Tagging picture courtesy of Jeniffer Modigliani

Social Structure

Three levels of sperm whale social structure (individual, unit, and clan) as defined by both social and communication networks

Three levels of sperm whale social structure (individual, unit, and clan) as defined by both social and communication networks

Network Approach

I am particularly interested in animal social networks, how and why they form, and more recently, by necessity, what happens when they fall apart. 

Most recently, I have been using interaction networks to study how connectivity structures sperm whale society.


Communication

'Sam' from Unit S carrying a Dtag3

'Sam' from Unit S carrying a Dtag3

Context, Syntax and Vocal Leadership

If coda types have differing functions, one would expect to find differing patterns to their usage across behavioural and social contexts, in their ordering during vocal exchanges and based on the identity of the the signaler and receiver. Using multiple animal-borne Dtags deployed on well-known individuals, we can for the first time address these questions.

In collaboration with Peter Madsen, Aarhus University


Coda Classification

5-click coda types from the Caribbean classified to type by OPTICS

5-click coda types from the Caribbean classified to type by OPTICS

If calls have differing functions, you would expect their patterns of variation to differ as they would face differing selective forces. In order to address this, we must first have an understanding of different call types.

As a part of my current fellowship, I am developing new methods to classify sperm whale calls using density-based clustering algorithms and compare the similarity of types using various algorithms, including Dynamic Time Warping borrowed from speech recognition, in order to examine hierarchical classification of calls, and potentially the evolutionary pathway of different types.

In collaboration with Hal Whitehead and Mauricio Cantor of Dalhousie University and Luke Rendell of the University of St. Andrews


Locations of sites where coda repertoires have been studied.

Locations of sites where coda repertoires have been studied.

Global Patterns of Dialect Variation

I am currently leading a multi-institutional team of researchers to summarize global diversity of socially-leaned vocal repertoires in sperm whales. This is an ambitious long-term project.


Movement

Home Ranging

Sperm whales are nomadic, but appear to have large ephemeral homeranges; however, they have never been defined nor examined as a community of overlapping family homeranges. With the existing understanding of the social network and using satellite telemetry, I hope to outline a biologically relevant scale of social contacts in this species.