Natural bases for the maintenance of homeothermic fauna in forests and mountain open spaces

Abstract

Terrestrial mammals and birds of temperate regions make a continuous effort to maintain muscular activity and metabolic rate at a constant body temperature, that being requested for their survival, growth and reproduction. Homeothermic regulation is particularly important in Italian forests and mountain open spaces, where temperature conditions vary considerably among seasons and are often critical during winter. The energy requirements, satisfied mainly by food, depend on food chains in the ecosystems. Most of the primary forest products (leaves and wood) are fundamental to the food chains for thermo-regulating species, provided defoliating and xylophagous insects act as intermediate consumers. The invasion of foreign species or populations can alter consumption rates and change ecological balances, thus creating problems in environmental management.
Many homeothermic organisms, especially birds, favour the dispersal of tree seeds, often with essential effects on the economy. The presence of streams and lakes in forests and mountain open spaces increases the availability of food resources for mammals and birds.