Picture of sperm whale calf courtesy of Amanda Cotton
Within-population behavioural variation can greatly affect the ecology of a species and evolutionary outcomes by affecting processes including competition, predation, survival, and selection. While genetics and the environment can play critical roles in creating behavioural variation, among highly social mammals much behaivoural variation can be due to social learning and culture. My research seeks to understand the origins of within-population behavioral variation and uses multiple approaches to study how individuality, social structure and cultural processes affect an individual’s behavioral phenotype.
The cetaceans, the whale and dolphins, are an important taxon for asking these questions as they operate over relatively larger spatial and temporal scales than do most other mammalian species; but also have the cognitive abilities and societies which rival their terrestrial counterparts in complexity; while also providing a dramatic contrast in ecology.
My research has primarily been focused on an innovative and integrative long term study of sperm whales. The Dominica Sperm Whale Project has risen to international excellence and integrates collaborators from at five top-tanking academic institutions. The sperm whale (Physeter macrocephalus) is one such nomadic species whose ranging patterns cover thousands of kilometers and which has a particularly interesting multileveled social structure, which may include the largest mammalian cooperative groups outside of humans.
My recent work has focused the link between multilevel societies and functionally diverse communication systems. I study social networks and use animal-borne tags to understand how these social relationships are mediated through communication to coordinate as a group, identify conspecifics and exchange information.
My previous research can be found in my Publications
Below I outline my Work In Progress
Tagging picture courtesy of Jeniffer Modigliani
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.
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
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.
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.
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.