Bats and birds as viral reservoirs: A physiological and ecological perspective

Abstract

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.

Keywords: Bat; Bird; Flight; Immunology; Physiology; Viral transmission.

Graphical abstract

Fig. 1

The relationships between body mass and life span in birds (n = 1660), bats (n = 260), and non-flying mammals (n = 2293). Birds (P < 0.001) and bats (P < 0.001) have significantly longer lifespans than non-flying mammals when controlled for body mass in a general linear model. Black lines around the fitted line are the 95% confidence intervals for each taxon. Body mass and lifespan data for each group were taken from Myhrvold et al. (2015).