Data from: Estimating latent individual demographic heterogeneity using structural equation models

Understanding the drivers of fitness is a key goal of population and
evolutionary ecology. However, measuring individual variation in
demographic components in imperfectly observed populations of wild
organisms is extremely challenging. Recent research has demonstrated that
estimates of fixed individual variation in Bernoulli variables (e.g.,
survival, breeding propensity) are often unreliable in the face of
imperfect detection and small sample sizes. Thus, we demonstrate the use
of structural equation modeling approaches to simultaneously estimate
latent variation in demographic performance, and link said variation to
individual demographic components. We demonstrate the use of this approach
with 30+ year capture-recapture datasets collected on two passerine
species (White-throated dipper, Cinclus cinclus, and Pied flycatcher,
Ficedula hypoleuca), and pied flycatcher, \textit{Ficedula hypoleuca}),
and simultaneously estimate latent variation in individual quality and
age-specific variation in demographic components. We found senescent
decline in survival and fecundity in both species, and demonstrated strong
among-individual heterogeneity in demographic performance. Notably,
residual reproductive value of older individuals of higher quality was
greater than younger individuals of reduced and average quality. We
demonstrate that this approach may be useful in a variety of situations,
discuss its limitations, and make suggestions for future research. To
reproduce these analyses, we provide two capture-recapture datasets
(dipper and flycatcher) collected over decades in Switzerland. We also
provide relevant code for analyses, as well as code for data simulation.