92-5 Sat Jan 2 Gliding treefrog reproduction: Possible functions of diverse male behavior in terrestrial breeding aggregations Güell, BA*; Gomez, EK; Warkentin, KM; Boston University; Boston University; Boston University bguell@bu.edu https://brandonguell.weebly.com/
Gliding treefrogs, Agalychnis spurrelli, on Costa Rica’s Osa Peninsula breed explosively in huge aggregations with highly male-skewed sex ratios and intense male-male scramble competition. We have observed multiple males cluster around females in attempts to dislodge amplexed males or clasp pairs before and during oviposition. In addition, some non-clasping males position their vents directly beside females’ during oviposition and others kick at recently laid eggs, including after pairs leave. Egg-kicking has been hypothesized to be an antagonistic strategy to remove and kill competitors’ offspring. To test this hypothesis, we assessed whether the male behavior of kicking at egg masses dislodges eggs from them by analyzing video recordings of A. spurrelli in the wild. We analyzed 754 kicks by 57 different males at 47 egg masses, across nine reproductive events and two breeding seasons. Kicking never dislodged the affected eggs, regardless of duration or number of kicks. Our findings suggest that this male egg-kicking behavior serves another purpose and requires further investigation. We hypothesize that clasping amplexed pairs, vent-positioning adjacent to pairs, and egg-kicking function as alternative reproductive tactics in which non-amplexed males fertilize eggs by sperm competition or inseminating remaining unfertilized eggs. Our current work combines behavioral data from video recordings with genetic parentage analysis to assess the function and associated reproductive success of these behaviors. If, as it appears, A. spurrelli exhibit multiple reproductive tactics, this work will create new opportunities for research on reproductive variation in explosive-breeding tropical frogs with terrestrial eggs and may have implications for understanding reproductive systems more broadly.