Why do so many animals excrete uric acid?
Animals have evolved to excrete nitrogenous waste in the form of uric acid for various reasons.
Birds, insects, and many reptiles excrete nitrogenous waste in the form of uric acid.
This is because they are unable to process urea due to their lack of a liver or other metabolic complexities.
Uric acid is a byproduct of the breakdown of purines.
The excretion process through uric acid eliminates up to 95% more nitrogen than urea.
Making it an excellent form for animals that do not have access to water as this increases the efficiency and reduces dehydration risks.
Evidence also suggests that birds can use their beaks or claws to create droplets from urine (urine-dipped grooming) which will then evaporate into dry leaves, where they consume them and extract nutrients such as salt and potassium in order to supplement what they find in food sources.
Insects need uric acid because it protects against predators due its acidic nature; the substance has been found on leaf littering forest floors with high insect populations when
