Meeting Abstract

47.4  Tuesday, Jan. 5  Sequence analysis of aggressive interactions between male dyads of stalk-eyed flies EGGE, A.R.*; BRANDT, Y; SWALLOW, J.G.; The University of South Dakota, Vermillion; The University of South Dakota, Vermillion; The University of South Dakota, Vermillion aegge@usd.edu

Stalk-eyed flies of the species Teleopsis dalmanni are sexually dimorphic with males exhibiting extreme hypercephaly relative to females. In males, eye-span is highly correlated to body length and is an indicator of relative strength and condition. Previous studies have suggested that males use eye stalk length to assess their opponent’s fighting ability during resource competition. Such studies have investigated the effects of morphology on the outcome of these agonistic interactions; however, we still lack a detailed examination of the behavior that winners and losers display while competing. Sequential analysis of aggressive behavior reveals behavioral transition probabilities and may provide insights into the significance of such behaviors. In this experiment, we placed two males in a divided arena and starved them for 24-hours. Once starved, the partition was removed and a drop of high-quality food was added. Flies were digitally recorded for 10 minutes to be scored later for aggressive behaviors. Our analysis reveals an emphasis on assessment behaviors during these contests. Furthermore, our analysis reveals that winners more frequently transitioned from high intensity behaviors to pursuit behaviors; conversely, losers more frequently transitioned from both low and high intensity behaviors to retreat. When viewed in light of game theory modeling, these results support the self-determined persistence and war of attrition models because contest duration is based on loser threshold or retreat behaviors. Future studies should include increased size variation between opponents to examine extremes in behavioral patterns.