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The little penguin (Eudyptula minor), also known as the blue penguin or fairy penguin, inhabits the coasts and offshore islands of New Zealand and southern Australia. As its names suggests, it is the smallest of the living penguins at just 25 cm tall and 1 kg in weight (although one fossil species was probably a few centimeters shorter), and is mostly blue in color. They eat mainly fish (sometimes supplemented with squid and crustaceans), can undertake long foraging trips of up to 750 km, and can live to be 25 years old (Davis and Renner, 2003).
Penguins in general (see also Spheniscus demersus, the jackass penguin, Aptenodytes forsteri, the emperor penguin, and Pygoscelis adeliae, the Adelie Penguin) are highly derived avians with no clear relatives among other living birds, although most studies suggest that they are related to one among a number of seabirds. These possible sister groups include loons (Olson 1985), loons and grebes (Sibley and Ahlquist, 1990; Mayr and Clarke, 2003), and tubenoses (albatrosses and petrels; Simpson, 1946; Livezey and Zuzi, 2001; Bertelli and Giannini, 2005). This confusion is probably due to convergence among seabirds adapted to similar environments and to the fact that penguins evolved nearly 55 million years ago and have since undergone extreme morphological and genetic modification (Fordyce and Jones, 1990).
Relationships within penguins are also controversial and largely unresolved, although the six living genera almost certainly form natural groups. Little penguins may be most closely related to Spheniscus penguins (the Galapagos, Jackass, Humboldt, and Magellanic penguins) (O’Hara, 1989; Bertelli and Giannini, 2005) or to Spheniscus and crested penguins together (Paterson, 1995; Triche, unpubl. data). Little penguins share skeletal characters such as a humerus with an only partially divided tricipital fossa, a shortened dentary bone, and a completely fused naso-premaxillary suture (Bertelli and Giannini, 2005; Triche, unpbul. data).
Eudyptula minor has been divided into six subspecies, one of which is shown here. This subspecies, the white-flippered penguin (Eudyptula minor albosignata), is restricted to the Banks Peninsula and Motunau Island of New Zealand (on the East coast of the South Island). It can be differentiated from the other subspecies by its white flippers and slightly larger size (Kinsky and Fall, 1976). Little penguins are extremely odd, breeding in underground burrows and coming ashore only at night, probably to avoid added predation pressure. There is currently no hypothesis of the relationships of little penguin subspecies.
Penguins are entirely aquatic and have evolved numerous associated adaptations, including specialized salt glands (which allow them to drink salt water), extremely flattened wing bones, and a unique system of water-proof feathers (Davis and Renner, 2003). Although penguins probably originated in very southerly latitudes and then adapted to extreme cold weather (Triche, unpubl. data), little penguins all inhabit slightly warmer climates. They live from about 30-50°S, but most of their habitat is either temperate beaches or forests. Their nocturnal habits are one way of adapting to this warmer climate.
Little penguins, although not listed as threatened or endangered, are in decline due to extreme predation by introduced mustelids (ferrets, stoats, and weasels) and dogs, as are many flightless New Zealand birds. The New Zealand Department of Conservation has listed the little penguin as “near threatened” and implemented predator control programs.
Additional Information on the Skull
Click on the thumbnails below for labeled images of the skull in standard anatomical views.
About the Species
This specimen (UF 31924) was made available to The University of Texas High-Resolution X-ray CT Facility for scanning by Dr. Nina Triche of the UT Department of Geological Sciences. Funding for scanning was provided by a UT Geology Foundation grant to Dr. Triche. Funding for image processing was provided by a National Science Foundation Digital Libraries Initiative grant to Dr. Timothy Rowe of The University of Texas at Austin.
About this Specimen
This specimen was scanned by Matthew Colbert on 14 September 2005 along the coronal axis for a total of 810 slices. Each slice is 0.113 mm thick, with an interslice spacing of 0.113 mm and a field of reconstruction of 50 mm.
About the
Scan
Literature
Bertelli, S., and N.P. Giannini. 2005. A phylogeny of extant penguins (Aves: Sphenisciformes) combining morphology and mitochondrial sequences. Cladistics 21:209-239.
Davis, L. S., and M. Renner. 2003. Penguins. Yale University Press, New Haven. 212 pages.
Fordyce, R. E., and C. M. Jones. 1990. Penguin history and new fossil material from New Zealand. Pp. 419-446 in: L. S. Davis, and J. T. Darby (eds), Penguin Biology. Academic Press.
Giannini, N. P., and S. Bertelli. 2004. Phylogeny of extant penguins based on integumentary and breeding characters. The Auk 121:422-434.
Kinsky, F. C., and R. A. Falla. 1976. A subspecific revision of the Australasian blue penguin (Eudyptula minor) in the New Zealand area. National Museum of New Zealand Records 167 or 1:105-126.
Livezey, B, B., and R. L. Zuzi. 2001. Higher-order phylogenetics of modern Aves based on comparative anatomy. Netherlands Journal of Zoology 51:179-205.
Mayr, G., and J. Clarke. 2003. The deep divergences of neornithine birds: a phylogenetic analysis of morphological characters. Cladistics 19:527-553.
O’Hara, R. J. 1989. Systematics and the study of natural history, with an estimate of the phylogeny of the living penguins (Aves: Spheniscidae). Ph.D., Harvard University. 171 pg.
Olson, S. L. 1985. The fossil record of birds. Pp. 79-239 in: D. Farner, J. King, and K. Parkes (eds) Avian Biology vol 8. Academic Press.
Paterson, A. M., G. P. Wallis, and R. D. Gray. 1995. Penguins, petrels, and parsimony: does cladistic analysis of behavior reflect seabird phylogeny? Evolution 49:974-989.
Sibley, C. G., and J. E. Ahlquist. 1990. Phylogeny and classification of birds: a study in molecular evolution. Yale University Press, New Haven.
Simpson, G. G. 1946. Fossil penguins. Bulletin of the American Museum of Natural History 87:1-99.
Williams, T. D. 1995. The Penguins. Oxford University Press, Oxford.
Links
Eudyptula minor page from the International Penguin Conservation Work Group
E. minor page on the New Zealand Penguins website
E. minor species account on The Animal Diversity Web (The University of Michigan Museum of Zoology)
E. minor albosignata page on the New Zealand Penguins website
Literature
& Links
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