Elliots Storm-petrel (Oceanites gracilis)

Elliots Storm-petrel

Subspecies

Monotypic species

Genus

Storm-petrels are rather small and often dark colored tubenoses with a world wide distribution. All have fine black bills with very pronounced tubes. Storm Petrels are separated in two groups: the long legged, Southern Hemisphere birds subfamily Oceanitinae and the shorter legged species of more northern seas the subfamily Hydrobatinae. The first groups shows more morphological differences than the second. The genera are characterised on colour patterns, the condition of the nasal tubes, tail shape, structure of claws and proportions of the leg bones. The genus Oceanites have their plumage black with white upper- and under-tail coverts and sometimes white on the abdomen; bil short, nasal tubes long (about half length of culme); tarsus booted (scales fused to a continuous sheath) or with obscure scutes; claws little flattened, webs yellow.

Physical charateristics

It is predominately brown to dark grey in colour, tending to be darker on its upperparts and paler on its throat and chest. The square-ended tail is black, except for a white bar that merges with a white-tipped rump to form a conspicuous white crescent. It has brown eyes, a black bill and black feet, which extend well beyond the tail in flight.

wingspan min.:	36	cm	wingspan max.:	40	cm
size min.:	15	cm	size max.:	16	cm
incubation min.:	0	days	incubation max.:	0	days
fledging min.:	0	days	fledging max.:	0	days
broods:	1		eggs min.:	1
			eggs max.:	1

Range

Pacific Ocean : East. Occurs along the cold water Humboldt Current off the west coast of South America

Habitat

White-vented storm-petrels rarely venture more than 100 kilometers from the shore and are most abundant in cool, upwelled waters. usually Storm-petrels are highly pelagic.

Reproduction

In spite of the frequent sightings of this species it is very poorly known; only one nest has ever been found.

Feeding habits

This Storm-petrel flutters over the sea surface, appearing to ?walk-on-water?, in search of plankton and scraps of fish killed by larger predators. This unusual technique is thought to be the origin of the name petrel, derived from the biblical account of St Peter walking on water.

Video Elliots Storm-petrel

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

Conservation

Data deficient
Oceanites gracilis occupies tropical waters of the eastern Pacific Ocean, where it is numerous. Prior to 2003, only one nest had ever been found, on Isla Chungungo, Chile (where rats and fire may have caused a decline). During surveys of the island on 6-11 January 2002 three crevices containing perhaps 11 nests were located in the north-east part of the island. Suitable sites are limited on the island, and alternative sites may be too disturbed by nesting Humboldt Penguins Spheniscus humboldti1. No evidence of rodents or marsupials was found, although the presence of the Short-tailed Snake Tachymenis chilensis may be cause for concern1. A breeding population (subspecies galapagoensis) of several thousands is suspected for the Galapagos, Ecuador.

Elliots Storm-petrel status Data Deficient

Migration

Little known, but apparently relatively sedentary. Some dispersal N in zone of Humboldt Current, and thence perhaps to C Pacific; absent from sea around breeding grounds, Mar-Jun.

Distribution map

Elliots Storm-petrel distribution range map

Planet of Birds