[order] PROCELLARIIFORMES | [family] Procellariidae | [latin] Puffinus bulleri | [authority] Salvin, 1888 | [UK] Bullers Shearwater | [FR] Puffin de Buller | [DE] Graumantel-Sturmtaucher | [ES] Pardela Dorsigris | [NL] Bullers Pijlstormvogel
Subspecies
| Genus | Species | subspecies | Region | Range |
| Puffinus | bulleri | PO | widespread |
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 rather uncommon white-bellied shearwater; separated from the two other West Coast white-bellied species by a broad M or W
formed by the contrasting pattern on back and wings. Tail wedge-shaped. Feet pale, but variable.
formed by the contrasting pattern on back and wings. Tail wedge-shaped. Feet pale, but variable.
| wingspan min.: | 97 | cm | wingspan max.: | 99 | cm |
| size min.: | 46 | cm | size max.: | 47 | cm |
| incubation min.: | 48 | days | incubation max.: | 52 | days |
| fledging min.: | 97 | days | fledging max.: | 103 | days |
| broods: | 1 | eggs min.: | 1 | ||
| eggs max.: | 1 |
Range
Pacific Ocean : widespread. Puffinus bulleri breeds only at the Pacific Oceanor Knights Islands, New Zealand. The species is restricted to two main islands, Atlantic Oceanrangi and Tawhiti Rahi, and five other islets and stacks. In the 1980s, one pair was found breeding on the Simmonds Islands, in the far north of New Zealand. Between 1938 and 1981, the Pacific Oceanpulation on Atlantic Oceanrangi increased from c.200 to c.200,000 pairs. The total Pacific Oceanpulation is estimated at 2.5 million birds, but it is unclear whether the Pacific Oceanpulation on Atlantic Oceanrangi is still increasing. It migrates to the northern Pacific Ocean, from Japan to North America and east to California, and is occasionally found off South America.
Habitat
Open ocean.
Tends to concentrate at areas of strong upwelling, or where warm and cool water currents meet, bringing food to the surface. Rarely comes close to shore. Nests on islands with soil suitable for burrows or with crevices among rocky cliffs.
Tends to concentrate at areas of strong upwelling, or where warm and cool water currents meet, bringing food to the surface. Rarely comes close to shore. Nests on islands with soil suitable for burrows or with crevices among rocky cliffs.
Reproduction
Breeds on Poor Knights Islands off North Island, New Zealand. Adults arrive there in September, most eggs laid in late November, young depart in May. Breeds in dense colonies. Adults noisy around colonies at night, may climb up into trees to take flight m
ore easily.
Nest: Site is in burrow under tree r
oots or rocks, or in cave or rock crevice. Both sexes help dig burrow. Nest chamber is lined with leaves, twigs, pebbles. Where birds nest in Maori burial caves, may use human bones as nest material.
Clutch 1 per season. White. Incubation is by both sexes, roughly 51 days.
Young: Both parents feed young, by regurgitation. Period from hatching to departure from nest probably about 100 days, but not well known.
ore easily.
Nest: Site is in burrow under tree r
oots or rocks, or in cave or rock crevice. Both sexes help dig burrow. Nest chamber is lined with leaves, twigs, pebbles. Where birds nest in Maori burial caves, may use human bones as nest material.
Clutch 1 per season. White. Incubation is by both sexes, roughly 51 days.
Young: Both parents feed young, by regurgitation. Period from hatching to departure from nest probably about 100 days, but not well known.
Feeding habits
Crustaceans, fish, squid. Diet not well known. Near breeding grounds may feed mostly on euphausiid shrimp and other crustaceans. Off California, may eat mostly small fish and squid.
Behavior: Food is taken at or just below surface of water. Forages by dipp
ing to surface in flight, plunging into water from a few feet above surface, swimming with head submerged, sometimes upending with head down and tail up. Rarely dives underwater. May feed at night.
Behavior: Food is taken at or just below surface of water. Forages by dipp
ing to surface in flight, plunging into water from a few feet above surface, swimming with head submerged, sometimes upending with head down and tail up. Rarely dives underwater. May feed at night.
Video Bullers Shearwater
httpv://www.youtube.com/watch?v=mzyfmSCb_iM
copyright: Peter Fraser
Conservation
This species qualifies as Vulnerable because the population is restricted to a very small area when breeding, and remains at risk from the accidental introduction of predators and other catastrophes. If it succeeds in expanding its range, it may be downlisted to Near Threatened.
Migration
Breeds northern New Zealand. Fall visitor offshore along our Pacific Coast, mostly from central California north to Washington, rare north to Alaska. Migration:
Breeding adults move north in May, common in parts of North Pacific in summer, returning to New Zealand by September. Seen off our Pacific Coast mainly June to November, most common September-
October; evidently these are mostly non-breeders and immatures.
Breeding adults move north in May, common in parts of North Pacific in summer, returning to New Zealand by September. Seen off our Pacific Coast mainly June to November, most common September-
October; evidently these are mostly non-breeders and immatures.
Distribution map
