How rare is rare? The discovery of the spade-toothed whale

Photo from Current Biology

In 1872, a partially damaged mandible (with teeth) of a beaked whale (Dolichodon layardii) was collected in Pitt Island, Chatham Islands, New Zealand.¹ This specimen was later on determined to be the same species as the specimen identified as Mesoplodon ginkgodens collected in White Island, New Zealand in the 1950’s ² and the specimen identified as Mesoplodon bahamondi collected in Robinson Crusoe Island, Juan Fernández Archipelago, Chile, in 1986¹. Genetic analyses determined that all three specimens belong to the species Mesoplodon traversii². Little is known about the biology of this rare offshore species³, and the fact that there is no evidence of it being consumed as food confirms its rarity in the wild^4. An adult female (17 feet) and a juvenile male (11.5 feet) were sighted on Opape Beach, North Island, New Zealand in December 2010, one of the rare observations made on this species.⁵

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¹van Helden, A.L.; Baker, A.N.; Dalebout, M.L.; Reyes, J.C.; van Waerebeek, K.; Baker, S.C. 2002. Resurrection of Mesoplodon traversii (Gray, 1874), senior synonym of M. bahamodi Reyes (van Waerebeek, Cárdenas and Yánez, 1995) (Cetacea Ziphiidae). Marine Mammal Science 18(3):609-621.
² Baker, A.N.; van Helden, A.L. 1999. New records of beaked whale, Genus Mesoplodon, from New Zealand (Cetacea: Ziphiidae). Journal of the Royal Society of New Zealand 29(3):235–244.
³ France-Presse, A. 2012. Rarest whale spied in New Zealand. Cosmos: The Science of Everything http://www.cosmosmagazine.com/news/6139/rarest-whale-spied-new-zealand [Accessed 12 November 2012].
⁴ Robards, M.D.; Reeves, R.R. 2011. The global extent and character of marine mammal consumption by humans: 1970-2009.
⁵ Stromberg, J. 2012. The world’s rarest whale species spotted in New Zealand. Smithsonian Magazine http://blogs.smithsonianmag.com/science/2012/11/the-worlds-rarest-whale-species-spotted-in-new-zealand/ [Accessed 12 November 2012].


Written by:
Patricia S. Yap
Research Assistant
The SeaLifeBase Project