All stress-related hormones were significantly elevated during physical examination. Plasma ACTH concentrations were most increased, 5–10-fold, during physical examination, whereas cortisol and aldosterone showed 2–4-fold elevations. Stress response analytes measured during the
WCS did not differ significantly from baseline concentrations. “
“Simple Bayesian statistical Obeticholic Acid mouse models are introduced to estimate the proportion of identifiable individuals and group sizes in photographic identification, or photo-ID, studies of animals that are found in groups. The models require a simple random photographic sampling of animals, where the photographic captures are treated as sampling with replacement within each group. The total number of images, including those that cannot be identified, and the number of images that contain identifiable individuals are used to make inference
about the selleck compound proportion of identifiable individuals within each group and as the population when a number of groups are sampled. The numbers of images for individuals within each group are used to make inference about the group size. Based on analyses of simulated and real data, the models perform well with respect to accuracy and precision of posterior distributions of the parameters. Widths of posterior intervals were affected by the number of groups sampled, sampling duration, and the proportion of identifiable individuals in each group that was sampled. The structure of the models can accommodate covariates, which may affect photographic efficiency, defined in this study as the probability of photographically capturing individuals. “
“We conducted a 15 yr mark-resight study of branded California sea lions (Zalophus californianus) 上海皓元 at San Miguel Island, California, to estimate age-specific recruitment and natality of the population. We used the Schwarz and Stobo model to estimate sighting, survival, recruitment, timing of births, abundance, and age-specific
natality from sighting histories of 1,276 parous females. The advantage of this approach was that the reproductive status of females did not have to be known for all females of reproductive age. Probability of recruitment into the reproductive population began at age 3 or 4, peaked between ages 5 and 7, and slowly declined. Age-specific natality was similar for ages 4–16 but declined after age 17, suggesting that reproductive senescence occurs in older females. The average annual natality for parous females 4–16 yr of age was 0.77 (SE = 0.03); natality declined to 0.56 (SE = 0.10) for parous females 17–21 yr of age. Natality for both age classes was reduced during El Niño conditions by 24% and 34%, respectively. In addition to reducing natality, El Niño events may result in a delay of recruitment if females experience El Niño conditions before they turn 4 yr of age.