Cultural transmission of tool use by Indo-Pacific bottlenose dolphins (Tursiops sp.) provides access to a novel foraging niche.
Culturally transmitted tool use has important ecological and evolutionary consequences and has been proposed as a significant driver of human evolution. Such evidence is still scarce in other animals. In cetaceans, tool use has been inferred using indirect evidence in one population of Indo-Pacific bottlenose dolphins (Tursiops sp.), where particular dolphins ('spongers') use marine sponges during foraging. To date, evidence of whether this foraging tactic actually provides access to novel food items is lacking. We used fatty acid (FA) signature analysis to identify dietary differences between spongers and non-spongers, analysing data from 11 spongers and 27 non-spongers from two different study sites. Both univariate and multivariate analyses revealed significant differences in FA profiles between spongers and non-spongers between and within study sites. Moreover, FA profiles differed significantly between spongers and non-spongers foraging within the same deep channel habitat, whereas the profiles of non-spongers from deep channel and shallow habitats at this site could not be distinguished. Our results indicate that sponge use by bottlenose dolphins is linked to significant differences in diet. It appears that cultural transmission of tool use in dolphins, as in humans, allows the exploitation of an otherwise unused niche.
Evolutionary Genetics Group, Anthropological Institute and Museum, University of Zurich, , Winterthurerstrasse 190, Zurich 8057, Switzerland, Institute of Biological and Environmental Sciences, University of Aberdeen, , Aberdeen, UK, Evolution and Ecology Research Centre, School of Biological, Earth, and Environmental Sciences, University of New South Wales, , Sydney, New South Wales 2052, Australia, Marine Scotland Science, Marine Laboratory, , PO Box 101, 375 Victoria Road, Aberdeen AB11 9DB, UK, Murdoch University Cetacean Research Unit, School of Veterinary and Life Sciences, Murdoch University, , Murdoch, Western Australia 6150, Australia, School of Veterinary and Life Sciences, Murdoch University, , Murdoch, Western Australia 6150, Australia.
Michael
M
Krützen
Sina
S
Kreicker
Colin D
CD
MacLeod
Jennifer
J
Learmonth
Anna M
AM
Kopps
Pamela
P
Walsham
Simon J
SJ
Allen
D000273:Adipose Tissue / Q000737:chemistry; D000818:Animals; D001070:Appetitive Behavior; D003469:Culture; D004032:Diet; D004289:Dolphins / Q000502:physiology*; D005227:Fatty Acids / Q000378:metabolism; D005260:Female; D008297:Male; D011161:Porifera; D053001:Tool Use Behavior; D014904:Western Australia
D005227:Fatty Acids
culture; foraging specialization; intra-specific competition; niche exploitation; tool use