Charlie Hargrave

I am a bio-acoustician focussed on vocal communication and the variation therein, particularly as relates to marine mammals. I hold a bachelor’s degree in Marine Biology from the University of Exeter and an MSc in Marine Mammal Science from the University of St Andrews. My prior research has included study of the vocal systems of the chestnut-crowned babbler, bottlenose dolphin and humpback whale, including such topics as valence, phonemic contrast and geographic variation. Since the completion of my masters degree I have worked as an RA in St Andrews, conducting an analysis of an acoustic deterrent and startle responses in humpback whales, in collaboration with partners at UiT, Tromsø.

Presence and drivers of geographic variation in delphinid vocal signals

PI and Institution:
Vincent Janik, University of St Andrews

PhD aim:
To determine the presence of geographic variation in delphinid vocal signals across all vocal categories (clicks, burst pulses, whistles) in the Northeast Atlantic, as well as examine the drivers of any variation observed. Species in question include the bottlenose dolphin, white-beaked dolphin and Risso’s dolphin.

PhD objectives:

• Describe vocal geographic variation in the species outlined.
• Investigate the effect of repeated encounters, repeated signals (e.g. signature whistles) and sample size when investigating vocal geographic variation in delphinids to establish best practice.
• Identify potential dialect boundaries that could indicate evolutionarily significant units (ESUs) within delphinid populations.
• Explore how environmental factors relate to the occurrence of ESUs and, for bottlenose dolphins, how they relate to genetic variation and social structure.
• Investigate the effects of geographic variation on the performance of acoustic classifiers used by industry and regulators for monitoring delphinids in the wild.