Meeting Abstract

S11.2  Friday, Jan. 7  Directed aerial descent in canopy ants MUNK, Y*; YANOVIAK, S P; DUDLEY, R; UC Berkeley; University of Arkansas at Little Rock; UC Berkeley yonatanmunk@berkeley.edu

At least eight genera of tropical arboreal ants use directed aerial descent to return to their home tree trunk following a fall from the canopy. We presume that similar selection pressures act on these separate groups to maintain aerial performance, and in many cases these diverse genera of ants share broadly comparable natural history and morphological characteristics. Despite this, not all ants glide the same way: all known gliding ants in the subfamily Formicinae glide head-first, while ants in the subfamilies Myrmicinae and Pseudomyrmecinae glide backwards (i.e. with the abdomen leading). Wind tunnel studies conducted in the field reveal drastic differences in the behavioral modifications of posture by ants in these separate groups during gliding: while leg posture and abdominal flexion are important for all gliding ants, the roles of individual leg pairs with respect to whether they function as stabilizers or control surfaces for maneuvers vary significantly between forward and backward gliding ants. We will present a summary of the phylogenetic distribution of gliding in ants, both across genera and within the genera Cephalotes and Pseudomyrmex. We will furthermore present wind tunnel data documenting the behaviors and postures associated with stability and control during gliding in the backward gliding Cephalotes and the forward gliding Camponotus. Finally we will show, using dynamically scaled physical models, how changes in posture influence stability and control for both styles of gliding.