331 research outputs found

    Endemic birds in Papua New Guinea's montane forests: human use and conservation

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    Escalating anthropogenic impacts on tropical biodiversity have amplified the vulnerability of endemic species. Selective harvesting of species is one of the major threats to birds and mammal species in the tropics. Many indigenous cultures, however, have long established cultural associations with certain species. The hunting and trade of species have been mainly for subsistence and socio-cultural ties within their communities. However, contemporary threats associated with human population increase from within such societies and externally driven demand such as wildlife trafficking exacerbate the pressure particularly for vulnerable species. Threats to endemic tropical species are not isolated to one but often synergies between many factors simultaneously affecting changes to species distribution. In addition to immediate anthropogenic impacts such as population pressure exerted on species numbers and species habitats, there is growing evidence that demonstrates that climate change is causing shifts in species distribution. Such cases have been demonstrated in tropical island montane forests. The island of New Guinea is the largest tropical island in the world and accommodates the third largest tropical rainforests. New Guinea has over 600 bird species (195 endemic), but some species are under threat from unsustainable hunting practices, climate change, and landscape modification. The central highlands is one of the most populous areas and has undergone thousands of years of human modification. The biodiversity of the island of New Guinea remains one of the understudied sites in the world. Looming threats necessitate an assessment of the vulnerability of species important to subsistence and culture. This thesis addresses the need for further understanding of the vulnerability of species to anthropogenic impacts associated with hunting and trade and the effects of climate change on endemic montane species. The thesis begins by improving the contemporary understanding of trade of bird species in the central highlands (large scale) of Papua New Guinea. The contemporary costs of species traded were delineated from this study and compared to the known records over 40 years. Next, case study sites (fine scale) were conducted to understand how rural forest communities hunt and trade wildlife and the social nuances that affect their choice and locality of hunting activities. The study then uses species identified from trade and hunting to conduct a vulnerability assessment of species most at risk from selective harvesting. This assessment may also serve as a guide to conservation efforts in the central highlands. Finally, a rare endemic species, Paradisornis rudolphi (Blue Bird of Paradise) was selected from the vulnerability assessment to make predictions of its distribution change due to climate change. Overall, this thesis demonstrates the importance of applying an interdisciplinary approach that is relevant to the region, context of culture, society, and conservation. This study suggests that vulnerable species used in culture are also at risk from effects of climate change. This information, in addition to other extrinsic factors such as land use change (not studied), is vital for conservation of the endemic montane species, as well as the persistence of cultural diversity in New Guinea. There are limitations to this study which include the lack of a better climate model for Papua New Guinea. The species distribution model should serve as a conservative prediction of the outcome of a rare endemic species. However, even with a conservative approach, there is indication of the need for proactive approaches at the rural and national levels. A way forward would be to consider means of income generation that also support the conservation of species, such as eco-tourism. At the policy level, there is a need to revise the policy to reflect species management and the enforcement of monitoring of unlawful trade particularly those that may be destined for international markets

    Using Global Positioning Systems (GPS) and temperature data to generate time-activity classifications for estimating personal exposure in air monitoring studies: an automated method

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    Background: Personal exposure studies of air pollution generally use self-reported diaries to capture individuals’ time-activity data. Enhancements in the accuracy, size, memory and battery life of personal Global Positioning Systems (GPS) units have allowed for higher resolution tracking of study participants’ locations. Improved time activity classifications combined with personal continuous air pollution sampling can improve assessments of location-related air pollution exposures for health studies. Methods: Data was collected using a GPS and personal temperature from 54 children with asthma living in Montreal, Canada, who participated in a 10-day personal air pollution exposure study. A method was developed that incorporated personal temperature data and then matched a participant’s position against available spatial data (i.e., road networks) to generate time-activity categories. The diary-based and GPS-generated time-activity categories were compared and combined with continuous personal PM2.5 data to assess the impact of exposure misclassification when using diary based methods. Results: There was good agreement between the automated method and the diary method; however, the automated method (means: outdoors = 5.1%, indoors other =9.8%) estimated less time spent in some locations compared to the diary method (outdoors = 6.7%, indoors other = 14.4%). Agreement statistics (AC1 = 0.778) suggest ‘good’ agreement between methods over all location categories. However, location categories (Outdoors and Transit) where less time is spent show greater disagreement: e.g., mean time “Indoors Other” using the time-activity diary was 14.4% compared to 9.8% using the automated method. While mean daily time “In Transit” was relatively consistent between the methods, the mean daily exposure to PM2.5 while “In Transit” was 15.9 ÎŒg/m3 using the automated method compared to 6.8 ÎŒg/m3 using the daily diary. Conclusions: Mean times spent in different locations as categorized by a GPS-based method were comparable to those from a time-activity diary, but there were differences in estimates of exposure to PM2.5 from the two methods. An automated GPS-based time-activity method will reduce participant burden, potentially providing more accurate and unbiased assessments of location. Combined with continuous air measurements, the higher resolution GPS data could present a different and more accurate picture of personal exposures to air pollution

    Ecology and Conservation of Parrots in Their Native and Non-Native Ranges

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    This book focuses on parrots, which are among the most fascinating, attractive, and threatened birds, combining and synthesizing recent research on the biology, ecology, and conservation of both native and non-native parrot populations across the world

    The Aalborg Survey / Part 4 - Literature Study:Diverse Urban Spaces (DUS)

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    Evaluating citizen science for dialect research on the nightingale song (Luscinia megarhynchos)

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    Citizen Science (CS) ist eine Methode, die in den letzten Jahren in der Wissenschaft weltweit an Bedeutung gewonnen hat. Obwohl viele Studien diese Daten mit denen von akademischen Forschenden verglichen, gibt es immer noch Bedenken hinsichtlich ihrer QualitĂ€t. In meiner Doktorarbeit zielte ich darauf ab die Methode CS fĂŒr eine Vogelart mit einem großen Repertoire, der Nachtigall (Luscinia megarhynchos), als Anwendungsfall auf der Grundlage der Dialektforschung zu evaluieren. Ich untersuchte, ob die drei vermeintlichen HauptgrĂŒnde fĂŒr schlechte QualitĂ€t (AnonymitĂ€t, Unerfahrenheit und fehlende Standardisierung) zu unvollstĂ€ndigen, zeitlich oder rĂ€umlich verzerrten und ungenauen bioakustischen Daten fĂŒhrten. Dazu analysierte ich nicht-standardisierte CS-Aufnahmen, die mit einem Smartphone ĂŒber die 'Naturblick' App erstellt wurden, welche einen eingebauten Mustererkennungsalgorithmus enthielt. Ich konnte in meiner Doktorarbeit zeigen, dass mit der Methode CS valide Daten fĂŒr die bioakustische Forschung gewonnen werden können. Meine Ergebnisse zeigten, dass AnonymitĂ€t, mangelnde Erfahrung und Standardisierung nicht zu geringer QualitĂ€t fĂŒhrten, sondern zu einem großen Datensatz, der genauso wertvoll war wie jene von akademischen Forschenden. Die Ergebnisse sind von großer Bedeutung fĂŒr kĂŒnftige CS-Projekte zur Verbesserung der QualitĂ€t und des Vertrauens in diese Daten.Citizen science (CS) is a method that has been increased in science worldwide in recent years. Although many studies have compared these data with those of academic researchers, there are still concerns about their quality. In my doctoral thesis I aimed to evaluate the method of CS for a bird species with a large repertoire, the nightingale (Luscinia megarhynchos), as a use case based on dialect research. I investigated whether the three main assumed reasons for poor quality (anonymity, inexperience and lack of standardisation) led to incomplete, temporal or spatial biassed and inaccurate bioacoustic data. Therefore, I analysed non-standardised CS recordings, which were generated with a smartphone via the 'Naturblick' app, which contained an in-built pattern recognition algorithm. In summary (Chapter V), my doctoral thesis showed that the method CS could be used to generate valid data for bioacoustic research. My findings showed that anonymity, lack of experience and standardisation did not lead to low quality but in fact to a large dataset, which was as valuable as ones from academic researchers. The results are of great relevance for future CS projects to improve the quality and the trust in these data

    Population viability and conservation of grey parrots psittacus erithacus on the island of PrĂ­ncipe, Gulf of Guinea

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    Parrots are among the most endangered birds in the world, owing to the international pet trade, and habitat degradation. Grey Parrot Psittacus erithacus, the most traded wild-caught species, has suffered a steep decline across its vast African range. This PhD investigates Grey Parrot’s ecology to understand the mechanisms by which harvest and habitat loss affect populations. The island of PrĂ­ncipe was chosen as a study area owing to its healthy Grey Parrot population, its tradition of parrot harvest and the disturbed-to-pristine range of habitats. Parrot densities were exceptionally high (mean±SE: 53±3 parrots km-1), and their distribution within the island was shown to change significantly between pre- and post-breeding season. The presence of nest tree species was the best predictor of densities in the former (F=2.99, p=0.07), while slope and food tree species were in the latter (F=3.0, p<0.05 and F=8.04, p<0.01). Variation in habitat use across seasons highlights the importance of opportunely timed surveys, and the need of preserving a matrix of habitats. Three simple and inexpensive methods were tested, which may be useful where more precise methods cannot be used. Simple encounter rates were shown to be a workable proxy for actual densities: a relationship was found between the two (R2=0.8, df=9, p=0.01). Long watches proved to be far less accurate and suitable only in limited cases (i.e. enough vantage points overlooking small areas and numerous encounters). Counts along flyways were suggested to be a good monitoring method, although further testing is required. Nest densities were found to be very high (mean±SE: 16.8±7.9 and 72.4±26.2 nests km-2 in secondary and primary forest respectively) compared to those elsewhere. The habitat characteristics measured didn’t affect productivity, suggesting that cavity characteristics may be more important. The best demographic data available on the species, were used to build a Population Viability Model to investigate its population dynamics in the face of harvest and habitat loss. In PrĂ­ncipe, Grey Parrots were shown to have increased rapidly after a trade ban was put in place, highlighting the recovery potential of the species. Harvest alone was shown to be harmless only when small quotas (e.g. 600 chicks year-1) are yielded from large populations, while habitat loss lowered the predicted maximum population size. The interaction of these threats can be much more unpredictable. The effects of harvest are worsened if poorly regulated or techniques that include the harvesting of adults are used. Extinctions were predicted to occur with significant delay (≄40 years), and the conservation implications were discussed. Finally, the contribution of this thesis to the understanding of Grey Parrots ecology and conservation is highlighted and research priorities identified

    Foraging resource use by grey-headed flying-foxes in urban and non-urban Australia

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    Urbanisation is a major threat to ecosystems globally, resulting in habitat loss and habitat fragmentation, reduced biodiversity, and/or species extinction. However, urban habitats also create opportunities for exploitation by adaptable species, and this often leads to unbalanced management actions that have little regard for species conservation. Better understanding of the underlying drivers of wildlife species urbanisation will assist wildlife managers in developing effective and balanced conservation-management strategies. The grey-headed flying-fox (Pteropus poliocephalus), is a large, highly mobile species, that is becoming increasingly dependent on urban areas. Flying-fox urbanisation has been hypothesised to be a result of loss of natural foraging habitat, an attraction to increased spatiotemporal stability of food resources in urban areas, and/or both. Yet, little is known about how P. poliocephalus utilise urban areas for foraging. This study aims to investigate foraging resource availability as a driver of the documented P. poliocephalus urbanisation. Foraging habitat use was assessed using a large satellite tracking dataset from 98 individuals between 2012-2017. These data were combined with vegetation type data, and published indices of P. poliocephalus habitat quality to assess foraging habitat preferences. Tracked individuals were overwhelmingly dependent on human-modified landscapes for foraging, particularly where they roosted in major-urban areas. To identify the specific food plant species that support P. poliocephalus in urban areas, paired GPS and accelerometer data were used to identify trees visited by foraging individuals roosting in Adelaide. Tracked individuals preferentially visited residential areas and road-side habitats. Individuals visited a relatively high diversity of food plant species in these habitats, and flowering/fruiting phenology records indicated collective year-round availability of food resources for P. poliocephalus. This study suggests that P. poliocephalus urbanisation is, at least in part, driven by spatiotemporal availability and stability of food resources

    Population modelling and genetics of a critically endangered Madagascan palm Tahina spectabilis.

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    Madagascar is home to 208 indigenous palm species, almost all of them endemic and >80% of which are endangered. We undertook complete population census and sampling for genetic analysis of a relatively recently discovered giant fan palm, the Critically Endangered Tahina spectablis in 2008 and 2016. Our 2016 study included newly discovered populations and added to our genetic study. We incorporated these new populations into species distribution niche model (SDM) and projected these onto maps of the region. We developed population matrix models based on observed demographic data to model population change and predict the species vulnerability to extinction by undertaking population viability analysis (PVA). We investigated the potential conservation value of reintroduced planted populations within the species potential suitable habitat. We found that the population studied in 2008 had grown in size due to seedling regeneration but had declined in the number of reproductively mature plants, and we were able to estimate that the species reproduces and dies after approximately 70 years. Our models suggest that if the habitat where it resides continues to be protected the species is unlikely to go extinct due to inherent population decline and that it will likely experience significant population growth after approximately 80 years due to the reproductive and life cycle attributes of the species. The newly discovered populations contain more genetic diversity than the first discovered southern population which is genetically depauperate. The species appears to demonstrate a pattern of dispersal leading to isolated founder plants which may eventually lead to population development depending on local establishment opportunities. The conservation efforts currently put in place including the reintroduction of plants within the species potential suitable habitat if maintained are thought likely to enable the species to sustain itself but it remains vulnerable to anthropogenic impacts

    Persistence, size, trends and productivity in populations of two Critically Endangered Indonesian cockatoos

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    The aim of this thesis was to understand patterns of persistence, size, trends and productivity in populations of two Critically Endangered and heavily traded Indonesian cockatoos: the Yellow-crested Cockatoo Cacatua sulphurea and Citron-crested Cockatoo Cacatua citrinocristata. The Yellow-crested Cockatoo was formerly common and widespread on many islands of Wallacea. Its former subspecies on Sumba, the Citron-crested Cockatoo, was recently elevated to species level. After dramatic declines information on the remnant populations of both species is essential to guide future conservation management. A challenge with species that have disappeared from most of their range is to identify correlates of local persistence. The Yellowcrested Cockatoo and Citron-crested Cockatoo have undergone catastrophic declines due to habitat loss and especially trapping. The former is now extinct in much of its range across Indonesia while the latter has lost substantial numbers and some of its old sites on Sumba. Of 144 sites supporting cockatoos in 1950 only 76 did so in 2015. I compared socio-ecological conditions between the occupied and unoccupied sites, using 'random forests'. Tree cover, sparse human densities and low road densities promoted cockatoo survival but site-specific conditions (e.g. sacred groves, NGO activities) were also important. These local influences offer exciting possibilities for low-cost conservation prescriptions tailored to individual sites. One of the few Yellow-crested Cockatoo populations still numbering >100 individuals survives on Komodo Island. Distance sampling was combined with density surface modelling (DSM) to predict local densities and estimate total population size for this island. The population estimate of 1,113 (95% CI: 587–2,109) individuals on Komodo was considerably larger than previous conservative estimates. Coincidence between the DSM and a set of independent cockatoo observations was high (93%). Standardised annual counts by national park staff showed increases in cockatoo records from <400 in 2011 to ~650 in 2017. Taken together, the results indicate that Komodo National Park, alongside and indeed because of preserving its iconic Komodo Dragons Varanus komodoensis, is succeeding in protecting a significant population of Indonesia's rarest cockatoo species. This study's findings highlight the potential of DSM for locating abundance hotspots and estimating global population size in a range of threatened taxa. Although the importance of long-term monitoring is widely recognised, very few tropical bird species have been monitored over the span of 25 years. A multi-species distance sampling survey from 1992 was replicated in 2017, and present data on five parrot species and a hornbill, with three threatened island endemics, Citron-crested Cockatoo Cacatua citrinocristata (CR), Sumba Eclectus Eclectus cornelia (EN) and Sumba Hornbill Rhyticeros everetti (EN), two restricted-range species, Great-billed Parrot Tanygnathus megalorynchos and Marigold Lorikeet Trichoglossus capistratus, and one Wallacean-Papuan species, Red-cheeked Parrot Geoffroyus geoffroyi. Densities of the three large parrots and the hornbill in 2017 were similar to 1992 but densities of the smaller Red-cheeked Parrot and Marigold Lorikeet declined significantly in the same time span. Quantity of forest on Sumba is assessed for both years, presence data and local density estimates to gauge island-wide population sizes. The Marigold Lorikeet may need a re-assessment of its global Red List status. The uncertainty in trends for the threatened cockatoo, eclectus and hornbill is of concern as they show no definite sign of sustainable recovery from the extensive trapping of past decades. Knowledge of breeding success and its limiting factors is crucial in assessing species' conservation needs. As hole-nesters, parrots are particularly influenced by the availability of suitable cavities and low breeding output. On Sumba, the Citron-crested Cockatoo has to compete with an unusually rich hole-nesting bird community affected by forest loss. Ninety-five nesting cavities of cockatoos were monitored including competitors and potential nest-predators, over one to four breeding seasons, using a combination of camera-traps, direct checks on nest contents, and observations from the ground. Competition for suitable cavities was intense among three large parrot species, two owls and a hornbill. The Endangered Sumba Hornbill dominated observed direct confrontations and was the most frequent visitor to active parrot nests, suggesting a further role as a potential nest-predator. Cockatoos prospected many cavities but rarely then attempted to nest. At the few cavities where cockatoos did breed, predation pressure was likely low, and observed success rate high (10 successful of 15 nests). Intense competition for cavities suggests a shortage of suitable nest-sites, the need to preserve old hole-bearing trees and a role for nestboxes. Both studied cockatoo species would benefit from targeted local awareness-raising and law enforcement, with the whole endeavour backed up by longer-term forest restoration. The recent split of the Citron-crested Cockatoo leaves the resultant two species at higher risk of extinction than when they were assessed combined. The population on Sumba remains under pressure from illegal trapping, habitat loss, nest site competition and appears to have low productivity. Only two of the six Yellow-crested Cockatoo subspecies retain wild populations > 300 individuals but for each subspecies recovery is still possible, if conservation management tailored to each location is implemented, including public awareness programmes, provision of nestboxes, logistical and capacity building support, habitat protection and law enforcement
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