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    The anatomy and histomorphology of the uropygial gland in New Zealand endemic species : a thesis presented in partial fulfilment of the requirements for the degree of Master of Zoology at Massey University, Palmerston North, New Zealand
    (Massey University, 2013) Reynolds, Sian
    Considering that there are more than 10,000 species of birds on earth, and that the uropygial gland is the most prominent integument gland in this vertebrate group, it is puzzling that little is known about its morphology and function. The current hypotheses for the function of the uropygial gland can be placed into four groups: 1) feather maintenance; 2) water-proofing; 3) intraspecific communication/health; and 4) defence against predators and/or parasites. Several studies have examined these hypotheses, although no general function for the uropygial gland has been established. This thesis aimed at reducing the gap in knowledge of the uropygial gland by investigating New Zealand birds. The purpose of this study was to examine the anatomical and histological structure of the uropygial gland in New Zealand birds and to investigate the defence hypothesis as a function of the gland specifically in brown kiwi (Apteryx mantelli). Anatomical and histological analyses of the uropygial glands from brown kiwi, great spotted kiwi (Apteryx haastii), hihi (Notiomystis cincta), New Zealand bellbirds (Anthornis melanura), tui (Prosthemadera novaeseelandiae), and saddleback (Philesturnus carunculatus) were carried out. The anatomy and histology of all glands were compared both within family and order and to those available from other species worldwide. The defence hypothesis function of the uropygial gland was investigated using the tick species Ixodes anatis from the skin of brown kiwi. This study revealed a range of uropygial gland characteristics in the kiwi, hihi, New Zealand bellbird, tui, and saddleback that were not know to previously exist in other species. For example kiwi uropygial glands were found to possess eight primary sinuses. Comparison of the New Zealand passerines revealed that bellbirds possess the largest gland in relation to body size out of the four species. The uropygial secretion of brown kiwi may play a role in parasite repellence as both males and female ticks were deterred from the secretion. Based on histomorphology I suggest that rather than a single function, the gland may have species/group functions. However, this hypothesis still remains enigmatic due to the lack of birds studied to date.
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    Resource partitioning between two competitive species, the hihi (Notiomystis cincta) and bellbird (Anthornis melanura), during the non-breeding season on Tiritiri Matangi Island : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Conservation Biology at Massey University, Albany, New Zealand
    (Massey University, 2012) Roper, Michelle
    Understanding the level of competition and resource partitioning between New Zealand’s ecological honeyeaters is important for hihi (Notiomystis cincta) conservation management. Hihi management on Tiritiri Matangi Island has been thought to be hindered by competition with bellbirds (Anthornis melanura), particularly at the supplementary sugar water feeders. With some inconsistent results in differences between their foraging ecology at different locations and seasons, I collected data on the foraging ecology of both hihi and bellbirds on Tiritiri Matangi Island to compare with previous studies at other locations. Nectar was the main constituent of both species diet with fruit only being consumed in the autumn-winter months for both species. The main difference between the species was that hihi consumed more fruit than bellbirds and bellbirds consumed honeydew. Bellbirds foraged more in the higher vegetation layers and on higher nectar value flowers than hihi which corresponded with previous studies. This suggested that resource partitioning is likely to be in the form of bellbirds defending the best resources of higher nectar value in the higher vegetation layers with interference competition and hihi obtain resources with exploitation competition by utilising flowers which are often smaller, less abundant or produce less nectar in the lower vegetation layers. Male bellbirds and hihi were the most frequent visitors to the supplementary feeders. With few interspecific interactions it suggests that male bellbirds are unable to defend the feeders due to the feeders being overwhelmed with hihi and also showing how dependent hihi are on supplementary feeding. Female bellbirds were the least frequent visitors suggesting that intraspecific competition is greater at the feeders but only for bellbirds as there was little evidence of high competition between the hihi sexes. There may be some resource partitioning between habitat types as hihi were consistently found at higher densities in the mature forest habitat likely due to their dependence on the feeders and artificial nest boxes, whereas bellbird densities changed with resource availability and breeding season territoriality. The densities of both species were affected by the presence of feeders and nectar availability with positive correlation between the species in the non-breeding season, suggesting that hihi habitat preference was not affected by competitive exclusion from bellbirds. The removal of 100 bellbirds for a translocation had no evident impact on hihi and bellbird densities at capture sites.
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    Population genetics, biogeography and ecological interactions of the New Zealand bellbird (Anthornis melanura) and their avian malaria parasites : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy (Ph.D.) in Zoology at Massey University, Albany, New Zealand
    (Massey University, 2011) Baillie, Shauna Maureen
    Habitat loss and redistribution of species has lead to population declines and loss of genetic diversity with serious implications to species survival on ecological and evolutionary scales. While there is no doubt that rapidly dwindling endangered populations require our immediate attention, studies on common species are equally important. The purpose of this thesis is to investigate the genetic connectivity, biogeographical relationships and host-parasite interactions of a common and widely distributed bird species, mainly because we want common species to remain common. Furthermore, I illustrate how studies such as this provide invaluable comparisons for sympatric endangered species. In this thesis, patterns of genetic variation of the New Zealand bellbird (Anthornis melanura) are delineated to assess their re-colonization potential among fragmented landscapes. Using a phylogeographic perspective I show how dispersal ability and secondary contact among isolated population fragments shape the evolutionary trajectory of a species. I also determine the biogeographical relationships between the bellbird host and its malaria parasites with key emphasis on host-parasite specificity. Finally, immunological trade-offs are investigated in disease epidemiology by examining host factors that influence malaria prevalence. I show that an immense capacity for dispersal has prevented divergence and shaped the high levels of genetic diversity and connectivity in bellbirds today. However, substantial genetic differentiation among subpopulations reflects recent habitat fragmentation. Based on these findings I conclude that continued habitat loss can lead to further reductions in gene flow, despite dispersal. Though restricted to northern populations, I provide evidence that the most abundant avian malaria lineage infecting bellbirds is likely an endemic Plasmodium (Novyella). This parasite exhibits bimodal seasonality and male-biased infections, but these relationships vary among subpopulations. Malaria prevalence appears to be governed by food availability and territory stability, thus habitat disturbance has repercussions to immune phenotype. With this thesis I advocate a re-thinking of conservation strategies toward spatial planning that enables ‘natural’ secondary contact among habitat fragments. Translocation is not necessary for all species. In addition to being the first study on seasonal and host factors affecting malaria patterns in the Southern Hemisphere, this thesis makes major contributions to science by elucidating some ecological relationships that underpin the evolution of immunity.