Nicholas School of the Environment, Duke University, Durham, North Carolina, United States of America.
PLoS One. 2013 Jun 6;8(6):e64166. doi: 10.1371/journal.pone.0064166. Print 2013.
Body condition is an indicator of health, and it plays a key role in many vital processes for mammalian species. While evidence of individual body condition can be obtained, these observations provide just brief glimpses into the health state of the animal. An analytical framework is needed for understanding how health of animals changes over space and time.Through knowledge of individual health we can better understand the status of populations. This is particularly important in endangered species, where the consequences of disruption of critical biological functions can push groups of animals rapidly toward extinction. Here we built a state-space model that provides estimates of movement, health, and survival. We assimilated 30+ years of photographic evidence of body condition and three additional visual health parameters in individual North Atlantic right whales, together with survey data, to infer the true health status as it changes over space and time. We also included the effect of reproductive status and entanglement status on health. At the population level, we estimated differential movement patterns in males and females. At the individual level, we estimated the likely animal locations each month. We estimated the relationship between observed and latent health status. Observations of body condition, skin condition, cyamid infestation on the blowholes, and rake marks all provided measures of the true underlying health. The resulting time series of individual health highlight both normal variations in health status and how anthropogenic stressors can affect the health and, ultimately, the survival of individuals. This modeling approach provides information for monitoring of health in right whales, as well as a framework for integrating observational data at the level of individuals up through the health status of the population. This framework can be broadly applied to a variety of systems - terrestrial and marine - where sporadic observations of individuals exist.
身体状况是健康的一个指标，它在哺乳动物的许多重要生理过程中起着关键作用。虽然可以获得个体身体状况的证据，但这些观察结果只是动物健康状况的短暂 glimpse。需要有一种分析框架来理解动物的健康状况如何随时间和空间而变化。通过了解个体健康，我们可以更好地了解种群的状况。这在濒危物种中尤为重要，因为关键生物功能的中断可能会迅速将动物群体推向灭绝。在这里，我们构建了一个状态空间模型，该模型提供了运动、健康和生存的估计。我们将 30 多年来的身体状况和另外三个视觉健康参数的照片证据，以及调查数据，整合在一起，以推断随着时间和空间的变化，真实的健康状况。我们还包括了生殖状态和纠缠状态对健康的影响。在种群水平上，我们估计了雄性和雌性的差异运动模式。在个体水平上，我们估计了每个月动物可能的位置。我们估计了观察到的和潜在的健康状况之间的关系。身体状况、皮肤状况、虹吸管上的寄生虫和耙痕的观察都提供了真实潜在健康状况的衡量标准。个体健康的时间序列突出了健康状况的正常变化，以及人为压力源如何影响个体的健康，最终影响个体的生存。这种建模方法为监测南方露脊鲸的健康状况提供了信息，同时也为在个体水平上整合观测数据以及种群健康状况提供了框架。该框架可以广泛应用于各种系统，包括陆地和海洋系统，在这些系统中存在个体的零星观察。
