During 1995-1998, I conducted acoustic playback experiments on male toads using small breeding pools at the Ross Reserve. I recorded male vocal responses when I broadcast six different types of toad vocalizations. Calls used in playbacks were synthesized on a computer and played back using a tape recorder. The effect of sperm competition intensity and the expected reproductive payoff on optimal ejaculate expenditure is studied in small-mouthed salamanders, Ambystoma texanum. Multi-male breeding aggregations form in this explosively breeding species in early spring, individual males may deposit 60 or more spermatophores at a given aggregation, and males can participate in multiple breeding aggregations.
Females induct ten or more spermatophores at an aggregation prior to depositing eggs.
Sperm reserves are produced prior to over-wintering and are not replenished during the short breeding season. Using staged mating trials in the field, we ask what effects perceived sperm competition risk and relative size difference have on male-male interactions and male mating behavior. Energy regulation patterns in Carolina chickadees. The project is designed to evaluate behavioral ecological aspects of the joint regulation of body mass and food caches in a small passerine bird. Variables of interest are aspects of food availability, social relationships and the relative costs of food storage.