Rachel McCrea and co-authors from St Andrews and Edinburgh have published a paper on modelling the recruitment process of gray seals.<\/p>\n
The full paper is available open access here: https:\/\/www.frontiersin.org\/articles\/10.3389\/fevo.2021.600967\/full<\/p>\n
Modeling Recruitment of Birth Cohorts to the Breeding Population: A Hidden Markov Approach<\/strong><\/p>\n Worthington, King, McCrea, Smout and Pomeroy<\/p>\n Long-term capture-recapture studies provide an opportunity to investigate the population dynamics of long-lived species through individual maturation and adulthood and\/or <\/p>\n","protected":false},"excerpt":{"rendered":" Rachel McCrea and co-authors from St Andrews and Edinburgh have published a paper on modelling the recruitment process of gray seals. The full paper is available open access here: https:\/\/www.frontiersin.org\/articles\/10.3389\/fevo.2021.600967\/full Modeling Recruitment of Birth Cohorts to the Breeding Population: A Hidden Markov Approach Worthington, King, McCrea, Smout and Pomeroy Long-term capture-recapture studies provide an opportunity […]<\/p>\n","protected":false},"author":40696,"featured_media":932,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[],"_links":{"self":[{"href":"https:\/\/blogs.kent.ac.uk\/seak\/wp-json\/wp\/v2\/posts\/931"}],"collection":[{"href":"https:\/\/blogs.kent.ac.uk\/seak\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.kent.ac.uk\/seak\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.kent.ac.uk\/seak\/wp-json\/wp\/v2\/users\/40696"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.kent.ac.uk\/seak\/wp-json\/wp\/v2\/comments?post=931"}],"version-history":[{"count":1,"href":"https:\/\/blogs.kent.ac.uk\/seak\/wp-json\/wp\/v2\/posts\/931\/revisions"}],"predecessor-version":[{"id":933,"href":"https:\/\/blogs.kent.ac.uk\/seak\/wp-json\/wp\/v2\/posts\/931\/revisions\/933"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blogs.kent.ac.uk\/seak\/wp-json\/wp\/v2\/media\/932"}],"wp:attachment":[{"href":"https:\/\/blogs.kent.ac.uk\/seak\/wp-json\/wp\/v2\/media?parent=931"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.kent.ac.uk\/seak\/wp-json\/wp\/v2\/categories?post=931"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.kent.ac.uk\/seak\/wp-json\/wp\/v2\/tags?post=931"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\ntime. We consider capture-recapture data collected on cohorts of female gray seals
\n(Halichoerus grypus) born during the 1990s and later observed breeding on the Isle
\nof May, Firth of Forth, Scotland. Female gray seals can live for 30+ years but display
\nindividual variability in their maturation rates and so recruit into the breeding population
\nacross a range of ages. Understanding the partially hidden process by which individuals
\ntransition from immature to breeding members, and in particular the identification of
\nany changes to this process through time, are important for understanding the factors
\naffecting the population dynamics of this species. Age-structured capture-recapture
\nmodels can explicitly relate recruitment, and other demographic parameters of interest,
\nto the age of individuals and\/or time. To account for the monitoring of the seals from
\nseveral birth cohorts we consider an age-structured model that incorporates a specific
\ncohort-structure. Within this model we focus on the estimation of the distribution of
\nthe age of recruitment to the breeding population at this colony. Understanding this
\nrecruitment process, and identifying any changes or trends in this process, will offer
\ninsight into individual year effects and give a more realistic recruitment profile for the
\ncurrent UK gray seal population model. The use of the hidden Markov model provides an
\nintuitive framework following the evolution of the true underlying states of the individuals.
\nThe model breaks down the different processes of the system: recruitment into the
\nbreeding population; survival; and the associated observation process. This model
\nspecification results in an explicit and compact expression for the model with associated
\nefficiency in model fitting. Further, this framework naturally leads to extensions to more
\ncomplex models, for example the separation of first-time from return breeders, through
\nrelatively simple changes to the mathematical structure of the model.<\/p>\n