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In an elevational gradient, the mountain top generally presents a reduced species diversity. However, it is there where we often find microendemic and quite often still undescribed species. That prediction is very common in underexplored Neotropical mountains, like those of the Caparaó National Park – a protected area that includes the highest peak of the Atlantic Forest, a megadiverse domain. Up in its top, we found a dwarf frog of the genus Physalaemus (Anura, Leptodactylidae, Leiuperinae), belonging to the P. signifer clade. After an integrative (morphological, bioacoustical, and genetic) analysis, we were able to describe it as a new species and found it to be sister to P. maculiventris. Due to its very restricted distribution at a site with extreme environmental conditions (which includes fires and frosts) and current instability in national environmental policy, we suggest this to be classified as an endangered species. A brief description of its natural history and the description of the species itself will now enable its proper conservation status categorization and the future planning for conservation actions.

Animals that present migration restrictions are especially interesting to study isolation effects in the context of island biogeography theory. Among these effects, behavioral traits are one of the least studied subjects. The treefrog Boana albomarginata presents gigantism in some Atlantic islands and, therefore, examining its advertisement calls may be an opportunity to test the Island Rule with a behavioral trait. Hence, we compared calls, body and tympanum sizes of populations of this species in Brazilian islands and mainland sites. We tested if call frequencies of island individuals differed from mainland ones, also considering the influence of body size and its relationship with tympanum diameter. One of the island population had larger body size and lower call frequencies than any other populations. We suggest that to be a result of directional selection. We also observed lack of correlation between body size and advertisement call frequencies in some populations, implying that males and females cannot use calls as a proxy of the calling male's size, which may indicate a rare case of relaxed selection. Therefore, this is the first evidence of relaxed selection in animal communication, as a consequence of recent insularity.

Abstract The use of individual phenotypic features as non-invasive marks through photo-identification (photo-ID) has many advantages for individual-based field studies. However, since error rates vary between species, matching techniques, and image qualities, it is important to assess error rates to evaluate the reliability of photo-ID. We tested the performance of this method in the Pacific Horned Frog, Ceratophrys stolzmanni, a threatened anuran with a variable dorsal coloration. We compared the effectiveness of visual (i.e. human recognition) versus software-assisted recognition techniques (Wild-ID and APHIS), and assessed the potential applicability of these techniques to identify post-metamorphic individuals (froglets). The three techniques differed in their performance. The visual technique was the only one to produce type I errors between pairs of images (i.e. matching images which are not true matching pairs), however it also produced fewer type II errors (i.e. not identifying true matching pairs of images) than the software-assisted techniques. For froglets, we found that similarity scores calculated by photo-ID software did not differ significantly between groups of froglets and older individuals, supporting the idea that colour patterns in this species remain stable after metamorphosis. The lack of type I errors and the substantial reduction in required time achieved through the use of software, make software-assisted techniques (particularly Wild-ID) a valid and convenient matching technique for C. stolzmanni. We propose that photo-ID can also be applied to froglets of this species, since the pattern at this stage appears to be as variable as in adults and maintained through life.

The Outlook article 'Expanding the reach of science' (Nature 562, S10-S11; 2018) cited the wrong value for the number of STEM teachers in Accra who have been trained by The Exploratory. It should have been 70, not 700. Support for African clinician scientists As members of Africa's next generation of scientists, we agree that there is a need to build the capacity of African institutions to train skilled researchers and scholars (see go.nature. com/2araify). To this end, we recently founded the South African Clinician Scientists Society (www.sacss.co.za). By creating a collegial environment for emerging specialists, we hope this, and similar societies, will contribute to attracting and retaining African scientists and easing their scientific journey (see Nature 562, S58-S61; 2018). Researchers who return from training abroad to a supportive and enabling environment make the transition into successful independent scientists faster than do isolated researchers. So, the society uses three strategies to nurture talented professionals, centred on relationships. First, it identifies suitable mentors. Second, the society develops research networks. Third, it aims to create multidisciplinary research units that provide administrative and research support.