FEEDING KINEMATICS OF PHYLLOMEDUSINE TREE FROGS

Previous studies have demonstrated that the phyllomedusine hylids poss ess highly protrusible tongues, a derived characteristic within the fa mily Hylidae. In the present study, the kinematics of the feeding beha vior of a phyllomedusine species, Pachymedusa dacnicolor, was analyzed using high-speed video (180 frames(-1)). Its behavior was compared wi th that of Hyla cinerea, a species with a weakly protrusible tongue, P . dacnicolor exhibits a faster rate of tongue protraction, a longer ga pe cycle and more variable feeding kinematics than H. cinerea. In addi tion, the tongue is used in a unique 'fly-swatter' fashion, to pin the prey to the substratum as the frog completes the lunge. The rapid ton gue protraction, extended gape cycle and fly-swatter action may have e volved in response to a diet of large, rapidly moving insects. In addi tion, several duration variables of the feeding cycle were greater for misses than for captures and drops, which suggests that sensory feedb ack rather than biomechanics controls gape cycle duration.