Approximately, seven percent of the body's blood is in the capillaries which continuously exchange substances with the liquid outside these blood vessels, called interstitial fluid. This dynamic displacement of materials between the interstitial fluid and the blood is named capillary exchange.pproximately, seven percent of the body's blood is in the capillaries which continuously exchange substances with the liquid outside these blood vessels, called interstitial fluid. This dynamic displacement of materials between the interstitial fluid and the blood is named capillary exchange.
The Base Diet for Birds: Food That Is Balanced. In the wild, birds eat a vast variety of foods: seeds, nuts, grasses, flowers, fruits, insects, the list goes on. The change in seasons brings new types of foods, and birds nourish themselves on whatâs available.
How to Feed a Robin Bird. Robins are more difficult to feed than most wild birds. They rarely eat birdseed, preferring protein found in worms and other invertebrates. Robins that winter in a northern climate have a hard time finding worms. Robins also have a sweet tooth and enjoy fruit, even sweet cakes.