Presented a talk on ruffed lemur contrafreeloading with SMARTA last week at Behaviour 2019. The abstract for the talk can be found on their website. ABSTRACT:
Do Captive Ruffed Lemurs (Varecia spp.) Contrafreeload or Forage Using Optimal Foraging Theory? Raymond Vagell1, Sara Matters2, Andrea L. Baden3,4,5. 1Primate Molecular Ecology Lab (PMEL), New York, New York, United States; 2Training Matters LLC, Brattleboro, Vermont, United States; 3Department of Anthropology, Hunter College of the City University of New York, New York, New York, United States; 4Departments of Anthropology and Biology, The Graduate Center of the City University of New York, New York, New York, United States; 5The New York Consortium in Evolutionary Primatology, New York, New York, United States
Free-ranging animals tend to forage by minimizing energy cost and maximizing energy gain, which could be explained using optimal foraging theory (OFT). Captive animals, however, shouldn’t need to forage using OFT because food is provided to them. The captive population (n=5) of ruffed lemur (Varecia spp.) at Duke Lemur Center are trained to use a touchscreen (SMARTA) for color vision tests. Given a choice between feeding from a bowl or using SMARTA to obtain food, they chose to approach the bowl first (70%) more than SMARTA (30%). However, we found no significant difference in preference for the bowl over SMARTA (X2(1, N = 5) = 6.4, p = 0.0114). Even if lemurs chose to approach the bowl first, they would contrafreeload with SMARTA when food remained in the bowl and consume between 71% to 95% of the SMARTA food. Although these lemurs seem to prefer feeding from a bowl to using SMARTA, we found that they do contrafreeload. We posit that SMARTA is a secondary source of reinforcement, providing enriching cognitive problem solving for these captive Varecia spp. and promoting good welfare.