Dear colleagues, I am pleased to inform you of my last publication on bottlenose dolphins feeding behaviour. The following paper is now available which considers the likely effects of prey abundance on dolphin's behaviour. Diaz Lopez, B., 2009. The bottlenose dolphin Tursiops truncatus foraging around a fish farm: Effects of prey abundance on dolphins’ behavior. Current Zoology(formerly Acta Zoologica Sinica), 2009, 55(4). Abstract: The extent to which prey abundance influences both bottlenose dolphin foraging behavior and group size in the presence of human activities has not previously been studied. The primary aim of this study was to identify and quantify how wild bottlenose dolphins respond, individually and as groups, to the relative abundance of prey around a fish farm. Detailed views of dolphins’ behavior were obtained by focal following individual animals whilst simultaneously collecting surface and underwater behavioral data. A total of 2150 dive intervals were analyzed, corresponding to 342 focal samples, lasting over 34 hours. Bottlenose dolphins remained submerged for a mean duration of 46.4 seconds and a maximum of 249 seconds. This study provides the first quantified data on bottlenose dolphin diving behavior in a marine fin-fish farm area. This study’s results indicate that within a fish farm area used intensively by bottlenose dolphins for feeding, dolphins did not modify dive duration. Additionally, underwater observations confirmed that dolphins find it easier to exploit a concentrated food source and it appears that hunting tactic and not group size plays an important role during feeding activities. Thus, bottlenose dolphins appear capable of modifying their hunting tactics according to the abundance of prey. When top predators display behavioral responses to activities not directed at them, the task of studying all possible effects of human activities can become even more challenging [Current Zoology 55(4):–2009].
Keywords: Bottlenose dolphin, Tursiops truncatus, diving behavior, foraging behavior, prey abundance, human activities, hunting tactics, aquaculture. If you are interested in a reprint, please email Bruno Diaz Lopez at [email protected] It can be also downloaded from the Current zoology website http://www.actazool.org/paperdetail.asp?id=11221 or BDRI's website www.thebdri.com Regards, Bruno Diaz Lopez Chief Researcher / Marine Zoologist Bottlenose Dolphin Research Institute BDRI V.Armando Diaz Nº4 07020 Golfo Aranci (SS) Italy www.thebdri.com [email protected] tel.+ 39 346 081 5414 tel. + 0789 183 1197
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