Factors influencing the radiative surface temperature of grey seal (Halichoerus grypus) pups during early and late lactation

The aim of this study was to examine the variation in body surface temperature of grey seal (Halichoerus grypus) pups throughout lactation in response to different environmental conditions. Radiative surface temperatures (T r, °C) of pups were measured on the Isle of May (56°11′N, 02°33′W), southeast Scotland from 29 October to 25 November 2003. Records were obtained from a total of 60 pups (32 female and 28 male) from three different pupping sites during early and late lactation. Pups were sheltered from high wind speeds but air temperature, humidity and solar radiation at pupping sites were similar to general meteorological conditions. The mean T r of all pups was 15.8°C (range 7.7–29.7°C) at an average air temperature of 10.2°C (range 6.5–13.8°C). There was no difference in the mean T r of pups between early and late lactation. However, the T r varied between different regions of the body with hind flippers on average 2–6°C warmer than all other areas measured. There was no difference in mean T r of male and female pups and pup body mass did not account for the variation in T r during early or late lactation. Throughout the day there was an increase in the T r of pups and this explained 20–28% of the variation in T r depending on stage of lactation. There was no difference in the mean T r of pups between pupping sites or associated with different substrate types. Wind speed and substrate temperature had no effect on the T r of pups. However, solar radiation, air temperature and relative humidity accounted for 48% of the variation in mean T r of pups during early lactation. During late lactation air temperature and solar radiation alone accounted for 43% of the variation in T r. These results indicate that environmental conditions explain only some of the variation in T r of grey seal pups in natural conditions. Differences in T r however indicate that the cost of thermoregulation for pups will vary throughout lactation. Further studies examining intrinsic factors such as blubber thickness and activity levels are necessary before developing reliable biophysical models for grey seals.

Health assets and active lifestyles during preadolescence and adolescence: highlights from the HBSC/WHO health survey and implications for health promotion

The present chapter discusses the assets model as a theoretical approach to the study of health behavior and health promotion. The model emphasizes people’s talents, competences, and resources. In this chapter, a health asset is defined as any factor or resource that maximizes the opportunities for individuals, local communities, and populations to attain and maintain health and well-being. This perspective expands and complements the current medical model as it focuses on the development of a sense of empowerment in community members to prevent and manage their own health. Therefore, in this chapter we address the concepts of salutogenesis, social support, resilience, coping, self-regulation, social capital, and personal and social competence, which are central to the development of individuals’ potential to manage and savor their own health, creating the conditions for self-fulfillment. Additionally, we demonstrate how the assets model guides the study of children’s and adolescents’ health in the Portuguese Health Behaviour in School-aged Children study (www.hbsc.org), concentrating on areas such as active lifestyles and quality-of-life perception. Finally, we present a roadmap for action that emphasizes the need to identify the factors that make children and adolescents happy and healthy individuals, while minimizing risks and problems they naturally encounter throughout their development. We also argue for the need to involve young people in discussions concerning their health and health promotion practices, focusing on the development of talents, capabilities, and positive expectations for the future.