As human populations grow and transform undeveloped terrestrial and aquatic habitats, human–wildlife conflict inevitably increases. This is particularly problematic for large predators and the humans who live alongside them. Relatively little research has been conducted on alleviating adverse human encounters with one of the most significant predator species in Africa, the Nile crocodile Crocodylus niloticus. This short communication raises questions about some of the general statements made to explain the incidence of attacks by crocodiles. Some of the limitations of the data on such attacks are considered, with recommendations on what kinds of data are required. Data collection and analysis, and how they can inform more effective mitigation efforts, are discussed.

The conservation status of threatened taxa may be obfuscated by the detection of cryptic species complexes, in both vertebrate and invertebrate species. African dwarf crocodiles (Osteolaemus spp.) are hunted throughout their range but their conservation status is unknown. Few population assessments have been carried out and there has been a taxonomic revision of the number of species in the genus. The similar morphologies of Osteolaemus tetraspis and Osteolaemus osborni pose a challenge for conservation in Cameroon, where they are still managed as a single species. Nocturnal spotlight surveys were conducted in three regions during August–November 2010 and December 2011–February 2012 to provide population assessments of O. tetraspis and O. osborni and raise awareness of the two species in Cameroon. The mean encounter rates of O. tetraspis and O. osborni were 1.02 ± SD 1.34 (65 individuals in 39 surveys) and 0.61 ± SD 0.38 (three in four surveys) crocodiles per km, respectively. The O. tetraspis population comprised juveniles predominantly and had a male-biased sex ratio. The few O. osborni detected comprised both adults and juveniles. Both species are threatened in Cameroon, based on low encounter rates, young population structures and the threats of habitat loss and hunting pressure. This study provides distribution maps and serves as a baseline to quantify population trends and inform conservation strategies.

A major threat to river dolphins in Brazil is habitat loss and fragmentation as a result of the construction of hydroelectric dams. We examine the degree of overlap between the distributions of two river dolphin species (boto Inia geoffrensis and tucuxi Sotalia fluviatilis) and hydroelectric projects and provide an initial quantification of impacts. The locations of dams were overlaid onto a map of the known distributions of the dolphins. Two types of impacts were evaluated: population fragmentation and effects on prey. For each of these a binary score (for absence or presence) was assigned for each dam. The sum of all impact scores for each dam, in each of the three watersheds in which dolphins are found, including realized and potential impacts, was calculated as the impact index. Thirteen dams affect the distribution of I. geoffrensis (as could a further three dams under construction and seven planned), and three dams affect S. fluviatilis (as could three under construction and two planned). Overall, the impact index was higher for I. geoffrensis than for S. fluviatilis. The Araguaia–Tocantins and North Atlantic watersheds have higher impact index values than the Amazon watershed. Although some impacts of damming could not be considered in this study, our approach was a rapid initial risk assessment that provided an overall understanding of how river dolphins are and may be affected by hydroelectric projects in Brazil. Our method may be applicable to other freshwater cetaceans and species facing similar threats when information about impacts is incomplete.