underwater analysis of the behavioral development of free-ranging Atlantic spotted dolphin calves (birth to 4 years of age)

This investigation is the first to focus on the underwater behaviors and development of free-ranging Atlantic spotted dolphin (Stenella frontalis) mothers and calves. Underwater video recordings of 30 mother/calf pairs, during the calves' first three years of life, and 10 additional videos of four-year-old calves, were analyzed. Behavioral event frequencies were compared to the calf's age bracket (i.e. year-one, two, three and four). Results demonstrate an increase in calf independence in year-four shown by a significant reduction in Nursing Act behaviors, significantly more Feeding/Foraging behaviors, and increased behaviors performed in the proximity of individuals other than the mother or alone. No strong evidence was found for increased maternal rejection behaviors near the end of the estimated weaning period. Additionally, results indicate that, for select behaviors, synchronicity may be increasingly expressed over time. Few differences in behavioral frequency and type were observed between calf genders and between mothers of each gender.