Modeling Harvest Intensity of Sooty Shearwater Chicks by Rakiura Māori in New Zealand

Abstract: Cultural evidence suggests that sooty shearwater (Puffinus griseus) chicks have been harvested by Rakiura Māori on islands in southern New Zealand since prehistoric times. Concerns exist that modern harvests may be impacting sooty shearwater abundance. We modeled human-related and ecological determinants of harvest (total no. of individuals harvested) of sooty shearwater chicks on 11 islands and examined the relationship between shearwater abundance and harvesting rates (chicks/hr) and harvester behavior throughout the harvesting season. Models best explaining variation in harvest between harvesting areas (manu), for both the early and late parts of the harvesting season, included harvester-days (included in all models with change in deviance information criteria [ΔDIC], ΔDIC < 8.36 and ΔDIC < 11.5, for the early and late periods, respectively). Other harvest determinants included shearwater density, size of the manu, and number of people helping harvesters (all included in the top 5 models within ΔDIC = 2.25 for the late period). Areas harvested by several families under a common-property harvesting system had higher harvest intensity for their size (24% points higher, 95% credible interval 11–36%) than those managed as an exclusive resource for one family. The slowest harvesters spent more time harvesting but on average only harvested 36% (95% credible interval 15–65%) and 34% (95% credible interval 12–63%) of the harvest taken by the fastest harvesters during the early and late periods, respectively. Our results highlight the possibility of elevated harvest intensity as the population of harvesters increases. However, our models suggested that a corresponding reduction in harvesting rate at low prey densities during the most productive period could potentially regulate harvest intensity. Future research will integrate these results into prospective shearwater demographic models to assess the utility of a range of harvesting strategies in ensuring harvest sustainability.     

Guidelines for cross‐cultural Participatory Action Research partnerships: A case study of a customary seabird harvest in New Zealand

Abstract

Adaptive co‐management and Participatory Action Research (PAR) promotes social ecological resilience by simultaneously protecting wildlife and its habitat and promoting capacity and motivation for sustainable harvest management by communities. We report here on a case study of learning through a partnership (1994–2009) between science and Traditional Ecological Knowledge (TEK) to determine the sustainability of titi (sooty shearwater, Puffinus griseus) harvests by Rakiura Maori in southern New Zealand. Testimony of Maori elders and titi harvesters (birders), members of the Rakiura Titi Islands Administering Body, researchers and participants in workshops and meetings were recorded throughout the 14‐year research project to identify critical determinants of success of the partnership. A large majority of participants supported the research, mainly because it expanded their knowledge by investigating the reasons for declining bird numbers and the means of ensuring the continuation of their muttonbirding heritage. Initial concerns about the research included fear that prohibition or quota would be imposed through political pressure from external groups; the intrusion of strangers on the islands; the misconception that the research was being promulgated by government regulatory agencies; and scepticism about research findings. Research also precipitated conflict and division within the Rakiura community, and some birders feared that science might displace matauranga Maori (TEK) of the Rakiura people for guiding harvest management. Core conditions for community engagement included trust between parties, effective communication of the science, equitable decision‐making responsibility, and building scientific capability and monetary support to enable meaningful participation. The most fundamental requirement is mutual respect for each party's knowledge. Attention to this inclusive, equitable, slow and prolonged process makes it more likely that the community will uptake results to improve sustainability of harvesting. The research has heightened awareness within the harvesting community of conservation issues facing the titi and of potential options to mitigate them. Eradication or control of weka (Gallirallus australis), and reducing titi harvest levels from around a quarter of the manu (family birding territories), are the main practical ways of increasing sustainability, but the magnitude and direction of climate change impacts on the shearwater population remains uncertain.     

Genetic variation of the sixth component of complement (C6) in the Manx shearwater (Puffinus p. puffinus)

A polymorphism in the sixth complement component (C6) has been investigated by isoelectric focusing. The results indicate that C6 is coded by genes at a single autosomal locus. Six structural alleles have been identified, a null allele is also postulated. Five island colonies of Shearwater were investigated, two alleles C6 A and C6 B predominate in all sites.
The ability of rabbit C5 and C7 to combine successfully with avian C6 indicates the functional sites of these molecules are highly conserved.     

Soil-disturbance by native animals plays a critical role in maintaining healthy Australian landscapes

Summary   Soil-disturbing animals have wide-ranging effects on both biotic and abiotic processes across a number of Australian ecosystems. They alter soil quality by mixing surface soils and trapping litter and water, leading to areas of increased decomposition of organic matter. The foraging pits of indigenous soil-disturbing animals tend to have different soil chemical characteristics, greater levels of infiltration and lower levels of soil density than adjacent areas. Enhanced capture of seeds and water turns disturbance pits into areas of enhanced plant germination. The burrows, pits and mounds of both native and exotic animals provide habitat for a range of vertebrates and invertebrates and contribute to patchiness in the landscape. Given their wide-ranging effects on surface soil and ecological processes, we argue in this review that soil disturbance by native animals has the potential to contribute to restoration of degraded landscapes, particularly in arid and semi-arid areas.     

Identifying mammalian predators from bite marks: a tool for focusing wildlife protection

Dead Sooty Shearwater, Puffinus griseus, chicks and adults were collected from seven colonies on South Island, New Zealand in the 1993–96 breeding seasons. An estimated 97% of 118 deaths were from predation. Thirty‐four definite predator bite pairs were identified on 27 carcasses. Twenty‐one (78%) of the carcasses had bite pairs with intercanine distances < 9.5 mm which suggests that Stoats (Mustela erminea) were the principal predators. One chick was killed by a feral House Cat (Felis catus), and it is likely that feral Ferrets (M. furo) were responsible for a proportion of the deaths. Nearly three quarters of definite Stoat bite pairs were identified in the head region. The analyses of bite marks offers cheap and statistically reliable identification of predators provided carcasses are collected fresh and flesh is removed to examine tooth punctures in bone.     

Colony-Site Selection Drives Management Priorities for Yelkouan Shearwater Populations

Abstract: We tested whether colony-site availability could allow for an increase in the unusually small breeding populations of yelkouan shearwater (Puffinus yelkouan) on the islands of the Port-Cros National Park (France) if feral cat eradication were undertaken. Comparisons between colony and noncolony sites indicated yelkouan shearwaters preferred deep-soiled and low-outcrop-covered coastal sites. A substrate cover, light avoidance, and sea proximity model suggested that 17.5% of unoccupied sites are suitable for colony establishment. The low proportion of suitable sites currently used by yelkouan shearwaters suggests that these colonies could be refuges and that feral cat eradication will probably lead to a breeding population increase.