The Procellaria petrels represent a group of large and bulky seabirds that can be placed between the shearwaters of the genus Calonectris and the more fulmarine petrels. Until recently the largest of the Procellaria-species, the White-chinned and the only slightly smaller Spectacled Petrel, were considered to be conspecific. Now they are split into two separate species. Both have a large and strong bills, ivory colored with black sulci between the horny plates and ivory colored ungues, the latter sometimes slightly darker in the Spectacled Petrel. The Westland and Parkinson?s Petrel are also two similar species, of which the latter is a smaller version of the first. Both have ivory colored bills (with a bluish tinge in young birds), with blackish ungues. In the Parkinson’s the black is less extensive than in the Westland. There is no overlap in bill measurements. The Westland Petrel is of the same size as the White-chinned and its culmen is always longer than 47.8 mm. That of the Parkinson?s Petrel not longer than 45.1 mm The bill of the somewhat distinct Grey Petrel is about the size of the larger Procellarias, with the same pattern as the White-chinned and pectacled, but instead of ivory, more pearl-grey. The Grey Petrel’s somewhat lighter bill structure comes close to that of the Calonectris species. Because its somewhat different coloration, habits and structure this species formerly formed a genus of its own: Adamastor. It is now considered to belong to Procellaria.
|wingspan min.:||110||cm||wingspan max.:||120||cm|
|size min.:||46||cm||size max.:||48||cm|
|incubation min.:||56||days||incubation max.:||57||days|
|fledging min.:||96||days||fledging max.:||122||days|
Video Black Petrel
copyright: Brooke Clibbon
Procellaria parkinsoni breeds on Great and Little Barrier Islands, New Zealand, where the total population is c.1,300 and 100 breeding pairs respectively, equating to a total population of c.5,000 individuals. The estimate of 1,300 pairs on Great Barrier Island is lower than previously thought but probably reflects improved information rather than a decline, however it is not a complete survey and although it covers the majority of the island’s population further research is needed to assess the true population size. It once bred in the mountains of the North and South Islands, but had disappeared from the mainland by the 1960s. On Little Barrier, it was abundant in the late 1800s but the population was decimated, mainly by feral cats, until predators were eradicated in 1980. The Little Barrier population is now thought to be slowly increasing. On Great Barrier, the population may be stable.