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Assessing the availability of aerially delivered baits to feral cats through rainforest canopy using unmanned aircraft

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Abstract

At least eight threatened wildlife species are at direct risk from predation by cats (Felis catus) on Christmas Island (Department of the Environment 2014). A range of strategies are now being used to manage cats across the island, inclusive of responsible ownership methods being mandated for owned cats and lethal control methods used to remove feral cats inhabiting areas outside the township area. Unmanned aircraft were used to provide a cost-effective solution to determine whether aerial baiting could be undertaken successfully through the tropical rainforest canopy. A video supporting this manuscript can be accessed at https://www.youtube.com/watch?v=w1VTOeNljXU&feature=youtu.be
... Deployment of baits from an aircraft was not considered feasible on CI at the commencement of this campaign due to the removal of baits by the abundant land crabs. However, targeted aerial baiting into discrete diffi cult to access areas is now being contemplated for late in the dry season when land crabs are less active (Johnston, et al., 2016). Preliminary baiting exercises on the island where baits were placed on the ground, highlighted the potential problem of non-target species removing ground-laid baits. ...
Conference Paper
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... Protected areas often face human-wildlife conflicts in populated areas bordering their limits [74]. Some studies described the use of drones in various management tasks, such as moving elephants out of human settlements [75], mapping wildlife damage on crops to calculate compensation costs [76] or dropping fake baits targeting feral species [77]. Drones constitute an attainable low-cost alternative to assess and reduce the risk that hazardous infrastructures [78,79] or mechanical harvesting [80,81] pose to wildlife. ...
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Park managers call for cost-effective and innovative solutions to handle a wide variety of environmental problems that threaten biodiversity in protected areas. Recently, drones have been called upon to revolutionize conservation and hold great potential to evolve and raise better-informed decisions to assist management. Despite great expectations, the benefits that drones could bring to foster effectiveness remain fundamentally unexplored. To address this gap, we performed a literature review about the use of drones in conservation. We selected a total of 256 studies, of which 99 were carried out in protected areas. We classified the studies in five distinct areas of applications: “wildlife monitoring and management”; “ecosystem monitoring”; “law enforcement”; “ecotourism”; and “environmental management and disaster response”. We also identified specific gaps and challenges that would allow for the expansion of critical research or monitoring. Our results support the evidence that drones hold merits to serve conservation actions and reinforce effective management, but multidisciplinary research must resolve the operational and analytical shortcomings that undermine the prospects for drones integration in protected areas.
... These threats have already caused several extinctions on the island (Wyatt et al., 2008;Lunney et al., 2011), and the loss of the Christmas Island pipistrelle was particularly frustrating, given the rescue effort . To avoid further extinctions, threatened species on Christmas Island now receive priority attention with management acting on the conservation of individual species, the restoration of degraded land and the removal of damaging invasive species, such as yellow crazy ants (Abbott et al., 2014) and feral cats (Johnston et al., 2016). ...
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Poster
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Land managers of conservation estate can make better decisions when they have access to up- to-date aerial imagery or other data sourced in conjunction with support from the local air charter operator. However, the acquisition of these resources can prove expensive at remote sites. This is specifically the case with Christmas Island which is located 2600 kilometres north-west of Perth and has no local light aircraft operator. Instead, we used two unmanned aircraft to collect the required data across multiple mission objectives in a timely and cost- effective manner. The primary objective was to assess whether aerial baiting would be an effective method of delivering baits to feral cats given the dense canopy. Baits were dropped over sites comprising representative vegetation communities with ground crews then relocating these baits and determining the proportion that were accessible to feral cats. Secondly, high resolution aerial mapping of these sites was then undertaken with other mapping missions also undertaken over other park infrastructure or revegetation sites. Digital elevation models were then prepared from this imagery. A thermal video camera was used to evaluate the viability of conducting fauna counts of threatened species such as Abbott’s Booby and CI Flying fox. Examples of the outcomes of this work will be shown at the conference.
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Since the turn of the century, emerging unmanned aircraft systems (UAS) have found increasingly diverse applications in wildlife science as convenient, very high-resolution remote sensing devices. Achieved or conceptualized applications include optical surveying and observation of animals, autonomous wildlife telemetry tracking, and habitat research and monitoring. As the technology continues to progress and interest from the wildlife science community grows, there may yet be much untapped potential for UAS to contribute to the discipline. We present a review of the published primary literature on the application of UAS in wildlife science and related fields. This is followed by a systematic review of the broader wildlife science literature published since the turn of the century to assess where UAS are likely to make important contributions going forward based on the trends that have emerged thus far. UAS, in particular small lightweight models, are generally well suited for collecting data at an intermediate spatial scale between what is easily coverable on the ground and what is economically coverable with conventional aircraft. They are particularly useful for monitoring wildlife and habitats in places that are difficult to access or navigate from the ground, as well as approaching sensitive or aggressive species.
A collaborative framework for cat control/eradication on an inhabited island: Christmas Island
  • D Algar
  • M Misso
  • J West
® bait distribution from an aircraft. Unpublished Report to Western Shield (p. 5). Department of Parks and Wildlife
  • D Algar
  • L Bell
  • S Cowen
  • M Onus
  • D Rasmussen