Date of Award


Degree Type


Degree Name

Master of Science




Brock Fenton

Second Advisor

Beth MacDougall-Shackleton

Third Advisor

David Sherry


Free-flying insectivorous bats occasionally collide with stationary objects that they should easily detect. These collisions often occur when lights are on suggesting that bats that collide may attend to visual sensory input over echolocation. To investigate the role of visual cues on the collisions of free-flying Myotis lucifugus with stationary objects, I set up obstacles at an Ontario swarming site. I used combinations of light intensities, obstacle fabrics that were not visually alike, and conspecific distress calls to verify that the bats in my study were not distracted by distress calls, and appeared to orient by vision when visual cues were available. Initially bats collided most in the light and least with luminous visible fabrics, but the order of collisions changed in mid to late August, coincident with the start of the second phase of swarming. My findings suggest that visual cues are more important for free-flying bats than previously recognized, and further controlled field studies are necessary to understand the integration of multi- sensory modalities during orientation.



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