Scientific research and data is important in today’s knowledge society and to help guide informed actions and decisions. Below is a list and download links of EWB researchers’ peer-reviewed papers published in scientific journals, within the last few months. To read or download more, please see our Publications page and survey reports on Aerial Survey page!
Elephants: Understanding the Drivers of Mortality in African Savannah Elephants, published in Ecological Applications, May 2020. Populations of African savannah elephants (Loxodonta africana ) have been declining due to poaching, human–elephant conflict, and habitat loss. Understanding the causes of these declines could aid in stabilizing elephant populations. https://doi.org/10.1002/eap.2131
Mapping: Automated Inundation Mapping Over Large Areas Using Landsat Data and Google Earth Engine, published in Remote Sensing, April 2020. Accurate inundation maps for flooded wetlands and rivers are a critical resource for their management and conservation. Inundation classification in the Okavango Delta is complex owing to the spectral overlap between inundated areas covered with aquatic vegetation and dryland vegetation classes on satellite imagery, and classifications have predominately been implemented on broad spatial resolution imagery. We present the longest time series to date (1990–2019) of inundation maps for the peak flood season at a high spatial resolution (30 m) for the Okavango Delta. Open Access: https://doi.org/10.3390/rs12081348
Counting Waterbirds: Counting Mixed Breeding Aggregations of Species Using Drones: Lessons from Waterbirds on Semi-Automation, published in Remote Sensing, April 2020: Using drones to count wildlife saves time and resources and allows access to difficult or dangerous areas. We collected drone imagery of breeding waterbirds at colonies in the Okavango Delta (Botswana) and Lowbidgee floodplain (Australia). We developed a semi-automated counting method, using machine learning, and compared effectiveness of freeware and payware in identifying and counting waterbird species (targets) in the Okavango Delta. We tested transferability to the Australian breeding colony. Open Access: https://doi.org/10.3390/rs12071185
Hippo: Drone-based effective counting and aging of hippopotamus (Hippopotamus amphibius) in the Okavango Delta in Botswana, published in Plus One. Accurately estimating hippopotamus (Hippopotamus amphibius) numbers is difficult due to their aggressive nature, amphibious lifestyle, and habit of diving and surfacing. Traditionally, hippos are counted using aerial surveys and land/boat surveys. We compared estimates of numbers of hippos in a lagoon in the Okavango Delta, counted from land to counts from video taken from a DJI Phantom 4TM drone, testing for effectiveness at three heights (40 m, 80 m, and 120 m) and four times of day (early morning, late morning, early afternoon, and late afternoon). In addition, we determined effectiveness for differentiating age classes (juvenile, subadult, and adult), based on visual assessment and measurements from drone images, at different times and heights. Open access: https://doi.org/10.1371/journal.pone.0219652
Giraffe: Updated geographic range maps for Giraffe, Giraffa spp., throughout sub-Saharan Africa, and implications of distributions for conservation, published in Mammal Review, Vol.49, Iss 4. Giraffe populations have declined in abundance by almost 40% over the last three decades, and the geographic ranges of the species (previously believed to be one, now defined as four species) have been significantly reduced or altered. With substantial changes in land uses, loss of habitat, declining abundance, translocations, and data gaps, the existing geographic range maps for giraffe need to be updated. Open access: https://onlinelibrary.wiley.com/doi/epdf/10.1111/mam.12165