South Georgia Diving-petrel (Pelecanoides georgicus)

South Georgia Diving-petrel

[order] PROCELLARIIFORMES | [family] Pelecanoididae | [latin] Pelecanoides georgicus | [authority] Murphy and Harper, 1916 | [UK] South Georgia Diving-petrel | [FR] Puffinure de Georgie du Sud | [DE] Breitschnabel-Lummensturmvogel | [ES] Potoyunco de Georgia | [NL] Zuidgeorgische Alkstormvogeltj

Subspecies

Monotypic species

Genus

The genus Pelecanoides is 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. The phylogeny of the Diving Petrels is not much investigated yet. Garnotti diverged from ll 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. 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. 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.

Physical charateristics

Dark bill and eyes, White underparts including underwings. Upperparts dark greyish brown. Wings with white trailing edge. Only bill and nostrils will separate it from other diving petrels.


wingspan min.: 30 cm wingspan max.: 33 cm
size min.: 18 cm size max.: 21 cm
incubation min.: 44 days incubation max.: 52 days
fledging min.: 43 days fledging max.: 60 days
broods: 1   eggs min.: 1  
      eggs max.: 1  

Range

Southern Ocean : widespread. The South Georgia Diving-Petrel has a circumpolar distribution, breeding on South Georgia (Georgias del Sur) in the south Atlantic and on the Prince Edward Islands (South Africa), Crozet and Kerguelen Islands (French Overseas Territories) and Heard Island (Australia) in the southern Indian Ocean. In New Zealand, it breeds on Codfish Island

Habitat

This marine species is found offshore or in cool pelagic waters. It breeds between October and February in colonies on oceanic islands amongst scree or volcanic ash above the tree line, or under sand dunes in areas of relatively flat ground

Reproduction

Around October, a single egg is laid – incubation takes 44-52 days, and fledging takes 43-60 days. About two million pairs breed on South Georgia. It nests in burrows with an end chamber.

Feeding habits

It feeds mainly on planktonic crustaceans, particularly krill, but will also feed on some small fish and young cephalopods. Prey are caught under water in a pursuit-dive or by surface-seizing.

Video South Georgia Diving-petrel

httpv://www.youtube.com/watch?v=bi7523G9PxI

copyright: Gus Yaki


Conservation

This species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
The population is suspected to be in decline owing to predation by invasive species
South Georgia Diving-petrel status Least Concern

Migration

Very little known; presumably sedentary, remaining throughout year in waters adjacent to colony, but movements at sea difficult to detect. Vagrant to SE Australia.

Distribution map

South Georgia Diving-petrel distribution range map

Leave a Reply

Your email address will not be published. Required fields are marked *