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The critically endangered Brazilian Merganser Mergus octosetaceus is one of the rarest waterfowls in the world. Only three isolated populations remain in the Brazilian Cerrado, totaling less than 250 individuals. We evaluated the potential influence of small hydroelectric plants (SHPs) and Protected Areas (PAs) on the species’ conservation. We identified suitable areas by using recent presence records and environmental predictors, and overlapped it with the species dispersion zone and the SHP impact zone. Suitable areas for the species are limited to 4% of the geographic space (142,899 km2). Within the dispersion zone, we found 36 planned SHPs, which can impact 4.1% of the suitable area and 17.2% of the suitable area inside PAs. Our results expose the critical situation of the Brazilian Merganser, with few isolated suitable areas, high potential impacts for the three known populations, and a high proportion of suitable areas out of PAs. We highlight the need of considering SHPs impacts on the Brazilian Merganser in environmental impact assessment studies to reduce them. Furthermore, we appointed areas for search of new populations, and emphasize how urgent the implementation of effective conservation actions aiming to protect the remaining suitable habitats for the Brazilian Merganser is.

Background Prevalence of depression in chronic kidney disease (CKD) is higher than in the general population and predicts a higher mortality risk. The aim of this study is to investigate the occurrence of depressive symptoms among individuals with CKD in conservative treatment and renal replacement therapy (hemodialysis). Methods This is a cross-sectional study conducted at three health centers specialized in CKD care, in Fortaleza-Ceara-Brazil, between June and October 2015. Patients with confirmed diagnosis of CKD were included, in hemodialysis and conservative treatment, older than 18 years. We have applied forms about socio-demographic questionnaire, including questions regarding mental health and the Beck depression inventory. Results A total of 147 patients were interviewed, with mean age of 54 ± 16 years, and 61% were males. Regarding treatment, 65.3% were in hemodialysis and 34.6% in conservative treatment. Previous diagnosis of mental disturbance was reported by 12.9% of patients; 29 (19.7%) had follow-up with Psychologist or Psychiatrist; 61 (41.4%) demonstrated interest in having specialized treatment. According to Beck inventory score, 47 (31.9%) patients presented depressive symptoms, being 22 (14.9%) mild, 14 (9.5%) moderate and 7 (4.7%) severe symptoms. Among patients in hemodialysis, 30 (31.2%) had depressive symptoms, while among patients in conservative treatment, the frequency of depressive symptoms was 25.5% (p = 0.2). Conclusions There were a significant number of patients with CKD with depressive symptoms, both in conservative treatment and hemodialysis, with no significant difference between these two groups. Further studies are necessary to evaluate the repercussion of depression in clinical outcome, as well as the impact of preventive and treatment measures.

The degree of habitat specificity determines the distinctive ways that birds respond to land-use and climate change. Information on habitat-use, movement potential and sensitivity to human disturbance can promote reliable predictions on species response to spatial and temporal global changes. Here, we made an extensive review about habitat-use of 52 birds with distribution mainly in the Cerrado domain, a world hotspot with alarming climate change and land-use projections. We described habitat-use, classified habitats into three categories (grasslands, savannahs, and forests), inferred movement potential and sensitivity to human disturbance from records in anthropogenic matrices and identified knowledge gaps. More than one-half of the species surveyed predominantly use only one major natural habitat category, mostly forests, or are highly associated to microhabitats or to specific habitat features (62%, n = 32). Grasslands were the most used habitat (n = 32). Most species apparently will encounter difficulties to move through the landscape (27% and 36% of the species have low and medium movement potential, respectively) and are highly sensitive to human disturbance (48%). Furthermore, a considerable low number of species was frequently recorded in non-natural habitats and considered of low sensitivity (n = 6). Our results offer a wide understanding of relevant habitats and microhabitats for Cerrado birds and can add more reality to future model estimates, enhancing success of current and future conservation initiatives.

The Brazilian Merganser is a threatened species and classified as Critically Endangered. Its world population is estimated to be fewer than 250 individuals surviving in the wild. Currently, the species is known from disjunct populations distributed in the states of Minas Gerais, Goias, and Tocantins (in the Jalapao region). For this study, the stretches of the Preto, Novo, Soninho, and Sono Rivers were surveyed by airboat to better estimate the species distribution in the region. Brazilian Mergansers were found only on the Novo River along a stretch upstream from Da Velha waterfall. Four pairs and a few other adult individuals were identified there. A 50 km stretch of the Novo River was selected for monthly censuses (n = 13) from August 2009 to October 2010 to estimate the relative abundance and population size of the Brazilian Merganser. The Abundance Kilometric Index was 0.125 individuals/ km. The Novo River, from Da Velha waterfall until near its headwaters, is 145 km long and our survey estimated a population of 13.7 individuals. Changes caused by uncontrolled tourist activities on the Novo River, such as rafting during the species’ breeding season, riparian forest deforestation, and proposed hydropower projects, can negatively impact this small Brazilian Merganser population putting it in great risk of local extinction.