93-4 Wednesday, Jan. 6 14:15 Dog-fighting bees: 3D tracking of nest defense flight performance in eastern carpenter bees, Xylocopa virginica JACKSON, BE*; MUNSON-CATT, AC; Longwood Univ. email@example.com
Aggressive conspecific interactions offer unique opportunities to examine animal locomotion at the edge of the performance envelope, and may provide insight to mechanical limitations on, and energetic costs of, animal behavior. Female eastern carpenter bees (Xylocopa virginica ) are large pollinators that bore into wooden structures to build nesting tunnels, which they vigorously defend from other carpenter bees nesting in the same structure. We used three GoPro cameras to record (120 Hz) wild bee behavior as they built and defended nests in the author’s porch in Charlottesville, VA, USA. Videos were synchronized, calibrated, and analyzed using the new open-source Argus package and custom Matlab auto-tracking scripts to generate 3D paths. Over two recording days we recorded over 1200 flight paths, each lasting 1-10 s, by an estimated 25 individual bees. Paths were designated as non-chases or chases, which involved two to four bees at least temporarily in close proximity (< 20 cm) and following distinctly similar 3D trajectories. Non-chasing bees spent more time (~30%) than chasing bees (~10%) of their flights at near hovering speeds (< 0.5 ms-1). Bees involved in chases flew faster (median > 2 ms-1) and with greater acceleration (> 11 ms-2) than bees flying solo (1 ms-1; 4 ms-2). However, both chasing and non-chasing bees reached similar maximal horizontal velocities (10 ms-1). Surprisingly, some chases occurred at low speeds (< 2 ms-1), suggesting that not all chases were aggressive, or that velocity is not the principle factor in competitive flights during nest defense. Supported by LU-PRISM.