Letter to the Editor: Yawning as a Behavioral Adaptation to Heat Stress and Water Scarcity in White-Faced Capuchins (Cebus capucinus) (pages 670–671)

摘要

Recently, Campos and Fedigan (2009) described somenbehavioral adaptations to heat stress and water scarcitynin three distinct groups of white-faced capuchins (Cebusncapucinus) inhabiting the Santa Rosa National Park innCosta Rica. The authors conclude that at least one specificnself-directed behavior (‘‘tongue out’’) has a thermoregulatorynfunction. Evidence for this comes from datanshowing that on average, capuchins exposed theirntongues more frequently during hot and dry conditions.nIn particular, tongue out behavior occurred at mean temperaturesnexceeding the 99% bootstrap confidence intervaln(BCI) for temperature and below the 99% BCI for humidity.nAlthough yawning met the same criteria (occurringnduring higher mean temperatures and lower meannhumidity), the authors do not suggest a thermoregulatorynfunction for this behavior. Campos and Fedigann(2009) state, instead, that the observed pattern is ‘‘likelyna byproduct of the association between yawning andnresting,’’ and when considering resting and temperaturenare positively correlated, it was concluded that yawningndoes not participate in thermoregulation. I feel thenauthors are 1) overly vague when referring to yawningnas a byproduct of resting and 2) too quick to discount anthermoregulatory value. Methodological constraints innthis study do not allow for a more convincing examinationnof the po