Harvest rate of sooty shearwaters (Puffinus griseus) by Rakiura Māori: a potential tool to monitor population trends?

Abstract

Sooty shearwaters (tītī, muttonbird, Puffinus griseus) are highly abundant migratory seabirds, which return to breeding colonies in New Zealand. The Rakiura Māori annual chick harvest on islands adjacent to Rakiura (Stewart Island), is one of the last large-scale customary uses of native wildlife in New Zealand. This study aimed to establish whether the rate at which muttonbirders can extract chicks from their breeding burrows indicates population trends of sooty shearwaters. Harvest rates increased slightly with increasing chick densities on Putauhinu Island. Birders' harvest rates vary in their sensitivities to changing chick density. Therefore a monitoring panel requires careful screening to ensure that harvest rates of the birders selected are sensitive to chick density, and represents a cross-section of different islands. Though harvest rates can provide only a general index of population change, it can provide an inexpensive and feasible way to measure population trends. Detecting trends is the first step to assessing the long-term sustainability of the harvest.

Knowing by doing: Learning for sustainable muttonbird harvesting

“…For example, during rama, harvesters concentrate their efforts where and when chicks are aggregated (Lyver 2002;Moller et al 2004), which reduces harvesters' ability to monitor long-term population trends. Nanao catch-rate probably has a stronger ability to indicate population trends and is comparable between different generations of birders on the same area (Lyver 2000;Kitson 2004). The loss of the skill to nanao may reduce the efficacy of traditional ecological knowledge to monitor population changes and thus impede sustainable management.…”

Hauraki Maori Matauranga for the conservation and harvest of Titi, Pterodroma macroptera gouldi

“…However, monitoring population baselines and trends in harvest rates and prey abundance can be an important component of matauranga (Usher 2000, Kitson 2004, Moller et al 2004, Gilchrist et al 2005, Lyver et al 2008) . Through harvest-based indicators Hauraki birders were able to provide insights into the decline of the TItI on the Ruamaahua Islands over a 50-60-year timeframe.…”

“…For the Hauraki iwi, matauranga forms the basis of their association with a culturally significant seabird species, the TItI, Grey-faced Petrel, Pterodroma macroptera gouldi (Hutton, 1869). The customary take ofTItI chicks by Hauraki represents one of the three remaining petrel harvests permitted in Australasia (Skira 1990, Kitson 2004.…”

Is the wild rabbit (Oryctolagus cuniculus) a threatened species in spain? Sociological constraints in the conservation of species

“…The best-known example comes from fisheries, where management is primarily based on catch data (Hilborn and Walters 1992). One major concern, however, is that harvest records do not reflect true variations in species abundance (Gilpin 1973), although some studies indicate that correlations may be good (Royama 1992;Cattadori et al 2003;Kitson 2004). Hunting statistics in Spain are available from 1973, and these may be the best data available for the determination of temporal dynamics and trends of game species across the country.…”

“…However, game species show an additional advantage because hunting bag data can be used as a proxy of abundance across time (e.g. Potts et al 1984;Baines and Hudson 1995;Cattadori and Hudson 1999;Kitson 2004). The best-known example comes from fisheries, where management is primarily based on catch data (Hilborn and Walters 1992).…”