title: Isotopic fractionation in a large herbivorous insect, the Auckland tree weta

authors: Wehi, Priscilla M.

subjects: discrimination factor

abstract: Determining diet and trophic position of species with stable isotopes requires appropriate trophic enrichment estimates between an animal and its potential foods. These estimates are particularly important for cryptic foragers where there is little comparative dietary information. Nonetheless, many trophic enrichment estimates are based on related taxa, without confirmation of accuracy using laboratory trials. We used stable isotope analysis to investigate diet and to resolve trophic relationships in a large endemic insect, the Auckland tree weta (Hemideina thoracica White). Comparisons of isotopes in plant foods fed to captive wetas with isotope ratios in their frass provided variable results, so frass isotope values had limited usefulness as a proxy indicator of trophic level. Isotopic values varied between different tissues, with trophic depletion of 15N highest in body fat and testes. Tissue fractionation was consistent in captive and wild caught wetas, and isotopic values were not significantly different between the two groups, suggesting that this weta species is primarily herbivorous. Whole-body values in captive wetas demonstrated trophic depletion (Δδ) for δ¹⁵N of about–0.77‰ and trophic enrichment of 4.28‰ for δ¹³C. These values differ from commonly estimated trophic enrichments for both insects and herbivores and indicate the importance of laboratory trials to determine trophic enrichment. Isotopic values for femur muscles from a number of local wild weta populations did not vary consistently with body weight or size, suggesting that juveniles eat the same foods as adults. Considerable variation among individuals within and between populations suggest that isotopic values are strongly influenced by food availability and individual foraging traits.

text: Isotopic fractionation in a large herbivorous insect, the Auckland tree weta Determining diet and trophic position of species with stable isotopes requires appropriate trophic enrichment estimates between an animal and its potential foods. These estimates are particularly important for cryptic foragers where there is little comparative dietary information. Nonetheless, many trophic enrichment estimates are based on related taxa, without confirmation of accuracy using laboratory trials. We used stable isotope analysis to investigate diet and to resolve trophic relationships in a large endemic insect, the Auckland tree weta (Hemideina thoracica White). Comparisons of isotopes in plant foods fed to captive wetas with isotope ratios in their frass provided variable results, so frass isotope values had limited usefulness as a proxy indicator of trophic level. Isotopic values varied between different tissues, with trophic depletion of 15N highest in body fat and testes. Tissue fractionation was consistent in captive and wild caught wetas, and isotopic values were not significantly different between the two groups, suggesting that this weta species is primarily herbivorous. Whole-body values in captive wetas demonstrated trophic depletion (Δδ) for δ¹⁵N of about–0.77‰ and trophic enrichment of 4.28‰ for δ¹³C. These values differ from commonly estimated trophic enrichments for both insects and herbivores and indicate the importance of laboratory trials to determine trophic enrichment. Isotopic values for femur muscles from a number of local wild weta populations did not vary consistently with body weight or size, suggesting that juveniles eat the same foods as adults. Considerable variation among individuals within and between populations suggest that isotopic values are strongly influenced by food availability and individual foraging traits.

year: 2010

title: Whatever next? Export market choices of New Zealand firms

authors: Fabling, Richard

subjects: trade

abstract: We examine product and market entry choices of New Zealand exporters, using enterprise-level data on firm performance and merchandise trade. For firms already exporting, we ask: What determines their choices about what and where to export? General and specific prior trade experience play an important role in determining firms' future export activities, as do the export activities of other firms in the local area (a learning effect). These results are robust to the inclusion of other export determinants, including the macroeconomic performance of destination countries, exchange rate movements, and the past performance of the exporting firm.

text: Whatever next? Export market choices of New Zealand firms We examine product and market entry choices of New Zealand exporters, using enterprise-level data on firm performance and merchandise trade. For firms already exporting, we ask: What determines their choices about what and where to export? General and specific prior trade experience play an important role in determining firms' future export activities, as do the export activities of other firms in the local area (a learning effect). These results are robust to the inclusion of other export determinants, including the macroeconomic performance of destination countries, exchange rate movements, and the past performance of the exporting firm.

year: 2011

title: Nā Wai Koe? Our tūpuna call us home: Maremare whānau thinking about connections to whenua tupuna

authors: Sampson, Jasmine

subjects: Whenua Tūpuna

abstract: This research focuses on the Maremare whānau from Tiniwaitara Marae, Turakina, in order to explore the importance of our relationship with our whenua tupuna and the related concept of returning home. 

Although many academics have carefully attended to the concept of ‘disconnection’ from whenua tupuna in order to describe the effects of Māori mobility, this term unfortunately reinforces the colonial attempt to detach our people from the things that provide us with our sense of belonging. I argue that thinking about relationship with whenua tupuna through terms like ‘disconnection’ and ‘reconnection’ are unhelpful and problematic; instead, when we understand this relationship in Māori terms, our connection to our whenua tupuna is an everlasting relationship that is woven into the fabric of our whakapapa.

The research combines interviews with three generations of the Maremare whānau, including people with diverse experiences of relationships with Turakina, with critical reflection on relevant concepts from Te Ao Māori. Specifically, mobilising a Kaupapa Māori Theory approach, the thesis draws on an oriori, ‘He Oriori mō Wharaurangi’ as the methodology and foundation of this thesis. In this way, the thesis both argues and demonstrates the value of researchers, and in particular kairangahau Māori, look to mātauranga Māori to guide us in our research about Māori topics. This oriori is iwi specific, it holds kōrero tuku iho that pertains to my whakapapa as an uri of Ngā Wairiki Ngāti Apa and it is very relevant to both my kaupapa and the people participating in the rangahau.

Ultimately, whakapapa rests at the core of connection to whenua tupuna. It is the foundation in which we stand and it connects us as a people to the land that birthed us. This thesis looks at the different ways that our tūpuna call us home, the different ‘returning home’ experiences within the Maremare whānau and how people within the whānau view their connection with our whenua tupuna in Turakina. Nā wai koe? Our tūpuna call us home.

text: Nā Wai Koe? Our tūpuna call us home: Maremare whānau thinking about connections to whenua tupuna This research focuses on the Maremare whānau from Tiniwaitara Marae, Turakina, in order to explore the importance of our relationship with our whenua tupuna and the related concept of returning home. 

Although many academics have carefully attended to the concept of ‘disconnection’ from whenua tupuna in order to describe the effects of Māori mobility, this term unfortunately reinforces the colonial attempt to detach our people from the things that provide us with our sense of belonging. I argue that thinking about relationship with whenua tupuna through terms like ‘disconnection’ and ‘reconnection’ are unhelpful and problematic; instead, when we understand this relationship in Māori terms, our connection to our whenua tupuna is an everlasting relationship that is woven into the fabric of our whakapapa.

The research combines interviews with three generations of the Maremare whānau, including people with diverse experiences of relationships with Turakina, with critical reflection on relevant concepts from Te Ao Māori. Specifically, mobilising a Kaupapa Māori Theory approach, the thesis draws on an oriori, ‘He Oriori mō Wharaurangi’ as the methodology and foundation of this thesis. In this way, the thesis both argues and demonstrates the value of researchers, and in particular kairangahau Māori, look to mātauranga Māori to guide us in our research about Māori topics. This oriori is iwi specific, it holds kōrero tuku iho that pertains to my whakapapa as an uri of Ngā Wairiki Ngāti Apa and it is very relevant to both my kaupapa and the people participating in the rangahau.

Ultimately, whakapapa rests at the core of connection to whenua tupuna. It is the foundation in which we stand and it connects us as a people to the land that birthed us. This thesis looks at the different ways that our tūpuna call us home, the different ‘returning home’ experiences within the Maremare whānau and how people within the whānau view their connection with our whenua tupuna in Turakina. Nā wai koe? Our tūpuna call us home.

year: 2021