The birds (class Aves) and bats (order Chiroptera, class Mammalia) are well known natural reservoirs of a diverse range of viruses, including some zoonoses. The only extant volant vertebrates, bats and birds have undergone dramatic adaptive radiations that have allowed them to occupy diverse ecological niches and colonize most of the planet. However, few studies have compared the physiology and ecology of these ecologically, and medically, important taxa. Here, we review convergent traits in the physiology, immunology, flight-related ecology of birds and bats that might enable these taxa to act as viral reservoirs and asymptomatic carriers. Many species of birds and bats are well adapted to urban environments and may host more zoonotic pathogens than species that do not colonize anthropogenic habitats. These convergent traits in birds and bats and their ecological interactions with domestic animals and humans increase the potential risk of viral spillover transmission and facilitate the emergence of novel viruses that most likely sources of zoonoses with the potential to cause global pandemics.

鸟类（鸟纲）和蝙蝠（翼手目，哺乳动物纲）是众所周知的多种病毒（包括一些人畜共患病）的天然宿主。唯一现存的展翅脊椎动物、蝙蝠和鸟类经历了剧烈的适应性辐射，使它们能够占据不同的生态位并在地球的大部分地区定居。然而，很少有研究比较这些生态学和医学上重要的分类群的生理学和生态学。在这里，我们回顾了鸟类和蝙蝠的生理学、免疫学、飞行相关生态学的趋同特征，这些特征可能使这些分类群成为病毒库和无症状携带者。许多鸟类和蝙蝠物种非常适应城市环境，并且可能比不在人为栖息地定居的物种携带更多的人畜共患病原体。