Terrestrial locomotor behaviors of the big brown bat (Vespertilionidae: Eptesicus fuscus)

Although living bats (Mammalia: Chiroptera) demonstrate a wide variety of terrestrial behaviors and abilities, most research on terrestrial locomotor behaviors of bats has focused on those species known to be very terrestrially adept. Previous researchers have hypothesized that the terrestrial ability of bats is constrained by pelvic and hindlimb morphology, with gracile (type 1), intermediate (type 2), and robust (type 3) morphotypes corresponding to increasing levels of terrestrial competency. Here we present the first detailed report of the terrestrial locomotion and track morphology of the widespread North American vespertilionid Eptesicus fuscus. Although E. fuscus represents the intermediate pelvic and hindlimb morphotype (type 2), it is capable of performing a lateral sequence walk, common to quadrupedal vertebrates. The terrestrial locomotion behaviors of E. fuscus are similar to those reported for species of European vespertilionids, but it shows greater terrestrial ability than non-vespertilionid type 2 bats. Results further support a wider range of terrestrial ability in type 2 bats than has previously been understood.

Automated summary

Previous research suggested that the terrestrial ability of bats is limited by pelvic and hindlimb morphology. However, this study found that the widespread North American bat species, Eptesicus fuscus, has greater terrestrial ability than non-vespertilionid bats of the same morphotype and is capable of lateral sequence walk. These findings reveal a wider range of terrestrial ability in type 2 bats than previously understood.