Extinct Seabird Rediscovered In Laboratory

Wednesday, 12 August, 2009 - 13:06

Three University of Canterbury academics have helped rediscover a seabird thought to have been driven to extinction by hungry European sailors in the late 18th century.

Dr Tammy Steeves, Dr Marie Hale and Adjunct Professor Richard Holdaway (Biological Sciences) are part of a team of scientists from across New Zealand and Australia who have used an innovative multidisciplinary approach to resolve the taxonomic status of the "extinct" Tasman booby (Sula tasmani).

It is the first study of its kind to report the rediscovery of an extinct bird using classical palaeontological data combined with ancient and modern DNA data.

"Many rediscoveries of 'extinct' birds are the result of an intensive search in the field, but ours is a little different - we rediscovered our bird in the laboratory," said Dr Steeves.

"What was once considered to be an extinct species, the Tasman booby (Sula tasmani), turns out be a subspecies of a living species, the masked booby (Sula dactylatra fullagari). And now these charismatic seabirds have a new name - Sula dactylatra tasmani."

Masked boobies are large colonial seabirds that breed on oceanic islands throughout the tropics and subtropics. In addition to having longer wings than birds elsewhere, the masked boobies breeding on three remote island groups in the North Tasman Sea have sepia, not yellow, eyes.

The findings have just been published online in the journal Biology Letters.

Dr Steeves, who is the article's lead author, said the researchers approached the task in two stages. First, they compared standard morphometric measurements of fossil material collected from Norfolk Island to modern specimens collected in the North Tasman Sea. In the second stage, the scientists used ancient and modern DNA methods to compare mitochondrial control region sequences from Norfolk Island fossils to those in a global sample of modern birds.

"Despite limited sampling, we found an overlap in skeletal size between fossil and modern boobies in the North Tasman Sea and show that fossil birds have mitochondrial control region sequences that are identical to those found in modern North Tasman Sea birds."

"In addition to reporting the rediscovery of an 'extinct' seabird taxon, our study highlights the need for a multidisciplinary approach when classifying both past and present diversity."

Future research will explore how these long-winged, sepia-eyed birds came to be so different from their short-winged, yellow-eyed counterparts.

http://www.voxy.co.nz/national/extinct-seabird-rediscovered-laboratory/5/20789

See also: Merging ancient and modern DNA: extinct seabird taxon rediscovered in the North Tasman Sea