Fluttering Shearwater (Puffinus gavia)

Subspecies

Genus	Species	subspecies	Region	Range
Puffinus	gavia		PO	sw

Genus

Until recently the shearwaters were devided in two genera Calonectris and Puffinus, but based on dna-analysis Penhallurick and Wink (2004) have proposed a splitting of the shearwaters into three genera: Calonectris for the large shearwaters of the Northern Atlantic, the Mediterranean and the waters around Japan, Ardenna for a group of large Southern Hemisphere breeders and Puffinus for the smaller shearwaters such as the Manx’ group, Audubon’s and Little Shearwaters. This new taxonomy is now widely accepted, but not by all and is stil subject of discussion.

Physical charateristics

A medium to small-sized shearwater with uniformly dark brown upperparts (see note). Sides of face and neck grey-brown fading into white well below the eye. Underbody, including undertail coverts, white, except for dark brown thigh patch which shows well in flight. Underwing generally white, but the grey-brown tone of the underwing coverts in axillary region is discernible at close range. The long and slender bill is dark greyish brown. The feet are pale pink with dark outer edges and extend beyond the short rounded tail in flight.

wingspan min.:	74	cm	wingspan max.:	78	cm
size min.:	31	cm	size max.:	37	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 : Southwest. This species is a common and widespread New Zealand endemic. The larger colonies are found in the Three Kings group, Moturoa group, Motuharakeke (Cavalli Islands), north-west Chickens, Bream Islands, Mokohinau group, Channel Island, Mercury group, Ruamahuanui (Aldermen group) and Trio Islands and many other islands in Cook Strait. Fledglings, and Pacific Oceanssibly some adults, move towards the east and south of Australia in February, but most remain near to breeding colonies throughout the year

Habitat

This species breeds on small, vegetated islands and rock stacks. It nests in colonies in burrows under grass, scrub or coastal forest, but occasionally breeds in rocky cavities

Reproduction

The breeding biology of the species is very poorly known, but laying is believed to begin in early September, and chicks fledge from late January

Feeding habits

Birds feed mostly on fish and some coastal krill

Video Fluttering Shearwater

httpv://www.youtube.com/watch?v=UVXkEG9ImqQ

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 very 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.

Fluttering Shearwater status Least Concern

Migration

Partial migrant. Adults apparently fairly sedentary; immatures cross Tasman Sea to winter off SE Australia, where some stay over summer. Rarely occurs E to Chatham Is.