Behavioral event occurrence differs between behavioral states in Sotalia guianensis (Cetarctiodactyla: Delphinidae) dolphins: a multivariate approach

Maria Alice S. Alves,Rodrigo H. Tardin,Sheila M. Simão,Míriam P. Pinto

doi:10.1590/s1984-46702014000100001

Abstract

Difficulties in quantifying behavioral events can cause loss of information about cetacean behavior, especially behaviors whose functions are still debated. The lack of knowledge is greater for South American species such as Sotalia guianensis (Van Beneden, 1864). Our objective was to contextualize the behavioral events inside behavioral states using a Permutational Multivariate Analysis of Variance (MANOVA). Three events occurred in the Feeding, Socio-Sexual and Travelling states (Porpoising, Side flop, Tail out dive), and five events occurred in the Feeding and Travelling states (Back flop, Horizontal jump, Lobtail, Spy-hop, Partial flop ahead). Three events (Belly exposure, Club, and Heading) occurred exclusively in the Socio-sexual state. Partial Back flop and Head flop occurred exclusively in the Feeding state. For the events that occurred in multiple states, we observed that some events occurred more frequently in one of the states (p < 0.001), such as Lobtail, Tail out dive horizontal Jump, Partial flop ahead and Side flop. Our multivariate analysis, which separated Socio-sexual behavior from Feeding and Travelling, showed that the abundance of behavioral events differs between states. This differentiation indicates that some events are associated with specific behavioral states. Almost 40% of the events observed were exclusively performed in one state, which indicates a high specialization for some events. Proper discrimination and contextualization of behavioral events may be efficient tools to better understand dolphin behaviors. Similar studies in other habitats and with other species, will help build a broader scenario to aid our understanding of the functions of dolphin behavioral events.

Highlights

ALTMANN (1974) described two classes of behaviors: long duration behaviors in which the most common measure is the duration of this behavior and behavioral events, short duration behaviors in which the most common measure is the occurrence of each event
Behavioral event occurrence differs between behavioral states in Sotalia guianensis dolphins
The abundance of behavioral events is clearly different between states, as revealed by our multivariate analysis results, which separated mainly Socio-sexual behavior from Feeding and Traveling

Summary

Introduction

One of the major problems of cetacean behavioral studies is the clustering of different behaviors into only one category, such as jumps (LUSSEAU 2006, AZEVEDO et al 2009). ALTMANN (1974) described two classes of behaviors: long duration behaviors in which the most common measure is the duration of this behavior and behavioral events, short duration behaviors in which the most common measure is the occurrence of each event. ALTMANN (1974) described two classes of behaviors: long duration behaviors in which the most common measure is the duration of this behavior and behavioral events, short duration behaviors in which the most common measure is the occurrence of each event Under this classification, several events may occur inside a single behavioral state. The investigation of which behavioral events occur in the different behavioral states will provide new know ledge in this area. This contextualization is better understood for some cetacean species such as the bottlenose dolphin, Tursiops truncatus (Montagu, 1821) (ACEVEDO-GUTIERREZ 1999, LUSSEAU 2006, MILLER et al 2010). 2014 Sociedade Brasileira de Zoologia | www.sbzoologia.org.br | www.scielo.br/zool All content of the journal, except where identified, is licensed under a Creative Commons attribution-type BY-NC

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