Antipredator behavior in lemurs: evidence of an extinct eagle on Madagascar or something else?

Goodman (1994) related the antipredator response exhibited by two species of lemurs from southwestern Madagascar against extant birds of prey to the predatory efforts of an extinct eagle, inhabiting the same region about 4000 years ago. He argued that today's smaller raptors, hunting young individuals perhaps only occasionally, represent marginal danger to lemurs. Nevertheless, their activity would be sufficient to impose a continuous reinforcement to a strong antipredator response. I question such an interpretation and instead suggest that extant birds ofprey may indeed represent a strong threat to lemurs and that the same might not have been necessarily true for the extinct eagle. In addition, I propose four optional hypotheses, all of which encompass a marginal role for the extinct eagle.