Write a 1,050- to 1,400-word paper analyzing avian physiological adaptations. In your paper, address the following:
Discuss circulatory, respiratory, and excretory system adaptations. Explain temperature regulation and metabolism in birds. Examine how birds maintain water reserves. Analyze how environmental factors shaped the evolution of these adaptations. Describe examples of these adaptations in different species. Examine how adaptability to environment has contributed to the success of flightless birds. Cite at least three primary scholarly references. Format your paper consistent with APA guidelines.