Picture of sperm whale calf courtesy of Amanda Cotton

Research Overview

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

Social Structure

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.

Culture

Global Patterns of Dialect Variation

The Global Coda Repertoire Project seeks to describe the geographic extent of sperm whale vocal clans. Sperm whale clans differ in their movement patters, habitat use, foraging success, social behaviour, fitness, and likely across a myriad of behaviours we still do not understand. Clans are recognizable by a membership which appears to identify themselves; and while clans are sympatric in several areas, they remain socially segregated. In collaboration with 56 collaborators at 21 academic institutions and NGOs around the world, we are addressing questions about the ethnogeography of a globally distributed marine mammal across a biologically meaningful scale in an attempt to relate cultural boundaries to ecology and oceanography

Communication

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 tags deployed on well-known individuals, as well as our large dataset of recordings since 2005, I am working with multiple collaborators in Project CETI, from MIT CSAIL, UC Berkeley, and University of Haifa, to address questions about the variability of codas across additional parameters than just rhythm and tempo, the higher level structure of coda exchanges, the long-range syntax of codas within vocal exchanges, how coda exchanges vary across social and behavioural contexts, and about vocal asymmetries in who speaks and when.

We address these questions using novel methods based in signal processing, and now also using modern neural network approaches.

Automated Coda Annotation and Classification

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.

Working with partners in Project CETI at MIT CSAIL and the University of Haifa, we are developing new automated methods to first detect sperm whale clicks in large volumes of audio, classify clicks into echolocation or coda clicks, conduct source separation between synchronously vocalizing whales, annotate coda clicks as belonging to the same coda and finally to classify sperm whale codas into types using both signal processing and machine learning approaches.

Ontogeny of Calf Communication

Deep-diving sperm whales have a complex social structure and the biggest brains on the planet, but very little is known about the ontogeny of their communication skills. Our ability to access and recognize yearling and juvenile sperm whales enables us to ask questions relating to calf directed communication and social learning of codas. We test questions relating to changes in coda production when in the presence of calves and calf vocal production over years. This area of inquest allows us also to address hypotheses relating to social learning of coda dialects, behavioural development, and maternal investment.

Spatial Ecology of Sperm Whale Society

Very little is known about sperm whale spatial ecology. In particular, to what degree can and does the presence and recognition of conspecifics drive movement decisions, habitat use, and abundance and distribution. Using acoustic cues generated by the sperm whales’ echolocation, my collaborators and I are developing a new methods of identifying social units remotely from autonomous acoustic buoys. This approach could allow us to remotely track movements of identified units of whales across scales larger than otherwise possible to operate using traditional methods. With the existing understanding of the social network in this community, I hope to outline a biologically relevant scale of social interactions in this species and test hypotheses about social recognition, culturally transmitted dialects, home ranging, and movement ecology.

Technology

Working with partners in Project CETI at the Harvard’s Microrobotics Lab and REACT Lab, we are developing new technology to record whales in novel ways. From an innovative, open-source, animal-borne sound and movement tag, to automating drone deployment and recovery of tags and algorithms to predict whale movement from live audio recorded on our research vessel; we are advancing our ability study and document the behaviour of sperm whales.

International Collaborative Projects

Project CETI

Project CETI (Cetacean Translation Initiative) is scientist-led, multi-institutional research initiative applying advanced machine learning and gentle robotics to listen to and decipher sperm whale communication. Project CETI is a 2020 TED Audacious Project.

CETI’s science team is made up of world’s leading artificial intelligence and natural language processing experts, cryptographers, linguists, marine biologists, roboticists, and underwater acousticians from a network of universities and other partners.

As a founding partner in Project CETI, Shane’s in-depth knowledge and long-term dataset of the sperm whale community in the Eastern Caribbean has provided the decades of baseline data upon which to launch the initiative in 2020.

Flukebook

Flukebook (http://www.flukebook.org) is the first non-profit web platform that engages both the research and citizen science communities for conservation. It provides researchers with the tools needed for scientific analysis and enables multi-institutional collaborative studies without sacrificing approachability for citizen scientist users. In Flukebook, researchers have access to data management tools, A.I.-trained photo-matching with computer vision algorithms, a global catalog of individuals, and easy connectivity to common analytical software for mark-recapture, genetic, and socio-ecological studies. For citizen scientists, Flukebook enables participants to receive automatic and comprehensive profile updates on individuals they have sighted, transforming “data” into learning and encouraging repeat participation and engagement in conservation initiatives in those regions. I am developing Flukebook with the team of software developers at Wild Me; as well as through their partnerships with biologists and computer scientists as a part of the broader Wildbook project.