Bats coordinate sonar and flight behavior as they forage in open and cluttered environments.
Echolocating bats use active sensing as they emit sounds and listen to the returning echoes to probe their environment for navigation, obstacle avoidance and pursuit of prey. The sensing behavior of bats includes the planning of 3D spatial trajectory paths, which are guided by echo information. In this study, we examined the relationship between active sonar sampling and flight motor output as bats changed environments from open space to an artificial forest in a laboratory flight room. Using high-speed video and audio recordings, we reconstructed and analyzed 3D flight trajectories, sonar beam aim and acoustic sonar emission patterns as the bats captured prey. We found that big brown bats adjusted their sonar call structure, temporal patterning and flight speed in response to environmental change. The sonar beam aim of the bats predicted the flight turn rate in both the open room and the forest. However, the relationship between sonar beam aim and turn rate changed in the forest during the final stage of prey pursuit, during which the bat made shallower turns. We found flight stereotypy developed over multiple days in the forest, but did not find evidence for a reduction in active sonar sampling with experience. The temporal patterning of sonar sound groups was related to path planning around obstacles in the forest. Together, these results contribute to our understanding of how bats coordinate echolocation and flight behavior to represent and navigate their environment.
Program in Neuroscience and Cognitive Science, University of Maryland, College Park, MD 20742, USA. falk.ben@gmail.com.
Benjamin
B
Falk
Centre for Animal Movement, Evolutionary Ecology, Lund University, Ecology Building, SE-22362 Lund, Sweden.
Lasse
L
Jakobsen
Department of Biology, University of Southern Denmark, DK-5230 Odense M., Denmark.
Annemarie
A
Surlykke
Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD 21218, USA.
Cynthia F
CF
Moss
D000818:Animals; D001307:Auditory Perception; D002685:Chiroptera / Q000502:physiology*; D004455:Echolocation / Q000502:physiology*; D004777:Environment; D005426:Flight, Animal / Q000502:physiology*; D011235:Predatory Behavior / Q000502:physiology*; D013016:Sound
Echolocation; Flight behavior; Path planning; Spatial memory