Dolphin Research Programs
Wild spinner dolphins off Leeward Oahu
Along the Waianae coast of Oahu in early morning hours, spinner dolphins (Stenella longirostris) gather in shallow inshore waters (< 17 fathoms deep, median depth = 11 m) in Makua Bay, Pokai Bay, and Kahe Point after foraging at night in deeper waters (Lammers, 2004). These areas are used by the dolphins for resting, nursing, and social interactions. Dolphins are often observed milling in these areas in groups ranging from two to a hundred or more individuals. Often, large groups contain smaller sub-groups of individuals that vary unequally in sex and age-class (calves versus non-calves). Occasionally, individual dolphins may display surface-active behaviors (e.g., various in-air spins, slapping various body parts on the surface). In general, feeding is absent from bay behaviors.
To date, studies of the Leeward Oahu spinner dolphins have focused on general characteristics of the population for example their resting habitats, travel routes during times of the day, and general activity levels. (Lammers, 2004). Additionally, some work has been performed studying spinner dolphin acoustics (Lammers & Au, 2003; Lammers, Au, & Herzing, 2003; Lammers, Schotten, & Au, 2006). Although one published study examined long-term resights of a few spinner dolphins (Marten & Psarakos, 1999), little attention has been directed toward the underwater social interactions in conjunction with communication between individual spinners within and between groups.
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Under Federal Research Permits, The Dolphin Institute is starting a long-term study of the social associations and underwater behavior and communication of spinner dolphins along the Leeward coast of Oahu. We will concentrate on photo-identification and concurrent behavioral recordings of social interactions of individual spinner dolphins. The gender of individuals will be determined through underwater observation. Sizing of individuals will be accomplished through underwater videogrammetry and related systems. Finally, communication will be investigated by recording vocalizations using passive acoustics (e.g., hydrophones that are part of the underwater video set-up). By recording behavior simultaneously with acoustics and individual body lengths and genders, we will determine the age/class and sex composition of various social groupings of spinners and examine how different vocalizations correspond to different behavioral states and interactions.
Past groundbreaking studies of dolphin sensory perception, cognition and communication
The Dolphin Institute was formed initially in-part to support and enhance the world-renowned dolphin and whale research center at the Kewalo Basin Marine Mammal Laboratory (KBMML), located in Honolulu. KBMML was founded in 1970 by University of Hawaii professor Dr. Louis M. Herman.
For over thirty years, KBMML pioneered scientific studies of the sensory, cognitive, and communicative abilities of its resident dolphins. These studies revealed how dolphins perceive their world through hearing, vision, and echolocation, the depth and breadth of their intellectual potential, and the mechanisms and processes that contribute to their social life and social world.
Between 1970 and 2004, groundbreaking discoveries at KBMML revealed the ability of bottlenosed dolphins to understand semantic and syntactic elements presented within visually-based and acoustically-based artificial languages, their abilities for both vocal and behavioral imitation, their ability to"image" complexly-shaped objects through echolocation, their spontaneous understanding of television displays and scenes, their understanding of human pointing and gaze cues, their excellent short-term memory for arbitrary sounds, visual items, and behaviors, their ability to generalize
concepts of similarity and difference, their awareness of self and others, their ability to recognize melodic sequences of sounds and spontaneously transpose and recognize sounds across octaves, and their understanding of symbolic references to "named" objects displaced in time or space as well as to their own body parts.
For more information on these studies click here.
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