Research Methods

Our research program integrates non-invasive techniques including: photo-identification to determine who is who with pictures of the animalsí tails; genetic techniques using shed skin allows us to determine who is related to whom; a passive acoustic recording program allowing us to study the sounds the sperm whales make; as well as fecal sampling to examine diet. The whales have been studied from a research sailing vessel, a small dedicated outboard skiff, and in partnership with a whalewatch operator in the waters off the leeward side of the island of Dominica, West Indies.

Research during the 2014 and 2015 research seasons is being completed in collaboration with Dr. Peter Madsen who leads the Marine Bioacoustics Lab at Aarhus University. Objectives are focused on understanding the context and function of sperm whale social calls though the use of animal-borne sound and movement tags. Dr. Madsen's is a world-leading bioacoustian and has helped pioneer the Dtag technology. Learn more about Dtags here:

Research carried out off the coast of Dominica is conducted under research permits granted by the Fisheries Division of the Ministry of Environment, Natural Resources, Physical Planning and Fisheries of the Government of Dominica.


2015 |2014 |2013 |2012 |2011 | 2010 | 2009 | 2008 | 2007


S. Gero, J. Gordon, and H. Whitehead (In Press) Individualized social preferences and long-term social fidelity between social units of sperm whales. Animal Behaviour.

H. Whitehead and S. Gero (In Press) Positive observed rates of increase do not reflect a healthy population: conflicting rates of increase in the sperm whale population of the eastern Caribbean. Endangered Species Research. PDF


S. Gero, M. Milligan, C. Rinaldi, P. Francis, J. Gordon, C. Carlson, A. Steffen, P. Tyack, P. Evans, and Hal Whitehead (2014) Behavior and Social Structure of the Sperm Whales of Dominica, West Indies. Marine Mammal Science PDF

H. Whitehead and S. Gero (2014) Using social structure to improve mortality estimates; an example with sperm whales. Methods in Ecology and Evolution PDF


S. Gero, J. Gordon, and H. Whitehead. (2013). Calves as social hubs: dynamics of the social network within sperm whale units. Proceedings of the Royal Society B. DOI: 10.1098/rspb.2013.1113 PDF


S. Gero (2012) The surprisingly familiar family lives of sperm whales. Journal of the America Cetacean Society 41: 16-20.

H. Whitehead, R. Antunes, S. Gero, D. Engelhaupt, and L. Rendell (2012) Multilevel societies of female sperm whales (Physeter macrocephalus) in the Atlantic and Pacific: why are they so different? International Journal of Primatology 33: 1142-1164. DOI: 10.1007/s10764-012-9598-z PDF


R. Antunes, T. Schulz, S. Gero, H. Whitehead, J. Gordon and L. Rendell (2011) Individually distinctive acoustic features in sperm whale codas Animal Behaviour 81(4): 723-730. DOI:10.1016/j.anbehav.2010.12.019 PDF


T.M. Schulz, H. Whitehead, S. Gero and L. Rendell (2010) Individual vocal production in a sperm whale (Physeter macrocephalus) social unit. Marine Mammal Science 27(1): 149-166. DOI:10.1111/j.1748-7692.2010.00399.x PDF


D. Engelhaupt, A.R. Hoelzel, C. Nicholson, A. Frantzis, S. Mesnick, S. Gero, H. Whitehead, L. Rendell, P. Miller, R. De Stefanis, A.A. Mignucci-Giannoni (2009) Female philopatry in coastal basins and male dispersion across the North Atlantic in a highly mobile marine species, the Sperm whale (Physeter macrocephalus). Molecular Ecology 18: 4193-4205. DOI:10.1111/j.1365-294x.2009.04355.x PDF

S. Gero, D. Engelhaupt, L. Rendell, and H. Whitehead (2009) Who Cares? Between-group variation in alloparental care-giving in sperm whales. Behavioral Ecology 20(4): 838-843. DOI:10.1093/beheco/arp068 PDF


T.M. Schulz, H. Whitehead, S. Gero, and L. Rendell (2008) Overlapping and matching of codas in vocal interactions between sperm whales: Insights into communication function. Animal Behaviour 76: 1977-1988. DOI: 10.1016/j.anbehav.2008.07.032 PDF

S. Gero, D. Engelhaupt, and H. Whitehead (2008) Heterogeneous associations within a sperm whale unit reflect pairwise relatedness. Behavioural Ecology and Sociobiology 63: 143-151.
DOI: 10.1007/s00265-008-0645-x
PDF Supplimentary Material

D. Lusseau, H. Whitehead, and S. Gero (2008) Incorporating uncertainty into the study of animal social networks. Animal Behaviour 75(5): 1809-1815. DOI: 10.1016/j.anbehav.2007.10.029 PDF


S. Gero, J. Gordon, C. Carlson, P. Evans, and H. Whitehead (2007) Population estimate and inter-island movement of sperm whales, Physeter macrocephalus, in the Eastern Caribbean. Journal of Cetacean Research and Management 9(2): 143-150. PDF

S. Gero and H. Whitehead (2007) Suckling behaviour in sperm whales calves: observations and hypotheses. Marine Mammal Science 23(2): 398-413. DOI: 10.1111/j.1748-7692.2007.00113.x PDF


S. Gero (2012) On the dynamics of social relationships and vocal communications between individuals and units of sperm whales. Ph.D. Thesis, Department of Biology, Dalhousie University, Halifax, Canada, 163pp.

S. Gero (2011) Sperm Whale IN: Cachalot. The Digital Sea Monsters iPad Application Project, Duke University. Accessed at:

S. Gero, M. Milligan, H. Whitehead (2005-2012) Yearly reports on research activity and management recommendations. Report to the Ministry of Fisheries of Dominica.

S.Gero (2011) Sperm Whale. OCEANA Marine Wildlife Encyclopedia (Online). Accessed at:

S.Gero (2010) Sperm Whale. Society for Marine Mammalogy Species Fact Sheet (Online). Accessed at:

S. Gero (2008) CARIBwhale Cetacean Watching Guidelines: Background and recommendations for their development. pp.22. PDF

T. Schulz (2007) The production and exchange of sperm whale coda vocalizations. Ph.D. thesis, Department of Biology, Dalhousie University, Halifax, Canada, 249pp.

S. Gero, J. Gordon, C. Carlson, P. Evans, and H. Whitehead. (2006) Population estimate and inter-island movement of sperm whales, Physeter macrocephalus, in the Eastern Caribbean. Report to the Scientific Committee at the 58th annual meeting of the International Whaling Commission (SC/58/O4)

S. Gero, and H. Whitehead (2006) Opportunistic sightings of small cetaceans off the leeward shore of the Commonwealth of Dominica. Report to the Small Cetcean Subcommittee at the 58th annual meeting of the International Whaling Commission (SC/58/SM1) PDF

S. Gero (2005) Fundamentals of Sperm Whale Societies: Care for Calves. M.Sc. Thesis, Dalhousie University, Halifax, N.S. 99pp.

L. Rendell, S. Gero, and H. Whitehead (2005) Sperm Whales in Dominica: a case study. Scientific reference paper for the United Nations Environment Programme Regional Workshop of Experts on the Development of the Marine Mammal Action Plan for the Wider Caribbean Region. July 2005. 12pp.