Best practice for minimising unmanned aerial vehicle disturbance to wildlife in biological field research.

The use of unmanned aerial vehicles (UAVs), colloquially referred to as 'drones', for biological field research is increasing [1-3]. Small, civilian UAVs are providing a viable, economical tool for ecology researchers and environmental managers. UAVs are particularly useful for wildlife observation and monitoring as they can produce systematic data of high spatial and temporal resolution [4]. However, this new technology could also have undesirable and unforeseen impacts on wildlife, the risks of which we currently have little understanding [5-7]. There is a need for a code of best practice in the use of UAVs to mitigate or alleviate these risks, which we begin to develop here.

Precision wildlife monitoring using unmanned aerial vehicles.

Unmanned aerial vehicles (UAVs) represent a new frontier in environmental research. Their use has the potential to revolutionise the field if they prove capable of improving data quality or the ease with which data are collected beyond traditional methods. We apply UAV technology to wildlife monitoring in tropical and polar environments and demonstrate that UAV-derived counts of colony nesting birds are an order of magnitude more precise than traditional ground counts. The increased count precision afforded by UAVs, along with their ability to survey hard-to-reach populations and places, will likely drive many wildlife monitoring projects that rely on population counts to transition from traditional methods to UAV technology. Careful consideration will be required to ensure the coherence of historic data sets with new UAV-derived data and we propose a method for determining the number of duplicated (concurrent UAV and ground counts) sampling points needed to achieve data compatibility.

Prevalence and composition of marine debris in Brown Booby (Sula leucogaster) nests at Ashmore Reef.

Anthropogenic debris is ubiquitous in the marine environment and has been reported to negatively impact hundreds of species globally. Seabirds are particularly at risk from entanglement in debris due to their habit of collecting food and, in many cases, nesting material off the ocean's surface. We compared the prevalence and composition of debris in nests and along the beach at two Brown Booby (Sula leucogaster) colonies on Ashmore Reef, Timor Sea, a remote area known to contain high densities of debris transported by ocean currents. The proportion of nests with debris varied across islands (range 3-31%), likely in response to the availability of natural nesting materials. Boobies exhibited a preference for debris colour (white and black), but not type. The ephemeral nature of Brown Booby nests on Ashmore Reef may limit their utility as indicators of marine pollution, however monitoring is recommended in light of increasing demand for plastic products.