Hostname: page-component-78c5997874-dh8gc Total loading time: 0 Render date: 2024-11-10T11:23:17.488Z Has data issue: false hasContentIssue false

Potential hybridism between free-ranging Risso's dolphins (Grampus griseus) and bottlenose dolphins (Tursiops truncatus) off north-east Lewis (Hebrides, UK)

Published online by Cambridge University Press:  29 August 2014

Nicola K. Hodgins*
Affiliation:
Whale and Dolphin Conservation, 38 St Paul Street, Chippenham, Wiltshire SN15 1LJ, UK
Sarah J. Dolman
Affiliation:
Whale and Dolphin Conservation, 38 St Paul Street, Chippenham, Wiltshire SN15 1LJ, UK
Caroline R. Weir
Affiliation:
Ketos Ecology, 4 Compton Road, Kingsbridge, Devon TQ7 2BP, UK School of Biological Sciences (Zoology), University of Aberdeen, Tillydrone Avenue, Aberdeen, AB24 2TZ, UK
*
Correspondence should be addressed to: Nicola K. Hodgins, WDC, 38 St Paul Street, Chippenham, Wiltshire, SN15 1LJ, UK email: nicola.hodgins@whales.org
Get access

Abstract

Hybrid cetaceans have been documented to occur both in the wild and in captivity. Identifying wild hybrid individuals can be problematic in the absence of genetic techniques, but published accounts indicate that intermediate morphological characteristics are often present. Between 2010 and 2013, a land-based and boat-based study of the Risso's dolphin (Grampus griseus) was carried out in nearshore waters around the Eye Peninsula located on north-east Lewis, Scotland. Three atypical individuals were photographed which exhibited morphological features intermediate between Grampus and the common bottlenose dolphin (Tursiops truncatus). These individuals were typically larger in body size than Tursiops, and had a dorsal fin shape and size consistent with Grampus. Two individuals had coloration most similar to Tursiops and the third exhibited extensive white linear scarring consistent with Grampus. The intermediate morphology was most apparent in the head shape, with all three individuals exhibiting a defined (in contrast to Grampus) but very short (compared with Tursiops) rostrum and two having an unusually steep (compared with Tursiops) forehead. On one occasion, one of the atypical individuals was observed within a mixed-species school of Grampus and Tursiops. There were four further sightings of atypical dolphins associated with Tursiops-only schools. Atypical dolphins were not recorded within Grampus-only schools. These observations are consistent with hybridization between free-ranging Risso's and bottlenose dolphins, the first such occurrence to be documented for these species in UK waters. The context and significance of these hybridization events are unknown.

Type
Research Article
Copyright
Copyright © Marine Biological Association of the United Kingdom 2014 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Amaral, A.R., Lovewell, G., Amato, G. and Rosenbaum, H. (2013) Hybrid speciation in a marine mammal: the clymene dolphin (Stenella clymene). PLoS ONE 9, e83645. doi:10.1371/journal.pone.0083645.Google Scholar
Atkinson, T., Gill, A. and Evans, P.G.H. (1998) A photo-identification study of Risso's dolphins in the Outer Hebrides, north-west Scotland. European Research on Cetaceans 12, 102.Google Scholar
Ballance, L.T. and Pitman, R.L. (1998) Cetaceans of the western tropical Indian Ocean: distribution, relative abundance, and comparisons with cetacean communities of two other tropical ecosystems. Marine Mammal Science 14, 429459.Google Scholar
Bearzi, G. (2000) First report of a common dolphin (Delphinus delphis) death following penetration of a biopsy dart. Journal of Cetacean Research and Management 2, 217221.Google Scholar
Bearzi, M. (2005) Habitat partitioning by three species of dolphins in Santa Monica Bay, California. Bulletin of the Southern Californian Academy of Sciences 104, 113124.Google Scholar
Bérubé, M. and Aguilar, A. (1997) A new hybrid between a blue whale, Balaenoptera musculus, and a fin whale, B. physalus: frequency and implications of hybridization. Marine Mammal Science 14, 8298.CrossRefGoogle Scholar
Bérubé, M. (2009) Hybridism. In Perrin, W.F., Würsig, B. and Thewissen, J.G.M. (eds) Encyclopedia of marine mammals. 2nd edition. New York: Academic Press, pp. 588591.CrossRefGoogle Scholar
Cetabase (2013) Available at: http://www.ceta-base.com/phinventory/phins_beachland.html (accessed 30 January 2014).Google Scholar
Dolman, S.J. and Hodgins, N.K. (2013) Land and boat-based observations of Risso's dolphins off NE Isle of Lewis, Scotland. In Chen, I., Hartman, K., Simmonds, M., Wittich, A. and Wright, A.J. (eds) Grampus griseus 200th anniversary: Risso's dolphins in the contemporary world. Report from the European Cetacean Society Conference Workshop, 26th European Cetacean Society Conference, Galway, Ireland, 23–29 March 2012. European Cetacean Society Special Publication Series No. 54, pp 44–53.Google Scholar
Evans, P.G.H., Lewis, E.J., Parsons, E. and Swann, C. (1993) A survey of whales and dolphins in Hebridean waters. Oxford: SeaWatch Foundation, 11 pp.Google Scholar
Fraser, F.C. (1940) Three anomalous dolphins from Blacksod Bay, Ireland. Proceedings of the Royal Irish Academy; Section B: Biological, Geological and Chemical Science 45 (1938–1940), 413–455.Google Scholar
Herzing, D.L. and Johnson, C.M. (1997) Interspecific interactions between Atlantic spotted dolphins (Stenella frontalis) and bottlenose dolphins (Tursiops truncatus) in the Bahamas, 1985–1995. Aquatic Mammals 23.2, 8599.Google Scholar
Herzing, D.L., Moewe, K. and Brunnick, B.J. (2003) Interspecies interactions between Atlantic spotted dolphins, (Stenella frontalis) and bottlenose dolphins, (Tursiops truncatus), on Great Bahama Bank, Bahamas. Aquatic Mammals 29.3, 335341.Google Scholar
HWDT (2014) Hebridean Whale and Dolphin Trust unpublished data and distribution maps. Available at: http://www.whaledolphintrust.co.uk (accessed 27 January 2014).Google Scholar
Jefferson, T.A., Weir, C.R., Anderson, R.C., Ballance, L.T., Kenney, R.D. and Kiszka, J.J. (2014) Global distribution of Risso's dolphin Grampus griseus: a review and critical evaluation. Mammal Review 44, 5668.CrossRefGoogle Scholar
Karczmarski, L., Thornton, M. and Cockcroft, V.G. (1997) Description of selected behaviours of humpback dolphins, Sousa chinensis . Aquatic Mammals 23.3, 127133.Google Scholar
Macleod, C.D., Santos, M.B., Burns, F., Brownlow, A. and Pierce, G.J. (2013) Can habitat modelling for the octopus Eledone cirrhosa help identify key areas for Risso's dolphin in Scottish waters? Hydrobiologia. doi: 10.1007/s10750-013-1555-0.Google Scholar
Maze-Foley, K. and Mullin, K.D. (2006) Cetaceans of the oceanic northern Gulf of Mexico: Distributions, group sizes and interspecific associations. Journal of Cetacean Research and Management 8, 203213.CrossRefGoogle Scholar
Melillo, K., Dudzinski, K. and Cornick, L. (2009) Interactions between Atlantic spotted (Stenella frontalis) and bottlenose (Tursiops truncatus) dolphins off Bimini, The Bahamas, 2003–2007. Aquatic Mammals 35, 281291.CrossRefGoogle Scholar
Pierpoint, C., Baines, M. and Earl, S. (1998) The harbour porpoise (Phocoena phocoena) in West Wales. A briefing report to The Wildlife Trusts and The Worldwide Fund for Nature, 34 pp.Google Scholar
Reid, J.B., Evans, P.G.H. and Northridge, S.P. (2003) Atlas of cetacean distribution in north-west European waters. Peterborough: Joint Nature Conservation Committee, 76 pp.Google Scholar
Reyes, J. (1996) A possible case of hybridism in wild dolphins. Marine Mammal Science 12, 301307.Google Scholar
Santos, M.B., Pierce, G.J., Reid, R.J., Patterson, I.A.P., Ross, H.M. and Mente, E. (2001) Stomach contents of bottlenose dolphins (Tursiops truncatus) in Scottish waters. Journal of the Marine Biological Association the United Kingdom 81, 873878.Google Scholar
Shimura, E., Numachi, K., Sezaki, K., Hirosaki, Y., Watabe, S. and Hashimoto, K. (1986) Biochemical evidence of hybrid formation between the two species of dolphin Tursiops truncatus and Grampus griseus . Bulletin of the Japanese Society of Scientific Fisheries 52, 725730.CrossRefGoogle Scholar
Spilliaert, R., Vikingsson, G., Arnason, U., Palsdottir, A., Sigurjonsson, J. and Arnason, A. (1991) Species hybridization between a female blue whale (Balaenoptera musculus) and a male fin whale (B. physalus): molecular and morphological documentation. Journal of Heredity 82, 269274.CrossRefGoogle Scholar
Stensland, E., Angerbjorn, A. and Berggren, P. (2003) Mixed species groups in mammals. Mammal Review 33, 205223.Google Scholar
Sylvestre, J.P. and Tasaka, S. (1985) On the intergeneric hybrids in cetaceans. Aquatic Mammals 11.3, 101108.Google Scholar
Weir, C.R., Pollock, C., Cronin, C. and Taylor, S. (2001) Cetaceans of the Atlantic Frontier, north and west of Scotland. Continental Shelf Research 21, 10471071.Google Scholar
Weir, C.R. (2011) Distribution and seasonality of cetaceans in tropical waters between Angola and the Gulf of Guinea. African Journal of Marine Science 33, 115.Google Scholar
Würsig, B. and Jefferson, T.A. (1990) Methods of photo-identification for small cetaceans. In Hammond, P.S., Mizroch, S.A. and Donovan, G.P. (eds) Individual recognition of cetaceans: use of photo-identification and other techniques to estimate population parameters. Reports of the International Whaling Commission Special Issue 12, 43–52.Google Scholar
Zornetzer, H.R. and Duffield, D.A. (2003) Captive-born bottlenose dolphin × common dolphin (Tursiops truncatus × Delphinus capensis) intergeneric hybrids. Canadian Journal of Zoology 81, 17551762.CrossRefGoogle Scholar