Modeling Recruitment of Birth Cohorts to the Breeding Population: A Hidden Markov Model Approach

摘要: Long-term capture-recapture studies provide an opportunity to investigate the population dynamics of long-lived species through individual maturation and adulthood and/or time. We consider data collected on cohorts female grey seals (Halichoerus grypus) born during 1990s later observed breeding Isle May, Firth Forth, Scotland. Female can live for 30+ years but display variability in their rates so recruit into across a range ages. Understanding partially hidden process by which individuals transition from immature members, particular identification any changes this time, are important understanding factors affecting species. Age-structured models explicitly relate recruitment, other demographic parameters interest, age To account monitoring several birth we age-structured model that incorporates specific cohort-structure. Within focus estimation distribution recruitment at colony. process, identifying or trends will offer insight year effects, give more realistic profile current UK seal model. The use Markov provides intuitive framework following evolution true underlying states individuals. breaks down different processes system: population; survival; associated observation process. This specification results explicit compact expression with efficiency fitting. Further, naturally leads extensions complex models, example separation first-time return breeders, relatively simple mathematical structure