ARTICLE
AU  - Olivier Gimenez
AU  - Emmanuelle Cam
AU  - Jean-Michel Gaillard
TI  - Individual heterogeneity and capture-recapture models: what, why and how?
AID  - 10.1101/120683
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 120683
4099  - http://biorxiv.org/content/early/2017/03/26/120683.short
4100  - http://biorxiv.org/content/early/2017/03/26/120683.full
AB  - Variation among and within individuals in life history traits is ubiquitous in natural populations. When affecting fitness-related traits like survival or reproduction, individual heterogeneity plays a key role in population dynamics and life history evolution. However, it is only recently that properly accounting for individual heterogeneity when studying population dynamics of free-ranging populations has been made possible through the development of appropriate statistical models. We aim here to review case studies of individual heterogeneity in the context of capture-recapture models for the estimation of population size and demographic parameters with imperfect detection. First, we define what individual heterogeneity means and clarify the terminology used in the literature. Second, we review the literature and illustrate why individual heterogeneity is used in capture-recapture studies by focusing on the detection of life-history trade-offs, including senescence. Third, we explain how to model individual heterogeneity in capture-recapture models and provide the code to fit these models (https://github.com/oliviergimenez/indhet_in_CRmodels). The distinction is made between situations in which heterogeneity is actually measured and situations in which part of the heterogeneity remains unobserved. Regarding the later, we outline recent developments of random-effect models and finite-mixture models. Eventually, we discuss several avenues for future research.