Abstract <p>Field and laboratory studies were performed to assess the age-related characteristics of the amino acid spectrum of blood plasma in pond bats (<i>Myotis dasycneme</i> Boie, 1825) from natural populations of the Urals. A comparative analysis of the free amino acid pool content in the blood plasma of adult and juvenile (subadult) female pond bats during the summer period of their annual life cycle is presented for the first time. The plasma amino acid pool of the pond bat, regardless of age, comprised 22 amino acids and their derivatives, including the full spectrum of functionally significant essential amino acids: threonine, valine, lysine, leucine, isoleucine, methionine, phenylalanine, arginine, histidine, and tryptophan. An assessment was made of the interconnected role of the blood system and free amino acids in animals in shaping the species adaptive strategy in response to both seasonal variation in the annual life cycle and pathogens of natural and zoonotic significance.</p>