Using calls to estimate the abundance of inshore dolphins: a case study with Pacific humpback dolphins Sousa chinensis

摘要: * 1. Assessing the number of animals in a population is fundamental requirement for effective wildlife management. Determining this information cetaceans can be logistically difficult, and abundance inshore along most world's coastline unknown. * 2. In study we illustrate potential using sound as tool estimating cetaceans, Pacific humpback dolphins Sousa chinensis . * 3. Acoustic recordings were made conjunction with visual observations school size from land-based platform on Stradbroke Island, Australia. * 4. The mean calls recorded per 3-min sample period was regressed against observed schools which more than three periods recorded. relationship estimated = 2·39 × used to estimate fewer four samples Comparing these results known group sizes indicated that estimation technique acceptable. * 5. Recordings could remotely deployed hydrophone units or submerged autonomous provide occurrence delphinids within an area. * 6. Inexperienced personnel deploy retrieve recording units. Analysis would require training recognize types different species, computer-based recognition programs. * 7. We conclude simple techniques phonations estimates relative one species cetacean. acceptable groups nine individuals should developed assess its usefulness studying other species.