[MARMAM] new publication on dusky dolphin fission-fusion dynamics

heidipearson at tamu.edu heidipearson at tamu.edu
Sun Jul 12 17:48:05 PDT 2009

The following paper has just been published in Behavioral Ecology and Sociobiology (Online First version):

Pearson, H.C. Influences on dusky dolphin (Lagenorhynchus obscurus) fission-fusion dynamics in Admiralty Bay, New Zealand. 

Abstract: In societies characterized by a high degree of fission-fusion dynamics, individuals adjust their grouping patterns according to the shifting balance of costs and benefits associated with grouping. This study examines influences on fission-fusion dynamics for dusky dolphins (Lagenorhynchus obscurus) in Admiralty Bay, New Zealand. This area is an important foraging habitat for dusky dolphins during the winter and spring. Admiralty Bay has little predation risk, but nearshore mussel farms may infringe on available habitat. I used generalized estimating equations to determine the influences of coordinated foraging, predation risk, and presence of mussel farms on party size, rate of fission-fusion, and behavioral state. I conducted 168 boat-based group focal follows totaling 168 h. The proportion of individuals observed foraging was positively related to party size and rate of party fusion. Resting had no effect on party size and did not vary according to location. Near mussel farms, traveling decreased, and rate of party fission decreased. I conclude that (1) coordinated foraging strategies are a primary influence on fission-fusion dynamics within this population, (2) dolphins may respond to decreased predation risk by not adjusting party size or location during resting, and (3) areas near mussel farms are not used for traveling.

You may download the full article by visiting SpringerLink at http://www.springerlink.com/openurl.asp?genre=article&id=doi:10.1007/s00265-009-0821-7. Alternatively, you may e-mail me at heidipearson at tamu.edu to request a pdf. 

Heidi Pearson, PhD
Assistant Director and Stranding Coordinator
The Whale Center of New England
24 Harbor Loop
P.O. Box 159
Gloucester MA, 01930, USA
ph: 978-515-5001  fax: 978-281-5666

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