The experience of ecological analysis of morphophysiological features in small mammals. Part 2. Seasonal and age dynamics and individual variability of internal features

The dynamics of morphophysiological features over a life cycle of various small mammals on the northern periphery of the range is investigated. Juvenile small forest rodents of spring and summer generations are characterized by an extremely high pace of the generation development and growth, and a corresponding increase of the main internal features. Late generations members show smooth natural increase in the internal organs weight for the autumn, followed by a small decline in the winter, and fast maturing and growth accompanied with a sharp increase in morphophysiological indexes in the spring. The level of the internal features variability is very high, with spleen size having the greatest variability, followed by the size of thymus, adrenal glands, liver, heart, kidneys, and intestine length.