This bird is very well known for it's diverse vocalisations.Being non migratory it's body uses several tactics for thermoregulation. The Rufous-collared sparrow relies entirely on its kidneys for osmoregulation and ionoregulation. It is able to tolerate a wide range of salt intake despite lacking a salt gland, however the metabolic cost in energy is too great to maintain the necessary osmoregulatory processes for an extended period of time. As a result, the Rufous-collared sparrow tends not to inhabit marine environments such as salt marshes. Under conditions of higher salt intake, the mass of the kidney and heart can increase up to 20%. This response in organ size causes an increase in basal metabolic rate (BMR) by up to 30%. Kidney size is also affected by the amount of water available in the environment. In arid environments, the urine is more highly concentrated, and the kidneys tend to be smaller than in wetter environments.