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Applying structured decision making for large-scale wildlife management programmes : Project Janszoon as a case study : a thesis presented in partial fulfilment for the degree of Doctor of Philosophy in Conservation Biology at Massey University, Palmerston North, New Zealand
(Massey University, 2024-11-30) Kenup, Caio
Managing threatened populations is challenging due to the delicate balance between urgency and uncertainty. While swift action is often needed to prevent further decline or extinction, significant uncertainty frequently surrounds the effectiveness of various management strategies and the future trajectory of populations. This uncertainty complicates the identification of the most effective course of action, especially when resources are limited. Structured decision making (SDM) is an approach that supports informed decision making in the face of uncertainty in conservation projects. The primary aim of this thesis is to develop a decision making framework for Project Janszoon’s bird translocations, guiding management and monitoring decisions to maximise establishment and persistence probabilities for the kākā (Nestor meridionalis) and pāteke (Anas chlorotis). This framework can serve as a blueprint for implementing SDM and adaptive management (AM), promoting their broader use in conservation initiatives within New Zealand and beyond. In Chapter 2, I discuss expert elicitation techniques for generating predictions from expert knowledge while accounting for epistemic uncertainty. Numerical improvements in handling elicited data are proposed, focusing on aggregating and transforming expert-provided values while maintaining their associated uncertainty. Preserving this uncertainty is critical to avoid generating overconfident predictions from expert judgment. In Chapter 3, I explore which uncertainties are worth reducing and to what degree. Value of information (VOI) analysis offers a way to understand how reducing uncertainty affects decision making and conservation outcomes. A key insight from this chapter is that while monitoring is valuable for reducing uncertainty, such reductions do not always improve conservation outcomes. Beyond a certain point, further reductions in uncertainty do not alter decision making. Practitioners must estimate the optimal level of monitoring for each conservation challenge. In Chapter 4, I outline a passive adaptive management framework to reduce uncertainty as management actions are implemented and monitored. The framework’s extendable nature makes it adaptable to other management problems. The tools and concepts presented here are valuable assets for effective decision making for managed populations under uncertainty.
Predator-prey interactions in subtropical forest and ecology and conservation of swamp deer or barasingha (Rucervus duvaucelii duvaucelii) : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Conservation Biology at Massey University, Auckland, New Zealand
(Massey University, 2021) Yadav, Hemanta Kumar
The tiger, an apex predator, is an indicator of a healthy ecosystem. Therefore, the conservation of this immensely important umbrella species necessitates ecological knowledge on its interaction with co-predators and status of significant prey species sharing the habitat. Royal Bengal tiger (Panthera tigris tigris) and common leopard (Panthera pardus fusca) are two sympatric carnivores in suitable habitats of the Indian subcontinent where sympatric ungulates cervids are prevailing as major prey species. This thesis investigated the diet overlap of these sympatric apex predators and the population status of prey species in the subtropical lowland landscape popularly known as Terai Arc Landscape (TAL), Nepal. This thesis further explored ranging behaviour, habitat preference, movements, conservation genetics and food habits of the swamp deer or barasingha (Rucervus duvaucelii duvaucelii), the largest cervid prey species of tiger in the western portion of TAL, Nepal. The line transect survey revealed high density and biomass of major cervid prey species compared to other tiger bearing protected areas, with large-sized swamp deer, medium-sized spotted deer (Axis axis) and hog deer (Axis porcinus) being main prey species. Scat analysis revealed that wild ungulates were the main food of both predators. Large-sized wild preys (mainly swamp deer) were found more frequently in tiger scats, and domestic cattle were found more frequently in leopard scats. Both predators consumed the medium-sized spotted deer in high proportions resulting in a high diet overlap. Swamp deer played a critical role in diet partition between the two cats. Dominant tigers displaced leopards to the degraded fringe habitat where the latter subsisted on the domestic livestock, a major cause of human-wildlife conflict. The monitoring of nine radio-collared swamp deer showed a high 95% Minimum Convex Polygon (MCP) and 95% Fixed Kernel (FK) home ranges compared to other sympatric ungulates such as spotted deer, hog deer, and barking deer (Muntiacus muntjac). There was no significant variation in 95% FK annual home ranges between sexes and across three seasons. Overall, the grassland was the most preferred habitat of swamp deer in all the seasons, and the dense Sal (Shorea robusta) forest was the least preferred. In the monsoon season, the moderately dense Sal forest followed the grassland. Within grassland, swamp deer preferred Imperata cylindrica assemblage followed by Imperata cylindrica – Narenga porphyrocoma and Narenga porphyrocoma assemblage. A range shift from the grassland to the Sal (Shorea robusta) forest, only during the monsoon season, indicated that the grassland had reached the carrying capacity during this season. The radio-collared swamp deer crossed the international border. During the rutting season, they consistently used contiguous habitat patches of Lagga-Bagga area of Pilibhit Tiger Reserve, India, thus emphasising the need for transboundary cooperation to conserve this species. The genetic variability, population structure and effective population size of Shuklaphanta National Park (SNP) and Bardia National Park (BNP) populations of swamp deer were examined using the mitochondrial (mt) DNA and microsatellite markers. The analysis revealed moderate to high genetic diversity compared to other swamp deer populations in India. Neutrality tests, which are used to evaluate demographic effects, did not support population expansion. The multimodal pattern of mismatch distribution indicated that both swamp deer populations are under demographic equilibrium. Furthermore, population bottleneck analysis indicated no signature of a bottleneck for both populations. Bayesian cluster analysis and population differentiation test revealed two population clusters with low population differentiation. The effective population size in BNP was below 50, which is often regarded as a threshold below which inbreeding depression is likely to occur. It is recommended to design and implement an effective conservation strategy to enhance the genetic diversity and increase the population size of swamp deer in BNP through an in-situ conservation program and translocation of some breeding individuals from SNP to BNP. Faecal microhistological analysis of swamp deer, sympatric hog deer, and spotted deer from both grassland and the Sal forest habitats revealed that graminoids constituted the majority of the diet of these species in both habitats. However, the proportion of woody plants in diets of spotted deer was significantly higher than the other two. Apart from the graminoids, woody plant Shorea robusta and herb Phoenix humilis were major plant species consumed in the Sal forest. Among graminoid species, early successional tall grasses, especially Saccharum spontaneum, were the dominant food of all three deer species in both habitats. The importance of early successional tall grasses in their diet emphasised the key role of the threatened alluvial floodplains in conserving threatened mammal species in South Asia. Swamp deer foraged more in late succession tall grasses (Saccharum narenga and Themeda spp.) and short grasses (Imperata cylindrica, Cyperus spp., Chrysopogon zizanioides, Cymbopogon spp.) than hog deer and spotted deer. Despite the similarity of their diet, the three ungulates coexisted through differential consumption of plants species and seasonal habitat partitioning.
Conservation status and demographics of the Galapagos land iguana (Conolophus subcristatus) in the Galapagos Islands, Ecuador : a thesis presented in partial fulfilment of the requirements for the degree of Masters of Natural Science in Conservation Biology, Massey University, New Zealand
(Massey University, 2019) Kumar, Kirtana
In conservation biology, understanding the basic demography of populations across their range, provides opportunities to identify and prioritise management actions to improve the conservation of both, populations and of the species as a whole. The Galapagos land iguana or land iguana (Conolophus subcristatus) (endemic to the Galapagos Islands), is an ideal model to explore these ideas and to generate information that can assist its conservation. Currently, the species is classified as IUCN: Vulnerable. Land iguana populations are threatened by introduced species and habitat loss but the intensity of these threats varies between populations. The population sizes across the species range are partially known and suspected to relate to the presence/absence of introduced predators. Although demographic trends are virtually unknown, it is suspected that populations in disturbed areas have a lower recruitment of juveniles and limited population growth. Overall, these gaps in knowledge represent a challenge to a formal evaluation of the species’ conservation status. Historically, translocation of land iguanas to predator-free or predator-managed sites in the Galapagos Islands has played an important role for its conservation. Since the 1970s there have been calls for translocating land iguanas to Santiago Island, considered to harbour one of the largest land iguana populations until the early 1900s. Although the mechanism for the extinction of the Santiago Island population is not understood, it is most likely linked to habitat changes driven by humans and the effects of introduced predators, which are common denominators in significant iguana population declines on other islands around the world. Since the early 2000s, introduced predators have been eradicated on Santiago Island, and the possibility of reintroducing land iguanas there has resurfaced with greater intensity. While the habitat on Santiago Island is considered suitable for land iguanas, and the expertise to handle and transfer these organisms exists there are missing gaps in knowledge in particular: is the size of historically translocated populations comparable to undisturbed populations? What are the current population sizes of land iguana populations? and what are the effects of introduced predators on land iguana populations? This thesis addresses these gaps in land iguana demography by providing an update of the current conservation status, estimates of population size and an analysis of the effects of feral cats using historical data. I examined the effects of feral cats on two populations by comparing historical demographic data from cat-absent and cat-present populations. I found cat-present populations exhibited significantly different population structure and morphology to cat-absent populations, including significantly lower juvenile percentage indicating reduced juvenile recruitment as a result of juvenile depredation . Further, I studied a translocated population of land iguanas (North Seymour) and the most undisturbed land iguana population in one of the most active volcanoes worldwide; Fernandina Island. I estimate and compare population size to assist the planning of a reintroduction of the species to Santiago Island. Finally, I review the IUCN status of the species and conclude that the Vulnerable status is justified, primarily due to its limited geographic range and projected population decline. Four weeks before the completion of this thesis, the Directorate of the Galapagos National Park, Island Conservation and Massey University completed a transfer of over 2000 land iguanas to Santiago Island based on the information provided in this document. Although I could not incorporate the posttranslocation monitoring of land iguanas as part of my thesis, I discuss future research needs that will contribute to the restoration of Santiago Island, and the conservation of land iguanas across their range.
Estimating the population size of two critically endangered South Pacific parakeets : the Tasman Parakeet and Malherbe's Parakeet : a thesis submitted in partial fulfilment of the requirements for the degree of Master of Science in Conservation Biology, Massey University, New Zealand
(Massey University, 2018) Skirrow, Michael John Adam
The Cyanoramphus parakeets are a cryptically coloured group of birds that are distributed across the islands of the South Pacific region. Due to their restricted range and island distributions, species belonging to this genus are considered vulnerable to extinction. However, the extent to which these parrot species are threatened is difficult to determine due to an absence of accurate and reliable population estimates. This research aims to contribute to the conservation of two critically endangered Cyanoramphus parakeets by evaluating the survey methods currently used to estimate population densities. This thesis details the precision and efficiency of distance sampling methods used for monitoring low density parrot populations on small islands. Specifically, examining the annual variation in population size for the critically endangered Tasman Parakeet (Cyanoramphus cookii) and their introduced competitor, the Crimson Rosella (Platycercus elegans), to evaluate the effectiveness of conservation management and species control on Norfolk Island. In addition, the size of three translocated populations of the critically endangered Malherbe’s Parakeet (Cyanoramphus malherbi) were examined to identify if this endemic New Zealand parrot requires further management. Of the distance sampling methods used to monitor parrots, the fixed point survey method was the most suitable method for surveying Tasman Parakeets. This method yielded the highest number of parakeet detections per survey and offered the greatest count precision of the methods examined. On Norfolk Island, the Tasman Parakeet population increased by 126% over four years of intense predator management and nest provisioning. In comparison, the Crimson Rosella population remained stable, despite regular culling to control the population which competes with the Tasman Parakeet. In New Zealand, Malherbe’s Parakeets were detected with varying degrees of success. On Maud Island, no parakeets were detected; however, they were detected on both Blumine Island and Chalky Island. On Blumine Island, the Malherbe’s Parakeet population was moderately abundant, consisting of 202 ± 67 individuals distributed through the mature forest. In comparison, the Chalky Island population of Malherbe’s Parakeet was less extensive and consisted of 84 ± 58 parakeets. This research illustrates the importance of regularly monitoring the size of threatened parrot populations for conservation.
The urban release of captive-reared Kaka at Karori Wildlife Sanctuary : a thesis presented in partial fulfillment of the requirements of the degree of Master of Science in Ecology at Massey University, Palmerston North
(Massey University, 2004) Belcher, Sara
This study investigates the first reintroduction of captive-reared Kaka (Nestor meridionalis), an endangered parrot endemic to New Zealand, at Karori Wildlife Sanctuary, a predator free privately run sanctuary in the same vein as the Department of Conservation's mainland islands. Three Kaka from Auckland Zoo and three Kaka from Hamilton Zoo were released into Karori Sanctuary in August 2002 and followed until August 2003. The Kaka were fitted with radio transmitters, and coloured bands before release. Before release, the consumption of supplementary foods was monitored and the Kaka were introduced to natural foods. The Kaka showed no significant temporal trends, and no correlation between the two groups. The Kaka showed marked preferences for some foods and very varied consumption of others. The Kaka instinctively foraged on natural foods that were provided. Provisioning of natural foods may have reduced neo-phobic responses and assisted successful transition to the wild. Five of the six Kaka remained at the sanctuary 13 Months after release. The Hamilton Kaka tended to disperse further than the Auckland Kaka. All the Hamilton Kaka left the valley where as non of the Auckland birds did. RP-P left the valley and few to Island Bay eventually to return, RR-P went west to beyond Makara peak, and RW-P is the only Kaka to leave and not return. An un-banded wild male arrived at the sanctuary in January 2002 and has reminded since. RP-P and P-WY nested in December 2003 and 3 chicks fledged in March 2003, the pair nested again in 2004 along with RR-P and P-WB. The largest part of the Kaka activity budget is foraging. Supplementary food is a large part of the Kaka diet and the more time a bird spent foraging on natural foods the less time they spent at the feeder. The Kaka at Karori developed a unique location call, and there was evidence of this being taught to the Auckland Kaka by the Hamilton Kaka. Use of the feeder was taught to the wild Kaka that arrived and to the chicks. These results suggest that captive-reared Kaka adapt well to release and supports Berry's (1998) findings. Captive-reared Kaka showed an ability to forage effectively on natural foods, had a high level of site fidelity, and formed stable population. Using captive-reared Kaka is an effective management tool, and the presence of an urban environment did not reduce the success of the release.
The economic implications of a multiple species approach to bioeconomic modelling : a thesis presented in partial fulfilment of the requirements for the degree of Master of Applied Economics at Massey University, Palmerston North, New Zealand
(Massey University, 2002) Fleming, Christopher Mark
Human activity frequently leads to the endangerment or extinction of other species. While ecologists study the biological facets of species loss, economics, as the science of understanding people's behaviour, has been charged with investigating the incentives underlying the actions people take that lead to this loss. One approach economists have taken to gain this understanding is to develop models of endangered species that include both economic and biological components, known as bioeconomic models. While ecologists frequently note the importance of modelling entire ecosystems rather than single species, most bioeconomic models in the current literature focus only on a single species. This thesis addresses the economic significance of this assumption through the development of a series of multiple species models and demonstrates, using African Wildlife as an example, the importance of interrelationships and economic values to the survival of endangered species. From these models one can infer the conditions under which a single species model may be appropriate, at least in general terms. If species are independent, and either the opportunity cost of capital or the value of habitat is very low relative to the value of the species in question, then a single species model may yield results similar to that of a multiple species model. In contrast, if species are independent and these additional conditions are not met, a single species model may significantly underestimate both optimal stock levels and land allocation. However, species do not live independently; they interact with species with which they share habitat and, when species interact, the potential for misapplication of the single species framework is even greater. When species compete, the single species framework consistently produces higher stock levels than the multiple species framework, the greater the level of competition the greater the difference. In a predator-prey relationship, the relative values of predator and prey are critical to determining the outcome of the multiple species model. It is demonstrated that the inclusion of at least all economically valuable species in an ecosystem is important when constructing bioeconomic models. Using single species models where multiple species are economically significant could lead to misleading results and ultimately to incorrect policy decisions.
The ecology and conservation of Latrodectus katipo, New Zealand's endangered widow spider : a thesis presented in partial fulfillment of the requirements for the degree of Masters of Science in Ecology at Massey University
(Massey University, 2006) Costall, Jessica Anne
New Zealand has two endemic widow spider species; Latrodectus katipo Powell, 1871 and L. atritus Urquhart 1890. This study focused on the population dynamics and habitat usage of L. katipo, which has undergone serious decline in its abundance and range over the last thirty years. Previous population studies have not included male or juvenile katipo because of their smaller size. A survey of katipo populations was conducted along the Manawatu coastline. There was considerable variation in population density and structure between sites. The highest katipo population density of 21.8 per hectare was recorded at Koitiata. Koitiata, Himatangi, Foxton and Tangimoana populations had a large proportion of juveniles. At Wanganui South and Castlecliff beaches no juveniles could be found, suggesting that reproductive output is very low and that these sites may require conservation attention. Accurate monitoring is critical to the management of any endangered species, however katipo are not monitored regularly in most areas as current population monitoring methods (transect or quadrat searches) are time and labour-intensive, and require highly-trained observers. I investigated the use of artificial cover objects (ACOs) which have a number of advantages over current monitoring methods; in particular they can be quickly and easily checked by observers. Katipo populations at three sites at Himatangi Beach were monitored between January and July, 2005. More traditional habitat searches were completed concurrently to provide population density estimates. The occupancy rate of the ACOs was strongly correlated with population density, and ACOs are therefore proposed as a reliable alternative monitoring method for katipo. The habitat searches showed that katipo have a longer breeding season at Himatangi than reported in South Island based studies, with males and newly hatched juveniles being found in the field up until about June, as opposed to just during summer months. The katipo population density was relatively constant between January and July, 2005, compared to that of Steatoda capensis, an introduced South African spider. Choice experiments were conducted to investigate whether katipo have preference for certain plant species or driftwood as web sites. Native sand-binding shrubs such as Coprosma acerosa are favoured by katipo over other plant species for web construction, and the exotic grass Ammophila arenaria is avoided by katipo even when growing at low densities. L. katipo spiderlings were raised in the laboratory to observe their development. Katipo eggsacs typically produce about 80 spiderlings, however eggsacs I studied contained between 40 and 146 spiderlings. There is substantial variation in the growth rates and abdominal markings of katipo spiderlings during development. Manawatu katipo are unique in that they often retain large areas of white abdominal markings at maturity.
Foraging ecology of the world's only population of the critically endangered Tasman parakeet (Cyanoramphus cookii), on Norfolk Island : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Conservation Biology at Massey University, Auckland, New Zealand
(Massey University, 2016) Waldmann, Amy
I studied the foraging ecology of the world’s only population of the critically endangered Tasman parakeet (Cyanoramphus cookii) on Norfolk Island, from July 2013 to March 2015. I characterised, for the first time in nearly 30 years of management, the diversity of foods consumed and seasonal trends in foraging heights and foraging group sizes. In addition to field observations, I also collated available information on the feeding biology of the genus Cyanoramphus, to understand the diversity of species and food types consumed by Tasman parakeets and their closest living relatives as a function of bill morphology. I discuss my findings in the context of the conservation of the Tasman parakeet, specifically the impending translocation of the species to Phillip Island. I demonstrate that Tasman parakeets have a broad and flexible diet that includes seeds, fruits, flowers, pollen, sori, sprout rhizomes and bark of 30 native and introduced plant species found within Norfolk Island National Park. Dry seeds (predominantly Araucaria heterophylla) are consumed most frequently during autumn (81% of diet), over a foraging area of ca. 90 hectares, at 6.94 m above the ground. During winter, consumption of dry seeds remains high (61%) however over less than half the foraging area of autumn (46 hectares). More importantly, foraging height during winter is significantly lower than any other season, at 2.16 m. Though overall 18% of all foraging registered occurs at ground level, the highest frequency occurs during winter (55.4%). I argue that this seasonal shift in foraging area and height has important consequences for the management of Tasman parakeets. In particular foraging close to the ground within a small area makes the world’s only population of Tasman parakeets highly vulnerable to predation by introduced cats, thus intensification of cat control during this period is crucial for safeguarding this species in situ.
Developing monitoring methods for cryptic species : a case study of the Australasian bittern, Botaurus poiciloptilus : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Ecology at Massey University, Manawatū, New Zealand
(Massey University, 2016) Williams, Emma M
Difficult-to-detect species (here-after, ‘cryptic’) are problematic to monitor. This is because sampling is often restricted by logistic complications, and species-detectability tends to be low and/or highly variable. Such challenges create data that are complex to interpret, and contain biases that cannot be estimated, making results less meaningful. Yet there is a need to monitor such species as they are also often rare. In this thesis I review 30 publications, covering 28 different species, to demonstrate that challenges experienced across cryptic species fall into four categories: visually-cryptic, behaviourally-cryptic, spatially-cryptic and temporally-cryptic. The Australasian bittern (Botaurus poiciloptilus) is an appropriate case-study for examining the process of developing a monitoring method for cryptic threatened species because they have all four cryptic characteristics. Yet bitterns are also endangered, and what is left of their habitat is under threat. Currently the most feasible monitoring method available for bitterns is counts of male calls (booms) during the breeding season. However, calling-rate is known to be variable and difficulties in accessing some sites restricts sampling possibilities. I fitted a range of generalised linear mixed models to 461 15-min call-counts, conducted in a range of conditions, during two breeding seasons at Whangamarino wetland, to identify factors affecting calling-rate-per-individual-bittern (CRPI). Results showed that CRPI was predictable in terms of time-of-day, time-of-year, cloud-cover, rainfall and certain moon parameters, but some spatial and temporal variation remained unexplained. Additionally, I showed that recorders are a cost-effective practical solution to logistical constraints restricting sampling possibilities at some sites. Furthermore, I show that abundance can be estimated from calling-rate by correcting for effect sizes of factors affecting CRPI. Results obtained using 269 15-min sound-files at two sites (Whangamarino wetland and Lake Whatuma) show that these abundance derivations are accurate but imprecise. To understand more about how call-based methods can be used to monitor bitterns, I radio tracked six males throughout the optimum monitoring-period to confirm that these birds have high site-fidelity, therefore, validating territory-mapping method assumptions. The approach used in this thesis is applicable to any cryptic species, as illustrated with the Guam rail (Gallirallus owstoni) in my final discussion.
Behavioural ecology of the endangered New Zealand Fairy Tern (Tara-iti) Sterna nereis davisae : implications for management : a thesis presented in partial fulfillment of the requirements for a degree of Masters of Science in Ecology at Massey University
(Massey University, 2000) Treadgold, Sara Jane
The roles of the sexes in the New Zealand Fairy Term (Sterna nereis davisae) during reproduction were investigated over the 1997/1999 seasons at Mangawhai and Waipu, Northland, North Island New Zealand. Factors which may affect the behaviour of the birds were investigated including time of season, time of day, weather conditions and the state of the tide. As in other terns, the contributions of the male and the female Fairy Tern to reproduction were relatively equal. Courtship feeding, however, appears to be a male-specific behaviour, and the male feeds the chick more than the female when there is a single chick. The level of care of eggs and chicks at night by the female, and of the fledged young by the male, is unclear, but could alter the overall contribution to breeding by the two sexes. In the first season, wind speed caused less absence from young, while time of day and time of season (week) affected incubation, and parental activities. Egg manipulation for management purposes at Mangawhai altered the birds' behaviour, the female being less attentive during the day and it increased the amount of time birds sat on the nest. The state of the tide affected the feeding of young, with increased feeding three hours after low tide. This may be site-dependent because the Mangawhai Fairy Terns also foraged at high tides. Fairy Terns were highly aggressive towards Harriers, Black-backed Gulls and people, particularly when they had young. Fairy Terns also responded aggressively within 75m, the birds at Waipu responding more often because a number of other birds nested in, and passed over, the area. The Fairy Terns preferred highly elevated nest sites, with low vegetation cover, and a high percentage of shell cover. These features characterise nest sites of a number of terns. DNA analysis suggests that copulation behaviour, but not morphology, is adequate evidence for sexing adult Fairy Terns. The sex ration of nine juveniles was five males: four females. The number of adults caught was too small to calculate an adult sex ratio. This study has implications for future management of Fairy Terns. Eggs at the same development stage should be placed under foster parents, fences should be placed 180m from the nest or chicks, and sparsely vegetated and shell covered areas should be protected and maintainted. Weather conditions, the time of day, and observed absences should be considered before removing eggs from the field. More blood samples are needed for parental and taxonomic studies.

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