How Do Birds Keep Their Chicks Hydrated? Q. How do seed-eating birds keep their chicks hydrated? And how can chicks in birdhouses survive high temperatures? A. Birds that feed exclusively on seeds can produce water internally, but they provide their chicks with water from other sources, said Kevin J. McGowan, the instructor for the Cornell Lab of Ornithology's home study course in bird biology. "Most birds, even those that eat primarily seeds as adults, feed their chicks insects, which contain water," Dr. McGowan said. Some species, like crows, dunk food in water before feeding it to the chicks. As adults, they "use primarily metabolic water, which is produced by cellular respiration," he said. "Water is a byproduct of the breakdown of carbohydrates, fats and proteins, and some birds can exist completely on that source alone" - though most do not. As for heat tolerance in the nest or birdhouse, he said, chicks "can handle the heat better than you can, especially if they aren't yet covered with feathers, which trap heat." The normal body temperature for most small birds is about 105 degrees Fahrenheit, Dr. McGowan said. Below that, the bird needs to conserve or create heat, and above that, it needs to dump heat. Young nestlings cannot regulate their body temperature, he said, so parents try to keep them at the optimum temperature by brooding the chicks or by shading open-cup nests.