Animals and Environments: Resisting Schisms in Comparative Physiology and Biochemistry

Molecules to migration: pressures of life

The highly successful Fourth International Conference in Africa for Comparative Physiology and Biochemistry (ICA-CPB) was held in the Maasai Mara National Reserve in July 2008. The theme of the meeting was "Molecules to Migration: Pressures of Life." To enhance the theme, the venue and timing of the meeting were chosen to coincide with the arrival of approximately 1.4 million wildebeest on their annual migration from the Serengeti National Park in Tanzania. Like the three previous ICA-CPB meetings, the discussion topics and the resulting collection of synthesia presented here were very diverse. The articles in this special collection reflect the authors' interest in broadening our understanding of the field of comparative physiology and biochemistry and their commitment to engaging in global research with international colleagues. These articles are brief, synthetic reviews integrating information presented at and inspired by the meeting. From seasonal migration and reproduction in birds, to cardiovascular system development in vertebrates, to strategies for hypoxia survival, papers range from specific to broad interactions. What they all have in common: they increase our understanding of how animals are affected by and respond to the pressures of life.

Habitat and year-to-year variation in haemoglobin concentration in nestling blue tits Cyanistes caeruleus

Nutrition during the time spent at the nest is critical for the development of the body condition in altricial birds, including nestling blue tits (Cyanistes caeruleus). Trophic conditions tend to be variable in time and space, which should influence the physiological condition of growing birds. In this paper, we consider haemoglobin concentration as a general indicator of chick physiological condition. Its variation is both consistent within broods and indicative/prognostic of survival from the moment of hatching to fledging. We show that haemoglobin concentration of nestling blue tits is on average higher in years and habitats characterised by rich abundance of caterpillars than under poor caterpillar availability. Haemoglobin seems to quite exactly reflect even relatively subtle differences in trophic conditions.