Visual lures increase camera-trap detection of the southern cassowary (Casuarius casuarius johnsonii)

Context: Monitoring is a key component in managing wildlife populations and is critical for revealing long-term population trends of endangered species. Cryptic or highly mobile species that occur in low densities and in remote terrain require the development of specific monitoring methods. The southern cassowary is an Australian endangered species that poses many challenges for conducting population surveys. Aims: The aims of the present study were to determine the effectiveness of camera traps in detecting cassowaries at a site, to determine whether visual lures increased detection rates, and to explore the potential of camera traps in population surveys. Methods: Coloured lures (mimicking large blue and red fruit) were placed in front of a set of camera traps and compared with controls (no lures) at 29 survey sites on the Daintree coast, northern Queensland, Australia. Key results: Camera traps with lures (1) detected more birds, (2) had a shorter detection latency, (3) had a marginally greater number of captures, (4) experienced a longer capture duration, (5) were more likely to have the cassowary stop in front of the camera, and (6) achieved a 95% probability of detecting cassowaries in 12 trap days, compared with 28 trap days without lures. Conclusions: An increase in the number of cassowaries detected, the reduction in camera latency times and the ability to identify the birds enables a more efficient approach to estimating population sizes over existing methods. This is the first published study to use visual lures to conduct camera trapping of birds.Implications: The use of camera traps with lures is a practical and cost-efficient technique for the rapid detection of cassowaries at a site and lends itself to studies of population structure, size and trends

A simple and effective ground-based tool for sampling tree flowers at height for subsequent nectar extraction

© 2020 British Ecological Society. Sampling nectar from forest canopies is logistically challenging to sample as it requires physical access to the canopy to a height greater than that can be achieved by hand. The most common solutions comprise the use of cherry pickers, cranes or tree climbers. These techniques are generally expensive, logistically complex, and often involve additional safety risks and specialized technicians to use the equipment/machinery. In addition, access is required up to the tree for cherry pickers and cranes, and tree climbers are often unable to reach the outermost branches. Here, we propose a simple approach based on a special, easy to assemble tool, to sample tree flowers for subsequent nectar extraction, to avoid climbing and cumbersome/expensive equipment. Conducting a study on nectar production of Eucalypt trees (Myrtaceae) in southwest Australia, we conceived a practical ground-based tool formed by an extendible pole with an adapted container at the end for covering the tree inflorescence with organza and plastic (polyethylene) bags. We experimented with the tool on dozens of trees of each of the co-occurring species Eucalyptus marginata and Corymbia calophylla, successfully completing the following operational manoeuvres: bagging the inflorescence with an organza bag prior to the nectar collection, then bagging the inflorescence and organza bags with plastic bags if necessary, and cutting the bagged inflorescences from the branch for subsequent nectar extraction. We present the instructions for assembling the tool and we detail the sequence for bagging and sampling flowers from canopy trees, including time-saving tips. This approach allows efficient sampling of tree flowers for subsequent nectar extraction. To effectively handle the tool while covering the inflorescence, the maximum sample collection height is approximately 10 m. Overall, the tool helps to address limitations related to sampling nectar from medium-height trees such as costs, risks and time factors. Beyond tree flowers, the tool can be used for sampling flowers of epiphytic and climbing plants, and it could also be used to test for autogamy in flowering trees