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

Social Recognition

How groups of whales recognize each other and make social and movement decisions on a biological relevant scale remains completely unknown.  I am currently undertaking an unprecedented study which seeks to understand how the sperm whale, a nomadic marine apex predator, mediates its social interactions. In collaboration with Peter Madsen of the Marine Bioacoustics Lab at Aarhus University, we are using innovative animal-borne tags deployed to conduct a controlled playback study with a paired design (familiar call vs unfamiliar call) to test hypotheses of both individual and cultural group recognition. It is this kind of analytical framework that has driven the study of birdsong into one of the most productive areas of behavioural ecology. 

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 23 collaborators at 16 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 Dtags deployed on well-known individuals, we can for the first time address these questions.

Coda 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.

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.

Ontogeny of Calf Behaviour

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 diving, foraging, echolocation, and communication skills. Our ability to access and recognize yearling and juvenile sperm whales enables us to ask questions relating to behavioural development for the first time in this species. Using sound and movement animal-borne tags deployed on calves, we test questions relating to the tradeoff between the development of locomotor skills and social and communicative abilities. This area of inquest allows us also to address hypotheses relating to social learning of coda dialects, diving physiology of deep-diving calves, and maternal investment.

Sperm Whale Body Condition

In collaboration with Fredrik Christiansen from Murdoch University's Cetacean Research Unit, we are assessing the body condition of the Caribbean sperm whale community using drone photogrammetry. This study will also allow the comparison of acoustic and drone based measurements of body size and to assess the short-term behaivoural response of whales to whalewatching and swim-with

Spatial Ecology

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.

International Collaborative Projects

Spatial and Acoustic Ecology of Marine Megafauna

The Spatial and Acoustic Ecology of Marine Megafauna (SPAM) project assembles an international team of research scientists, data analysis specialists/modelers, software developers, citizen science experts, and educational professionals uniquely qualified to explore understudied and cryptic outer continental shelf (OCS) marine megafauna species. That exploration will include the use of passive acoustic monitoring, biotelemetry, visual surveys, software development, citizen science data collection platforms, and education and outreach. The bulk of the field research will be undertaken by teams at University of North Carolina Wilmington (lead by Ann Pabst) and Duke University (lead by Doug Nowacek); while I will be lead on the citizen science component of the project. Promoting citizen science and education are priorities for this initiative, and as such, the work represents the creation of new, pertinent information and its dissemination across local to global audiences. The project will assist government in its mission to protect the health and stability of marine mammals and their ecosystem, while managing OCS resources. This project is funded through a cooperative agreement with the Bureau of Ocean Energy and Management of the US Department of Interior. 

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.