Previous studies of Atlantic bottlenose dolphin, Tursiops truncatus, social structure near Sarasota, Florida, revealed two distinct patterns of ranging and association among paired and unpaired adult males. We evaluated these patterns using a longer-term dataset to examine whether they represent alternative strategies. Males were categorized as paired or unpaired based on coefficients of association using survey data collected year-round from 1993 to 2000. Longitudinal data also allowed for determination of lifetime pair-bond status, which enabled analysis of the occurrence of alternative strategies. Male associations with other males and with females of differing reproductive states were examined annually and seasonally. No significant differences were found between paired and unpaired males in either spatial or temporal patterns of association with all classes of females. Lagged association analysis shows that males tend to associate with breeding females preferentially well before the breeding season starts, suggesting that they may develop affiliative relationships with females during the nonbreeding period to influence female choice later. Paired and unpaired males differed in ranging patterns as calculated by the fixed kernel method. Paired males had significantly larger overall ranging areas (95% utilization distribution (UD)) and core areas (25% UD) than unpaired males. Although these differences were significant, additional demographic analyses of lifetime probability of pair-bond formation suggest that pair bonding is the norm among adult males and that unpaired males are a transitional stage rather than an alternative strategy.

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Aerial videogrammetry from an airship tethered to a boat was used to assess the life‐stage structure of manatees in the Blue Waters area of the Homosassa River on the west coast of central Florida. Individual frames of videos were loaded onto a computer and lengths of manatees measured using graphics software. All images of manatees were measured independently by three observers. Measurements were transformed to total manatee lengths by calculating the ratio between the measurements of a reference object of known length and the measurement of the manatee. Length estimates were highly variable but were unbiased with respect to observer. Results of an analysis of variance suggested that the hypothesis that lengths differed among days and among observers should not be rejected. Life‐stage structures were represented in three schemes. One scheme‐which included four life stages: dependent calves, juveniles, animals in tramsition between juvenile and adult, and adults‐was included to provide the most information without sacrificing confidence in the life‐stage distribution. Overall, the video system was effective at capturing images of manatees for life‐stage characterization and, with improvements in image resolution, could become a valuable tool for photo‐identification in sight‐resight experiments.