Male Black-throated Tody-Tyrants hover back and forth in front of a female while making a “loud, whirring sound most likely produced by his rapid wing beats.” The courtship display and nesting behavior of these birds was described by Jenna McCullough and Gustavo Londoño in The Wilson Journal of Ornithology in 2017. http://www.bioone.org/doi/full/10.1676/16-122.1