Invasive mammalian predators are the main threat faced by the Grey-faced Petrel. Cats, Polynesian Rats, Brown Rats, House Rats, stoats and pigs are all thought to cause population declines through nest depredation causing a loss of reproductive success, with cats also taking adults. Eradication efforts have taken place to reduce the population of both cats and Polynesian Rats. The removal of each species from breeding islands resulted in an increase in the population of Grey-faced Petrels (Greene et al. 2015). Cats remain on one breeding island and are present throughout the mainland distribution outside of fenced areas, while Polynesian Rats remain in some areas of its range. Brown Rats and House Rats remain on nine and fourteen breeding islands, respectively. The species is still legally harvested on some offshore islands in the Bay of Plenty and Hauraki Gulf; however, attempts have been made to ensure that current harvest is sustainable (Greene et al. 2015).
Name
Emma Hemmerlé
Scientific Name
Pterodroma gouldi
Common Name(s)
Grey-face petrel
Type of Use
Extractive (i.e., the entire organism or parts of the organism are removed from its environment)
If extractive, for the target species, is this use
Data for our models were originally derived from stud conducted at 2 grey-faced petrel colonies (1 mainl Mauao—Mt Maunganui [37°37' S; 176°10' E] and 1 shore island: Moutohora—Whale Island [36°51' S, 176 E]) located along the east coast of the North Island, Zealand (Jones et al. 2011, 2015£; We based our models on the Moutohora colony because a growing population where a customary harvest of grey faced petrel chicks has recently been re-established (Jo et al. 2015a).
Local people (e.g., individuals, communities, co-operatives)
If more than one box ticked, please provide more details
harvesting by local Maori populations;
Is the use part of a strategy to generate conservation incentives, to finance conservation, or to improve tolerance/stewardship?
Unknown/not recorded
Is there evidence that the use is affecting the conservation status of the species? HIDE
Yes – use is improving the status (e.g., population is increasing or stabilising, extraction effort OR catch per unit effort is decreasing or stable)
Is there evidence that the use is affecting natural selection?
Unknown/not recorded
Is there evidence that the use is affecting poaching of illegal wildlife trade?
Unknown/not reported
results indicated that customary practices for the harvesting of the bird species was likely to be effective in sustaining growing populations of burrow-nesting seabirds;
Is there any evidence that this use of the species is having a knock-on effect on the status of non-target species
Unknown/not recorded
Unknown/not recorded
Details of assessment carried out
The cultural practice of rotating harvests or resting populations was effective; harvesting every 3 years allowed up to 75% of chicks to be taken without causing the theoretical population to decline. Maori's harvesting techniques, such as the harvesting of chicks rather than adults, promote the sustainability of the practice. In addition ,they recognize thresholds where chick survival also becomes important to the long terms survival of populations, and integrate that to their practices; only harvesting the chicks that are within arm's reach inside the burrows further ensures that a sustainable proportional harvest threshold would not be exceeded. rotating harvest among breeding colonies every couple of years also had a positive impact on the growth rate of the grey-face petrel populations.
Has a valuation of financial flows from this use at the site/national/international level been recorded
LYVER, P. O., JONES, C. J., BELSHAW, N., ANDERSON, A., THOMPSON, R., & DAVIS, J. (2015). Insights to the Functional Relationships of Māori Harvest Practices: Customary Use of a Burrowing Seabird. The Journal of Wildlife Management, 79(6), 969–977. http://www.jstor.org/stable/24763902
Threats/pressures impacting the species at the scale of this record