RESPONSES OF JUVENILE AMERICAN ALLIGATORS (ALLIGATOR MISSISSIPPIENSIS) TO CONTACT CALLS

Abstract

Abstract Crocodylians are known for their ability to vocalize throughout their lives in a variety of social and ecological contexts, particularly during their vulnerable juvenile life stage. However, few studies have analyzed juvenile calls in laboratory settings, fewer still have analyzed them across large sample sizes or with respect to sex and body size, and no studies to date have analyzed crocodylian vocalizations with respect to human conditioning in captivity or animal personality profiles. This study tests juvenile American alligators' (Alligator mississippiensis) ability to respond via movement and callback vocalizations to pre-recorded conspecific contact calls across a large sample size (n=36), and tests for relationships between response rates and juvenile body size and sex. Seventeen and sixteen individuals out of a total of thirty-six responded via movement toward the source of pre-recorded vocalizations across the first and second experimental trials, respectively, whereas none responded through movement toward control sounds; 75% of juveniles who vocalized did so only in response to contact calls rather than controls (though the latter difference was not significant given that only four vocalized in Trial 1, and only a single animal vocalized in Trial 2); there was also no significant difference in movement toward recorded vocalizations across size or sex. However, one particularly vocal individual whose upbringing in captivity was known was identified as a possible unique personality profile given its propensity for callback vocalizations in comparison to its fellow study subjects.