We investigated the use of inexpensive aerial bridges (rope canopy bridges) above roads and a highway by arboreal mammals in the Wet Tropics of Queensland, Australia. Three rope bridge designs were trialed, including a single rope, ladder-like bridges and tunnel-shaped bridges. Nine mammal species were recorded using canopy bridges, including five species or subspecies endemic to the Wet Tropics and three species listed as rare under State nature conservation legislation. Most of these species suffer severely from either the fragmentation or mortality impacts caused by roads. Over 50 crossings above a 15-m-wide tourist road were observed on an elevated ladder-like bridge. Longer (~40 m) rope bridges were used on several occasions by four species. Our observations suggest that canopy bridges can assist rare arboreal mammals to cross roads in the Wet Tropics, thereby reducing both the risk of road-kill and the potential for subpopulation isolation. Further research is required to ascertain the level of benefit afforded by canopy bridges for arboreal mammal populations. It is likely that rope canopy bridges will have broad application for a range of arboreal mammal species.

The Intergovernmental Panel on Climate Change has identified Australia as among the developed nations most at risk from climate change effects. Key tourism icon destinations and the tourism sector generally have been identified as being particularly at risk. This paper reports on an interdisciplinary, multi-case study approach to assess tourism stakeholders' knowledge of, and approaches to climate change adaptation, and to explore the potential for building a self assessment toolkit that can be exported to other tourism destinations. This study examined existing knowledge on anticipated biophysical changes and, through primary research (stakeholder interviews and social learning workshops), gauged the expected adaptive approaches of destination communities and the tourism sector to these changes for 2020, 2050 and 2070. The facilitated workshops generated a common set of adaptation strategies across a diverse set of tourist destinations. A key finding from the workshops is that the tourism sector is not yet ready to invest in climate change adaptation because of the perceived uncertainties. Ongoing leadership for such measures were seen to rest with the public sector, especially local authorities.Whether such assessments can be self generated, or require specialist facilitation, remains open to debate.

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The general objective is the development of efficient techniques for preliminary design of trajectory arcs in nonlinear autonomous dynamic systems in which the desired solution is subject to algebraic interior and/or exterior constraints. For application to the n-body problem, trajectories must satisfy specific requirements, e.g., periodicity in terms of the states, interior or boundary constraints, and specified coverage. Thus, a strategy is formulated in a sequence of increasingly complex steps: 1) a trajectory is first modeled as a series of arcs (analytical or numerical) and general trajectory characteristics and timing requirements are established; 2) the specific constraints and associated partials are formulated; 3) a corrections process ensures position and velocity continuity while satisfying the constraints; and finally, 4) the solution is transitioned to a full model employing ephemerides. Though the examples pertain to spacecraft mission design, the methodology is generally applicable to autonomous systems subject to algebraic constraints. For spacecraft mission design applications, an immediate advantage of this approach, particularly for the identification of periodic orbits, is that the startup solution need not exhibit any symmetry to achieve the objectives.

This paper addresses the computation of the required trajectory correction maneuvers (TCM) for a halo orbit space mission to compensate for the launch velocity errors introduced by inaccuracies of the launch vehicle. By combining dynamical systems theory with optimal control techniques, we are able to provide a compelling portrait of the complex landscape of the trajectory design space. This approach enables automation of the analysis to perform parametric studies that simply were not available to mission designers a few years ago, such as how the magnitude of the errors and the timing of the first trajectory correction maneuver affects the correction ~ V. The impetus for combining dynamical systems theory and optimal control in this problem arises from design issues for the Genesis Discovery mission being developed for NASA by the Jet Propulsion Laboratory.

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Roads and powerline corridors destroy canopy connectivity in the rainforest of north-east Australia. We tested the hypotheses that linear barriers affect (a) the alignment of home ranges, (b) use of habitat either side of linear barriers, and (c) the crossing of them by the strictly arboreal lemuroid ringtail possum (Hemibelideus lemuroides), which is known to be vulnerable to habitat fragmentation. Radio-tracking and a translocation experiment were conducted at a narrow 7-m-wide road and an 80-m-wide powerline. Homes ranges of lemuroid ringtails ranged from 0.15 to 1.67 ha (minimum convex polygon) and were aligned with the road but not powerline corridors. When lemuroid ringtails were experimentally translocated, wider canopy clearings over roads reduced their capacity to return to their original home range, and the powerline corridor was a nearly insurmountable barrier. No possums were observed crossing roads or the powerline corridor at ground level or residing in the intervening matrix, indicating that loss of canopy connectivity has a negative impact on their movements.

Lumholtz's Tree-kangaroo Dendrolagus lumholtzi is endemic to the rainforests of north Queensland, Australia. Most records of D. lumholtzi are from upland forests on the Atherton Tablelands, an area extensively cleared for agriculture. In 1997, residents of the Tablelands formed the Tree Kangaroo and Mammal Group Inc. (TKMG) with the aim of promoting the conservation of the species. The first project of TKMG was an intensive community-based survey of the distribution of D. lumholtzi. Residents of all postal districts encompassing areas of upland rainforest within the range of D. lumholtzi were sent a written questionnaire seeking details of tree-kangaroo sightings. The Malanda postal district was surveyed in 1998 while all other postal districts were surveyed in 1999. In total, 10 122 questionairres were distributed in the survey. "Nearly 800 responses were received to the survey, providing 2 368 sighting records of D. lumholtzi. Of these, 367 records were of dead tree-kangaroos, mostly road-kills." The survey has provided a much more comprehensive account of the distribution of the species than was previously available. Most records of D. lumholtzi obtained in the survey were from upland forests between Atherton and Ravenshoe, particularly remnant forests in the central and western Tablelands. Although the survey methodology is biased towards areas frequented by humans, these patterns are consistent with independent surveys. The conservation of D. lumholtzi on the Tablelands would benefit from the protection of remnant forests, the restoration of habitat and a reduction in the incidence of road-kills and dog attacks on tree-kangaroos.