Rationale
(Changed due to Criteria revision)
The regional population of Common Diving Petrel Pelecanoides urinatrix satisfies the criterion for regionally Vulnerable under D2 (population with a very restricted area of occupancy or restricted to a small number of locations (typically five or fewer) such that it is prone to the effects of human activities or stochastic events within a very short time period in an uncertain future, and is thus capable of becoming Critically Endangered or even Extinct in a very short time period). However, it was felt that it was unlikely that stochastic events or human activities at the Prince Edward Islands would lead to the Common Diving Petrel becoming Critically Endangered or even Extinct within one to two generations although there was a possibility that such activities could result in the species being listed as Vulnerable or Endangered during that period. As a result it was assessed as regionally Near Threatened.
Distribution
The species has a circumpolar range, breeding on various islands in the Southern Ocean, in four populations, including islands south-east of New Zealand and Australia, southern Indian Ocean islands, Tristan de Cunha and Gough islands, and islands south-west of Chile, including the Falklands and South Georgia islands (Onley and Scofield 2007). These birds are presumed to be sedentary, although large numbers have been reported far from land in the southern Indian Ocean in the early summer (Onley and Scofield 2007).
Population
The global population is estimated to exceed 16 million mature individuals (Brooke 2004). The regional population of the Prince Edward Islands has experienced sharp declines, especially on Marion Island, where domestic cats Felis catus, introduced in 1948, resulted in high predation rates of burrowing petrels (van Aarde 1980). Common Diving Petrels on Marion Island were stated to be ‘widely distributed' in 1951 (Rand 1954); however, previously monitored nests were not recorded in 1965 (van Zinderen Bakker Jr 1971) and Common Diving Petrels were thought to no longer breed on Marion Island by 1971 (Schramm 1986). Barnes and Huyser (1998), however, estimated the breeding population on Marion Island to be less than 25, whereas breeding is only suspected on Prince Edward Island. The regional population size is unknown.
Population trend
The global population is thought to be stable in the absence of any evidence of declines. The regional population trend is thought to be positive due to the removal of domestic cats Felis catus from Marion Island (Cooper et al. 1995). The confidence in this regional trend estimate is medium.
Threats
Predation by introduced cats on Marion Island drove the Common Diving Petrel to local extinction by the 1960s; however, this threat has been removed by eradicating all cats by 1991 (van Zinderen Bakker Jr 1971, Bester et al. 2002). Human disturbance by trampling remains a potential minor threat on Marion Island, although this is tightly controlled (Gremmen et al. 2003).
Conservation
Underway
No species-specific conservation actions are underway, although generic conservation measures are in place at the Prince Edward Islands. In addition, the Prince Edward Islands Marine Protected Area was proclaimed in 2013.
Proposed
None are currently recommended, as there are no overt threats to this species in the region.
Research
* The dearth of information for this species at the Prince Edward Islands is in keeping with the other burrowing petrels, for example basic demographic and life-history information is almost completely lacking, and movements at sea, dispersal of juveniles and meta-population dynamics are unknown.
* Possible predation by introduced mice on chicks of Great-winged Petrel and other burrowing petrels should be fully examined.
