Air Force Office of Scientific Research (AFOSR) 2012

Award Date: May 2012

Summary

Professor Robert Olberg has received a supplemental funding award in the amount of $21,521 from the Air Force Office of Scientific Research (AFOSR) to support his research project entitled “The Neuronal Control of Flying Prey Interception in Dragonflies.” Specifically, this supplement supported PI Olberg's collaborative study to obtain high-speed video recordings to reconstruct, in 3D, flight trajectories of an aerial predator (killer fly: C. attenuata) and its potential prey (small flying insects such as fungus gnats, fruit flies, etc.) in their "wild" environment (large greenhouses in Spain).

Abstract

The supplemental award supports a study to further advance PI Olberg's research and investigations into the dragonfly brain, specifically how visual information about the prey’s position and velocity are transformed into steering instructions, directing the dragonfly’s flight trajectory to a point of future intersection with the prey’s trajectory. 

Background:  The predatory behavior of both male and female killer flies (C. attenuata) resembles that of larger insect predatory species, such as dragonflies. For example, killer flies are territorial sit and wait predators, that not only go back to their perch after prey capture (Narhardiyati and Bailey, 2005), but also defend their territory. Moreover, analysis of
preliminary trials confirmed that such predatory behavior is triggered by movement of the prey (Narhardiyati and Bailey, 2005) and that killer flies may be able to intercept their prey, but switch to a pursuit strategy whenever appropriate. The behavioral correlates between dragonflies and killer flies make these two groups especially useful for a comparative study.

Goal:  To reconstruct, in 3D, the predatory flight trajectory of the killer fly and its prey during the predatory attacks in the wild to start answering the following questions:

  1. Do killer flies indeed display an interception trajectory? Interception trajectories have been shown to occur in other dipterans, such as hoverflies. However, the closest relatives to the killer flies (Musca) employ a chase strategy to catch up with conspecific.
  2. Do killer flies exhibit head movements before take-off as displayed in dragonflies? If so, is it likely that killer flies use motion parallax for prey distance estimation at the time of prey detection?
  3. At what distance can prey elicit a behavioral response through: a. movement of the head and b. chase initiation?
  4. If killer flies do exhibit an interception strategy, under which conditions would killer flies switch to a pursuit strategy?
  5. Killer flies exhibit sexual dimorphism; male killer flies are significantly smaller than female killer flies. Is this size difference reflected in their flight trajectories?