Diving-petrels
Genus Pelecanoides
A peculiar group of small petrels form the Southern Hemisphere. In appearance and superficially similar tot the Little Auk or Dovekie from the North, but not related. Six species:
- Peruvian Diving Petrel Pelecanoides garnottii
- Magellanic Diving Petrel Pelecanoides magellani
- South Georgia Diving Petrel Pelacanoides georgicus
- Common Diving Petrel Pelecanoides urinatrix: six subspecies
- P. u. urinatrix. Northern New Zealand and SE Australia
- P. u. chathamensis. Souther New Zealand, Chatham Is.
- P. u. dacunhae. Tristan Da Cunha Group
- P. u. berard. Falkland Is.
- P. u. coppingeri. Southern chile
- P. u. exsul. Rest of subantarctic
Evolution
The phylogeny of the Diving Petrels is not much investigated yet. Analysis by Penhallurick & Wink (2004) shows that garnotti diverged from all other tubenoses about 45.8 My ago, later followed by the divergence of urninatrix some 25.5 My ago. From this lineage georgicus and magellanicus diverged about 18.6 My ago.
Distribution
Diving Petrels are confined to the Southern Hemisphere. The Peruvian Diving Petrel is a bird of the South American west coast along the coast of Peru and Northern Chile. The distribution of the Magellanic Diving Petrel is limited around southern Patagonia and South-Gerogian is an endemic to the island it was named after. Only the six subspecies of the Common Diving Petrel can be found around the globe in subantarctic zone.
Behaviour
As the name says, Diving Petrels are very capable divers and fourage on small euphausids and copepods. Although they look very similar to the smallest Alcids, Diving Petrels use the typical tubenose propulsion techniques: combinend use of wings and feet, where Alcids use only wings for propulsion. Diving Petrels can reach depths of 60 m (urinatrix) tot 80 m (garnotti). The flight of Diving Petrels is mainly by fast flapping, whirring wings, reminsicent to the flight of a bumblebee (Onley & Scofield 2007). Like other petrels all Diving Petrels are not very good walkers.
Osteology
Common Diving Petrel Pelecanoides urinatrix. Falkland Is.
Culme: 15.8 mm; total: 51.4 mm. Courtesey of J. Pompert, The Falkland Fisheries Department and W. v. Gestel.