Spix’s Macaw Cyanopsitta spixii, extinct in the wild since 2000, was successfully reintroduced in Brazil in 2022, leading to significant progress, including the hatching of wild chicks. However, recent restrictions on further releases by the Brazilian government have put the reintroduction programme into jeopardy. This study updates our 2023 population viability analysis (PVA) to assess the impact of these delayed releases on the wild population. Using six modelled scenarios, we confirm that without annual supplementation of captive-bred birds, the probability of extinction in the wild remains at 100%. Even a one-time release is insufficient to secure population stability. Our results highlight that those annual releases of at least 20 individuals are necessary to ensure long-term viability, with reduced but still essential growth achievable with 10 birds per year. Supplementation of the wild population does not compromise the long-term viability of the well-established captive population. We urge immediate action to resume the release programme in 2024 to prevent the species from once again facing extinction in the wild.

Spix’s Macaw Cyanopsitta spixii is one of the most endangered Neotropical Psittacidae species. Extinct in the wild in the year 2000, in June 2022 the first cohort of C. spixii was reintroduced to its original habitat. For a successful reintroduction of the species, it is necessary to examine the viability of the population against natural and external threats and the environmental requirements for success. Thus, this paper presents a “Population Viability Analysis” (PVA) for Spix’s Macaw. It used the Vortex and RangeShiftR software, biological and environmental data from a bibliographic survey, and information provided by the field team responsible for the reintroduction of the species, and who work directly with the species in captivity. We found that the minimum viable population (MVP) for reintroduction of the species is 20 individuals. However, considering the impact of disease, drought, hunting, and illegal trafficking, this population can only persist if the release of individuals from captivity occurs annually over the next 20 years combined with the reforestation of natural habitat to support population growth.

Among the forms of anthropogenic disturbance, agricultural land use is one of the main threats to biodiversity. Understanding how interactions between parasites and hosts are affected by agricultural land use allows predictions of how these anthropogenic impacts affect parasites. Although parasitism patterns are affected by agricultural land use, it is noteworthy that different groups of parasites can respond differently to these environmental alterations. While heteroxenous species need more than one host to complete their life cycle and tend to be more harmed by anthropization, monoxenous species, which need only one host to complete their life cycle, tend to be less harmed. In this work, we evaluate how agricultural land use affects the abundance and prevalence of parasitism for monoxenous and heteroxenous helminths in the generalist lizard Tropidurus hispidus in Caatinga Domain, Brazil. We recorded differences in abundance and prevalence of heteroxeneous (higher in conserved areas) and monoxenous helminths (higher in agricultural areas). Heteroxenous helminths that have lizards as definitive hosts are mainly obtained through diet. Tropidurus hispidus predominantly consumes insects, so it is possible that the lower abundance and prevalence of heteroxenous parasites in agricultural areas, beyond habitat simplification, is related to the decrease in the insect population. As monoxenous species do not need an intermediate host, it is possible that this aspect has influenced their greater success in anthropogenic environments than heteroxenous species. This contrasting result reinforces the need for a separate assessment between these groups when evaluating effects of land use.

Cyclopes didactylus, the smallest of all anteaters, inhabits Amazonian and Atlantic forests with an apparently disjunct distribution. Yet, phylogeography reveals historical connections through the forests of the Northeast Region of Brazil. Its populations in this region are classified by the Red List of Threatened Species as Data Deficient and with a trend towards decline. However, Northeast Brazil has a large sampling gap, and the potential distribution of this species has yet to be evaluated. We investigated the potential distribution of C. didactylus to evaluate the hypothesis of a disjunct distribution between Amazonian and Atlantic forests and estimate the amount of protected area in its predicted distribution. We generated a Maxent distribution model using occurrence records, according to the new taxonomic revision of Cyclopes, and selected current bioclimatic variables to evaluate the continuity of the predicted distribution of the species in Northeast Brazil. We also performed past projections to assess historical connections and overlapped maps of protected areas onto their current distribution. Although its distribution is probably disjunct, at least one as-yet-unknown population may be present in the forests of Northeast Brazil, an area poorly protected. The results are useful for targeting field efforts in this under-sampled region.

The carrasco is a dense, shrubby vegetation type that covers the higher parts of table-top mountains in north-eastern Brazil. The vegetation of this phytophysiognomy is often considered to have biogeographical and ecological affinities with the cerrado of Central Brazil, but the biogeographical affinities of its avifauna remain unclear. In recent years, deforestation due to local economic activities has been particularly severe in some carrasco-dominated landscapes. In 2013, we initiated avian surveys at the Fazenda Pau D‘Arco, a privately owned property located on top of the Araripe Plateau, to evaluate the effects of a legal forest management program on the avifauna. Here, we present the results of four years of avian inventories to: i) characterize a well-preserved patch of carrasco vegetation; ii) assess avian biogeographical affinities of this vegetation type; iii) identify associations between managed/unmanaged areas and bird species; and iv) provide baseline data for future avian monitoring studies. Using different survey methods, we provide a list of 148 bird species, including several dry-forest specialists and caatinga endemics. Biogeographically, the avifauna of the carrasco represents a subsample of the Caatinga dry forest, lacking cerrado elements. Forest management significantly affected the distribution of several bird species in the study area. We found that 1/5 of the species (24) recorded during our standardized surveys were significantly associated with either unmanaged (14 species) or managed (10 species) areas. Species such as the Ceará Leaftosser Sclerurus cearensis, a globally vulnerable species, have only been detected in non-managed areas and therefore can be negatively affected by the management program. We also present data on 16 avian taxa with ecological and conservation concerns. By presenting a fairly complete and documented list of the avifauna, we characterize the carrasco avifauna and offer the tools to evaluate the effects of forest management on this poorly known vegetation type.

Unlike well-known global patterns of plant species richness along altitudinal gradients, in the mountainous areas of the Brazilian Caatinga, species richness and diversity reach their maxima near mountain tops. The causes of this unusual pattern are not well understood, and in particular the role of edaphic factors on plant community assembly along these gradients has not been investigated. Our goal was to assess the role of edaphic factors (fertility and soil texture) on plant community composition and structure on two mountains of the Brazilian semi-arid region. In 71 plots (Bodocongó site, twenty-one 200-m2 plots, 401–680 m asl; Arara site, fifty 100-m2 plots, 487–660 m asl) we recorded 3114 individuals representing 61 plant species; in addition, at each plot we collected composite soil samples from 0–20 cm depth. Significant altitude-related changes were observed both for community structure and composition, and edaphic variables. A canonical correspondence analysis allowed the distinction of two groups of plots according to species abundances, indicating a preferential habitat distribution of species depending both on altitude and soil variables. Although soil fertility was lowest at the highest altitudes, these areas had high richness and diversity. Conversely, the more fertile foothills were characterized by the dominance of generalist pioneer species. Despite the relatively short altitudinal range that characterizes the studied mountains, this study elucidates the role of edaphic factors on the floristic composition and species richness patterns on the mountains of the Brazilian semi-arid region.

The Caatinga of north-eastern Brazil is the largest and most diverse seasonally dry tropical forest in the Americas and is home to numerous endemic species. However, only 1.2% of the area is under full protection, and given the ongoing decline of this biome there is an urgent need to expand the protected area network. The Endangered Caatinga howler monkey Alouatta ululata is almost endemic to the Caatinga, and is a potential umbrella species for the protection of its biodiversity. Using all available distribution data and our own surveys we applied Maxent and Zonation spatial modelling to identify the range of A. ululata, and priority conservation areas for the species, maximizing habitat quality and connectivity, and minimizing conservation constraints. The top 10% priority areas cover 34,400 km2 and mostly coincide with good remnants of Caatinga. Only priority areas in the northern part of the species’ range are protected, so it is essential to create new protected areas in the centre and south of the range. Maxent modelling indicates that the species depends on good tree cover, but even inside protected areas we observed recent deforestation, illustrating the urgency to improve management. Maxent also indicated that aridity limits the species' range, and therefore the ongoing aridification of the Caatinga is a threat to its future. The protection of A. ululata requires establishing new protected areas in priority locations and improving management of existing protected areas. Preservation of priority areas for the Caatinga howler monkey also represents an opportunity for the conservation of other important biodiversity in the region.

Species with specific roosting, foraging or breeding requirements are particularly vulnerable to habitat loss and degradation. For bats, the availability and environmental condition of caves can be a limiting factor. The cave specialist Natalus macrourus (formerly Natalus espiritosantensis) is categorized as Near Threatened on the IUCN Red List but as Vulnerable in Brazil, based on a projected population reduction and a decline in its area of occupancy, extent of occurrence and/or quality of habitat. There is a lack of knowledge about the species’ distribution, natural history and ecology, information that is required for conservation. Using new occurrence data and potential distribution modelling we evaluated the distribution of N. macrourus in Brazil, analysed pressures on and threats to the species, and assessed the species’ conservation needs. Natalus macrourus is positively associated with areas with higher probability of cave occurrence and negatively associated with areas of high variation in mean daily temperature and mean annual rainfall. Areas with high environmental suitability for N. macrourus correspond to only 3% of the potential distribution modelled. We estimate that the species has already lost 54% of its natural habitat and that there is < 35% of habitat remaining in areas with high environmental suitability. We calculated that approximately half of the caves in areas with high environmental suitability are < 5 km from mining operations and only 4% of the species’ potential distribution lies within protected areas. Given the strong association of N. macrourus with caves, it is important to protect these habitats, and we recommend that caves where the species is present should receive immediate protection.

A quantitative prediction of global species richness in the lichenized family Trypetheliaceae employing a grid method previously used in similar approaches for the family Graphidaceae and the genus Cora (Hygrophoraceae) is provided. 421 currently known taxa were used as a base for the calculation and we predict a total of nearly 800 species, corresponding to an increase of almost 100%. Most of the unrecognized taxa are predicted to occur in the Neotropics, which have the highest known species richness. The Palaeotropics are less diverse. In contrast to Graphidaceae, which are mostly confined to rainforests, Trypetheliaceae show substantial species richness in dry forest and savannah ecosystems, and future collection efforts should take well-preserved areas representing such ecosystems into consideration.

Gneiss inselbergs in the Caatinga region of Ceará in equatorial Brazil are literally covered with a wide diversity of caloplacoid lichens. This includes two closely related new saxicolous species of Caloplaca, both with the aspect of a Lecanora of the subfusca-aggregate: C. lecanorocarpa has a grey areolate bullate thallus with atranorin on a black prothallus, grey thalline apothecium margin, sessile apothecia with glossy dark brown disc, and ascospores of 10–12×5·0–5·5 μm, with a 5·0–5·5 μm thick septum; and the similar, related C. lecapustulata which mainly differs by the rimose thallus with irregular mushroom-shaped pustules. The phylogenetic position of the two new species has been assessed to be within the Caloplacoideae. A key to all tropical lecanoroid Caloplaca species is provided.

This study aims to understand the distribution of species of Jacquemontia (Convolvulaceae) in Brazil and to determine the centre of endemism of the genus in that country. A database of around 2000 records of samples deposited in 46 herbaria was created. Twenty-one species were classified as widely distributed, of which 14 have continuous distributions and seven have disjunct ones. The remaining 26 species were classified as restricted and among these, 14 were considered endemic and 12 microendemic. The centre of endemism of the genus is in the Espinhaço Range, which traverses Bahia and Minas Gerais. The distribution patterns are discussed and a new assessment for the Red List of Jacquemontia is suggested.

The new species Coniarthonia aurata E. L. Lima, M. Cáceres & Aptroot, Cresponea endosulphurea A. A. Menezes, M. Cáceres & Aptroot, Cryptothecia macrocephala E. L. Lima, M. Cáceres & Aptroot, and Synarthonia sarcographoides Aptroot, A. A. Menezes, E. L. Lima & M. Cáceres are described from Caatinga vegetation in NE Brazil. They were found in the Chapada do Araripe in the state of Ceará and/or the Vale do Catimbau National Park in Pernambuco. Coniarthonia aurata has weakly organized, semiglobose apothecia with golden crystals, and on first impression looks like the anamorph of a Tylophoron. Cresponea endosulphurea has a pigment of the group of xantholepinones in the thallus. It is the first time that a substance from this group is reported from the Arthoniales. Cryptothecia macrocephala has strongly macrocephalic ascospores and contains psoromic acid in the thallus. Synarthonia sarcographoides is only the third species in this rarely found genus. It is characterized within the genus by muriform, brown ascospores, but it is assigned with hesitation to the genus. It is locally quite common.

The new species Cryptothecia fabispora and C. lichexanthonica are described from NE Brazil. The first has domed asci with two large, reniform ascospores and the thallus contains psoromic acid. The second contains lichexanthone and has globose asci. Cryptothecia fabispora was found at the Serra de Itabaiana National Park which represents one of the few rainforest remnants in the state, and is a transitional area with Mata Atlantica influence and also open vegetation spots like Caatinga. It was also found in Caxiuaná in Amazonian Para and may well occur elsewhere. Cryptothecia lichexanthonica was collected at Vale do Catimbau National Park in Pernambuco, which is in a Caatinga area.

The new species Opegrapha subdictyospora is described from NE Brazil. It is only the third species in the genus with (sub)muriform ascospores and is further characterized by the brown pruinose discs. It was collected at Vale do Catimbau National Park in Pernambuco, which is a Caatinga area, where it is locally common.

The new species Pyrenula reginae and P. rubromamillana are described from NE Brazil. Both have a conspicuous red or orange thallus, an inspersed hamathecium and relatively small ascospores, but they differ clearly in colour and ascoma organization.

The blond titi monkey Callicebus barbarabrownae lives in forest fragments in the caatinga (tropical thorn scrub and forest) of north-east Brazil. In 2004–2005 we carried out five surveys to determine its current distribution and conservation status; surveying forest fragments, interviewing local people, and recording vegetation types and patterns of land use. The blond titi monkey occurs mainly in Dense Arboreal Caatinga and Highland Coastal Rainforest in the state of Bahia, at elevations of 241–908 m. Its range extends over 291,438 km2, with an area of occupancy of 2,636 km2. Estimated minimum population was 260 individuals. It was not recorded in any protected area. Cattle ranching favours the persistence of forest fragments for this species, whereas agriculture, subsistence or commercial, does not. Our findings supported the IUCN Red List assessment of Critically Endangered for this species.

Mandevilla (Apocynaceae) is a neotropical genus which is well represented in Brazil. A recent taxonomic revision of the Brazilian species of Mandevilla subgenus Mandevilla included eight new species, one of them from the State of Pernambuco. Nevertheless, while preparing a survey of Apocynaceae from the Brazilian semi-arid region, a new species of the subgenus was recognised. Mandevilla catimbauensis Souza-Silva, Rapini & J.F.Morales is here described and illustrated. It is a twining plant with elliptic, glabrous leaves and hypocrateriform, purple flowers, known only from the Vale do Catimbau National Park, in the State of Pernambuco.

We report the first estimate of jaguar density in the semi-arid caatinga biome of north-eastern Brazil. During August–October 2007, in the Serra da Capivara National Park, we used camera traps to identify and count jaguars. Jaguar abundance and density were calculated using mark-recapture models. In a sampling effort of 1,249 camera-trap-nights we identified 12 adult jaguars and estimated an abundance of 14 ± SE 3.6 jaguars in an area of 524 km2, i.e. a density of 2.67 ± SE 1.00 jaguars per 100 km2. This estimate is higher than in most other Brazilian biomes and indicates Serra da Capivara National Park as an important reserve for protecting jaguars in north-eastern Brazil.

Mean seed dry mass values were determined for 27 species of trees and shrubs in Amazonian caatinga (a forest-type especially short of nitrogen) and for 11 species in adjacent much taller forest on less poor soil. The tall trees (> 15 m) of caatinga have smaller seeds than the tall trees in adjacent forest on less infertile soil (both overall and in six taxonomically controlled comparisons), and than the tall trees in lowland rainforests elsewhere. The smaller seed size is interpreted in terms of a major advantage of keeping up seed number outweighing the marginal advantages of larger seed size. For trees of caatinga and adjacent forest considered together, there is a significantly greater concentration of P and Mg, and almost significantly greater concentration of N, in the embryo-cum-endosperm fraction of smaller-seeded species, but the content per seed of N, P and Mg is smaller in smaller seeds. The mean contribution of the seed coat (including endocarp for pyrenes) was 17% for dry mass, 3% for content of P, 10% for N and Mg, 15% for K, and 30% for Ca.