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Allosuckling, the suckling of milk from a non-biological mother, occurs in some species of mammals. Allosuckling has not been quantified in baleen whale calves; therefore, we examine allosuckling in southern right whales (SRWs; Eubalaena australis) off Australia. SRWs are listed as Endangered under the Australian Environment Protection and Biodiversity Conservation Act as their numbers remain below the estimated historical abundance. On a small aggregation area, where there were three mother–calf pairs present, we aimed to quantify the proportion of time that calves allosuckled relative to the time spent filial suckling. To achieve this, we conducted unmanned aerial vehicle focal follows on mother–calf pairs and video recorded all interactions among pairs (n = 22 interactions, 3 h total observation time). During interactions, allosuckling occurred in seven interactions, and filial nursing occurred in 11 interactions. One of the calves performed allosuckling, and it was the largest calf with the largest mother. The calf allosuckled from both of the non-biological mothers present. The average proportion of time allosuckling per interaction was 4% (95% CI = ± 0.01, range = 0–0.25), whilst filial nursing for the same calf was 8% (95% CI = ± 0.02, range = 0–0.37). It is important to understand the frequency of allosuckling, and to quantify the energetic benefits for allosuckling calves and the energetic cost incurred by targeted non-biological mothers. This is particularly pertinent for capital breeders who do not replenish lost energy reserves until they migrate to their feeding grounds. [ABSTRACT FROM AUTHOR]

Drone use has increased in the last decade prompting management efforts to regulate flights near vulnerable wildlife; however, these efforts are hindered by a lack of data characterising drone‐induced wildlife disturbance. Many shorebird populations are rapidly declining and efforts to survey them can be hampered by the inaccessibility of their habitat. Drone surveys might overcome this barrier, although there is a risk that increased drone use near shorebirds may cause disturbance and exacerbate declines. We characterise drone‐induced disturbance for mixed‐species shorebird flocks to inform the management of drones near shorebirds.We conducted 240 drone approaches of mixed‐species flocks containing roosting non‐breeding shorebirds in Moreton Bay, eastern Australia. We performed approaches horizontally at varying vertical distances and recorded metrics characterising the drone, flock and environment. This enabled us to estimate the factors influencing disturbance as well as the distance of an approaching drone at which the flock is likely to take flight.We determined the drone‐induced flight initiation distance for 12 species of waterbird, including seven shorebird species. We could not approach Eastern Curlew Numenius madagascariensis at any vertical distance below the recreational drone limit of 120 m without inducing flight; however, for all other species, there was less than 20% probability that they would take flight when approached by a drone at vertical distances above 60 m. We do not recommend approaches below 30 m. We also found that flight initiation of mixed‐species flocks is largely dictated by the most sensitive species present, and that disturbance generally increases with approach velocity, drone noise/size, decreasing distance, and if the drone is obscured by trees.Policy Implications. We conclude that (i) drone use needs to be carefully regulated to ensure roosting shorebird flocks are not approached within distances that will disturb the most sensitive species likely to be present, (ii) researchers contemplating drone surveys need to carefully evaluate the risk of disturbance, especially where there are mixed‐species flocks, and (iii) that alternatives to drone surveys should be sought wherever disturbance data for the species potentially encountered are unavailable. [ABSTRACT FROM AUTHOR]

Bird damage to commercial crops is a significant problem across the globe, especially for high value crops like wine grapes. Various bird control methods have been developed in the past to reduce bird damage. After a brief review of the current bird damage control strategies, we found the most effective methods, such as netting and hiring a human scarer, rely on intensive manual labour, as well as fragile and costly infrastructure. Whereas the cheaper methods, such as using alarm calls and predator models, are effective for no more than two weeks before the birds habituate to them. We are proposing a novel Unmanned Aerial Vehicle (UAV, more commonly referred to as drone) system incorporating bird psychology for efficient bird damage control. The UAV is equipped with a loud speaker broadcasting distress calls, as well as a crow taxidermy installed on the undercarriage that appears as captured prey. This special UAV configuration is designed to engage birds' well-established abilities to learn to recognise and avoid novel predators, thus providing the benefit that a long-term fear response towards the UAV can be expected. The initial trials were carried out in vineyards around south-eastern Australia. Results indicated the UAV can deter large pest birds such as ravens and cockatoos in a 50-m radius centred on the UAV for an extended period of time. The UAV can also effectively deter small pest birds such as silvereyes for brief time periods after exposure to the UAV. It is also evident from the results that while one UAV is sufficient to protect vineyards smaller than 25 ha, multiple UAVs are needed to protect a large vineyard effectively. • UAV incorporating bird psychology is an effective short-term bird deterring strategy. • The minimum radius of influence of the UAV is 50 m. • Effect of UAV on Silvereyes (Zosterops lateralis) lasts at least 15 min. • A single UAV can protect one vineyard up to 25 ha. • Multiple UAVs are necessary for vineyards larger than 25 ha. [ABSTRACT FROM AUTHOR]

Background: Recent conflicts in the Middle East have seen rapid developments in the use of unmanned aerial vehicles (UAV). The Australian Government plans to acquire a number of UAVs to perform a range of operations. Purpose: To determine whether UAV operators are exposed to greater or special risks to their mental health than other combatants. Method: A non-systematic, narrative literature search was undertaken into the mental health of UAV operators. Results: The adverse effect of occupational stressors, such as long working hours, on well-being and mental health outcomes emerged strongly. Prevalence rates of clinically significant symptoms of PTSD (Post Traumatic Stress Disorder) for UAV operators were found to be low, ranging between 2 - 5%. Conclusion: These outcomes were consistent with occupational stressors found in the military context and previous findings on other military personnel with low combat exposure. This review is a first step towards establishing an evidence base to inform the management of mental health problems in UAV operators. [ABSTRACT FROM AUTHOR]

Changes to coral reef landscapes are driven by regional processes that are unique to particular localities, yet much of our global knowledge about how landscape changes manifest in coral reef environments is generalised from work undertaken on the Great Barrier Reef. We compare observations of 45 years of change on sand cays and mangroves associated with low wooded islands in Australia and Indonesia. We draw on field observations from ground referencing campaigns, alongside remote sensing technology, including satellite images and unmanned aerial vehicle campaigns. Four low wooded island sites are compared: two in the Great Barrier Reef (GBR), Australia (Nymph Island and Two Isles) and two in the Spermonde Archipelago, Indonesia (Sabangko and Tanakeke Island). The Spermonde and GBR sites can be distinguished in relation to the process regimes that entrain, distribute and deposit sediments on the reef surface thereby providing a substrate for further mangrove colonisation, particularly the presence or absence of cyclones as a key determinant of sediment transport. The influence of human populations inhabiting these sites is also an important control on their geomorphology. In the Spermonde Archipelago, local communities have altered sand cays through the development of infrastructure and converted mangroves to shrimp farms, while sand cays and mangroves have remained largely unaltered by humans on the GBR. This comparative evaluation of changes to sand cays and mangrove forest across low wooded islands emphasises the importance of considering changes within the context of their local geographic setting, inclusive of natural environmental and anthropogenic drivers of change. • We compare sand cay and mangroves changes on Australian and Indonesian reef islands. • Changes are observed for the GBR, Australia and Spermonde archipelago, Indonesia. • Spermonde and GBR sites have distinctive the sedimentary and anthropogenic dynamics. • Changes on reef islands depend on local environmental and anthropogenic influences. [ABSTRACT FROM AUTHOR]

Mangrove ecosystems are targeted for many conservation and rehabilitation efforts due to their ability to store large amounts of carbon in their living biomass and soil. Traditional methods to monitor above-ground biomass (AGB) rely on on-ground measurements, which are expensive, labour intensive and cover small spatial scales. Structure from Motion and Multi-View Stereo reconstructions from Unmanned Aerial Vehicles imagery (UAV-SfM) have the potential to increase fieldwork efficiency by providing a greater amount of spatial information in less time. However, there is still a need to assess the ability of UAV-SfM to retrieve structural information of mangrove forests, which could pose challenges in areas of high forest complexity and density. In this study we successfully used UAV-SfM data to estimate height, canopy diameter and AGB of natural and rehabilitated mangrove forests across two regions of the southeastern coast of Australia. We used a variable window filter algorithm to detect trees with an 80% detection rate when considering the top canopy. Individual tree canopy segmentation was performed using a marker-controlled watershed segmentation with two sets of constraining markers: treetops and a minimum height below which a pixel is not considered part of a tree. Direct comparison with on-ground measurements at the regional level showed no significant difference in tree height and AGB medians when only top canopy was considered. Similarly, median canopy diameters were not significantly different in natural areas of both regions, but significant differences were found in rehabilitated areas. UAV-SfM estimates of AGB were on average 15% lower in natural areas and 10% higher in rehabilitated areas when compared to on-ground measurements and followed a strong linear relationship close to the ideal one-to-one relationship. Additionally, we performed a cost-benefit analysis of the two methodologies. UAV-SfM methods can save almost AU$ 50,000 per ha when compared to on-ground measurements and become cost-effective (based on total costs) after just 15 days of surveys. The methods described in this study open the possibility for easily repeatable, low-cost UAV-SfM surveys for local managers by providing a faster, more cost-effective approach for monitoring mangrove forests over larger areas than traditional on-ground surveys while maintaining forest inventory data accuracy in both natural and rehabilitated mangrove forests. • UAV imagery can be used to assess AGB of natural and rehabilitated mangrove forests. • Mangrove tree height and canopy diameter accurately estimated • UAVs are more cost-effective than on-ground surveys (AU$ 50,000 savings per ha). [ABSTRACT FROM AUTHOR]

Narrabeen-Collaroy Beach, located on the Northern Beaches of Sydney along the Pacific coast of southeast Australia, is one of the longest continuously monitored beaches in the world. This paper provides an overview of the evolution and international scientific impact of this long-term beach monitoring program, from its humble beginnings over 40 years ago using the rod and tape measure Emery field survey method; to today, where the application of remote sensing data collection including drones, satellites and crowd-sourced smartphone images, are now core aspects of this continuing and much expanded monitoring effort. Commenced in 1976, surveying at this beach for the first 30 years focused on in-situ methods, whereby the growing database of monthly beach profile surveys informed the coastal science community about fundamental processes such as beach state evolution and the role of cross-shore and alongshore sediment transport in embayment morphodynamics. In the mid-2000s, continuous (hourly) video-based monitoring was the first application of routine remote sensing at the site, providing much greater spatial and temporal resolution over the traditional monthly surveys. This implementation of video as the first of a now rapidly expanding range of remote sensing tools and techniques also facilitated much wider access by the international research community to the continuing data collection program at Narrabeen-Collaroy. In the past decade the video-based data streams have formed the basis of deeper understanding into storm to multi-year response of the shoreline to changing wave conditions and also contributed to progress in the understanding of estuary entrance dynamics. More recently, 'opportunistic' remote sensing platforms such as surf cameras and smartphones have also been used for image-based shoreline data collection. Commencing in 2011, a significant new focus for the Narrabeen-Collaroy monitoring program shifted to include airborne lidar (and later Unmanned Aerial Vehicles (UAVs)), in an enhanced effort to quantify the morphological impacts of individual storm events, understand key drivers of erosion, and the placing of these observations within their broader regional context. A fixed continuous scanning lidar installed in 2014 again improved the spatial and temporal resolution of the remote-sensed data collection, providing new insight into swash dynamics and the often-overlooked processes of post-storm beach recovery. The use of satellite data that is now readily available to all coastal researchers via Google Earth Engine continues to expand the routine data collection program and provide key insight into multi-decadal shoreline variability. As new and expanding remote sensing technologies continue to emerge, a key lesson from the long-term monitoring at Narrabeen-Collaroy is the importance of a regular re-evaluation of what data is most needed to progress the science. [ABSTRACT FROM AUTHOR]