The reliability of pigment pattern‐based identification of wild bottlenose dolphins

Abstract

Long‐term studies often rely on natural markings for individual identification across time. The primary method for identification in small cetaceans relies on dorsal fin shape, scars, and other natural markings. However, dorsal fin markings can vary substantially over time and the dorsal fin can become unrecognizable after an encounter with a boat or shark. Although dorsal fins have the advantage in that they always break the water surface when the cetacean breathes, other physical features, such as body scars and pigmentation patterns can supplement. The goal of this study was to explore the use of dorso‐lateral pigment patterns to identify wild bottlenose dolphins. We employed photographic pigment matching tests to determine if pigmentation patterns showed (1) longitudinal consistency and (2) bilateral symmetry using a 30 yr photographic database of bottlenose dolphins (Tursiops aduncus). We compared experienced dolphin researchers and inexperienced undergraduate student subjects in their ability to accurately match images. Both experienced and inexperienced subjects correctly matched dolphin individuals at a rate significantly above chance, even though they only had 10 s to make the match. These results demonstrate that pigment patterns can be used to reliably identify individual wild bottlenose dolphins, and likely other small cetacean species at other sites.

Document Details

Document Type
Pub Defense Publication
Publication Date
Sep 20, 2017
Source ID
10.1111/mms.12440

Entities

People

  • Eric M. Patterson
  • Ewa Krzyszczyk
  • Janet Mann
  • Lena Marie Vetters Bichell

Organizations

  • Georgetown University
  • National Marine Fisheries Service
  • National Science Foundation
  • Office of Naval Research

Tags

Readers

  • Computer Vision.
  • Marine Mammal Biology
  • Surface Coatings Technology.