A New Method for Low Density Distribution Modeling and Near Threatened Species: The Study Case of Plectrohyla Guatemalensis.

We introduce a model that can be used for the description of the distribution of species when there is scarcity of data, based on our previous work (Ballesteros et al. J Math Biol 85(4):31, 2022). We address challenges in modeling species that are seldom observed in nature, for example species included in The International Union for Conservation of Nature's Red List of Threatened Species (IUCN 2023). We introduce a general method and test it using a case study of a near threatened species of amphibians called Plectrohyla Guatemalensis (see IUCN 2023) in a region of the UNESCO natural reserve "Tacaná Volcano", in the border between Mexico and Guatemala. Since threatened species are difficult to find in nature, collected data can be extremely reduced. This produces a mathematical problem in the sense that the usual modeling in terms of Markov random fields representing individuals associated to locations in a grid generates artificial clusters around the observations, which are unreasonable. We propose a different approach in which our random variables describe yearly averages of expectation values of the number of individuals instead of individuals (and they take values on a compact interval). Our approach takes advantage of intuitive insights from environmental properties: in nature individuals are attracted or repulsed by specific features (Ballesteros et al. J Math Biol 85(4):31, 2022). Drawing inspiration from quantum mechanics, we incorporate quantum Hamiltonians into classical statistical mechanics (i.e. Gibbs measures or Markov random fields). The equilibrium between spreading and attractive/repulsive forces governs the behavior of the species, expressed through a global control problem involving an energy operator.

Red List assessment of amphibian species of Ecuador: A multidimensional approach for their conservation.

Ecuador is one of the most biodiverse countries in the world, but faces severe pressures and threats to its natural ecosystems. Numerous species have declined and require to be objectively evaluated and quantified, as a step towards the development of conservation strategies. Herein, we present an updated National Red List Assessment for amphibian species of Ecuador, with one of the most detailed and complete coverages for any Ecuadorian taxonomic group to date. Based on standardized methodologies that integrate taxonomic work, spatial analyses, and ecological niche modeling, we assessed the extinction risk and identified the main threats for all Ecuadorian native amphibians (635 species), using the IUCN Red List Categories and Criteria. Our evaluation reveals that 57% (363 species) are categorized as Threatened, 12% (78 species) as Near Threatened, 4% (26 species) as Data Deficient, and 27% (168 species) as Least Concern. Our assessment almost doubles the number of threatened species in comparison with previous evaluations. In addition to habitat loss, the expansion of the agricultural/cattle raising frontier and other anthropogenic threats (roads, human settlements, and mining/oil activities) amplify the incidence of other pressures as relevant predictors of ecological integrity. Potential synergic effects with climate change and emergent diseases (apparently responsible for the sudden declines), had particular importance amongst the threats sustained by Ecuadorian amphibians. Most threatened species are distributed in montane forests and paramo habitats of the Andes, with nearly 10% of them occurring outside the National System of Protected Areas of the Ecuadorian government. Based on our results, we recommend the following actions: (i) An increase of the National System of Protected Areas to include threatened species. (ii) Supporting the ex/in-situ conservation programs to protect species considered like Critically Endangered and Endangered. (iii) Focalizing research efforts towards the description of new species, as well as species currently categorized as Data Deficient (DD) that may turn out to be threatened. The implementation of the described actions is challenging, but urgent, given the current conservation crisis faced by amphibians.

Coastal sharks and rays in a marine protected area in southern Brazil.

In southern Brazil, we investigated shark and ray capture records in an integral protection marine protection area (MPA) that allows fishing in that area. We found 10 shark and nine ray species, of which 88.5% and 66.2%, respectively, are endangered. Female adults and neonates of both sexes are abundant in the area, with records of stranding of large specimens, postcapture abortions and ovigerous capsules with fresh embryos on the beach. We suggest the application of continuous fisheries monitoring and an increase in guidelines on the capture of endangered species.

A new, narrowly distributed, and critically endangered species of Characidium (Characiformes: Crenuchidae) from the Distrito Federal, Central Brazil

A new species of Characidium is described from the Cerrado biome, in Brasília, Distrito Federal, Central Brazil. The new species can be readily diagnosed by the presence of two or three longitudinal rows of dots along the body sides, absence of bars, by the short pectoral fin, which does not reach the vertical through the dorsal fin origin. Additional useful diagnostic characters are the scaled isthmus, absence of the adipose fin, and the terminal mouth. The new species is only known from the córrego Taquara and its tributaries, a tributary of ribeirão do Gama, upstream from lago Paranoá, in the upper rio Paraná basin. In accordance to the IUCN Red List Categories and Criteria, the new species is categorized as Critically Endangered.(AU)

Uma nova espécie de Characidium é descrita do bioma Cerrado em Brasília, Distrito Federal, Brasil Central. A nova espécie pode ser diagnosticada pela presença de duas ou três fileiras longitudinais de pontos no corpo, ausência de barras e nadadeira peitoral curta, que não alcança a vertical que passa pela origem da nadadeira dorsal. Caracteres adicionais úteis na diagnose são o istmo escamado, a ausência da nadadeira adiposa e a boca terminal. A nova espécie é conhecida apenas do córrego Taquara e seus tributários, tributário do ribeirão do Gama a montante do Lago Paranoá, na bacia do alto rio Paraná. De acordo com os Critérios e Categorias para Listas Vermelhas da IUCN, a nova espécie é categorizada como uma Criticamente Ameaçada.(AU)

Mammals in atlantic forest remnants of Barbacena, Minas Gerais / Mamíferos em remanescentes florestais de mata atlântica, Barbacena, Minas Gerais

Habitat loss and fragmentation are the main causes of biodiversity decline, since changes in environmental and ecological conditions directly affect species richness, abundance, and distribution. This study aimed to identify medium- and large-sized mammals occurring in three Atlantic Forest remnants located in the Barbacena campus of the Federal Institute of Southeast Minas Gerais (IFSudesteMG). The species were recorded in track plots and through active search for direct and indirect signs. 16 species distributed in six orders and 14 families were identified, including some vulnerable and threatened species such as Lycalopex vetulus (meadow fox), Lontra longicaudis (otter), and Callicebus nigrifrons (black-fronted titi monkey). Canis familiaris (domestic dog) and Didelphis sp. (opossum) were the species most frequently observed in the track plots. The largest fragment had the greatest species richness, with 15 species, or 93.75% of the total. The number of species shared among the three sampled areas was 31.2%. The similarities identified between the fragments indicate the need for higher connectivity among them, through the creation of ecological corridors to allow the movement and, consequently, gene flux among the populations, favoring the maintenance of important ecosystem services in the region. Although small, the study area plays a major role in mammal conservation in the region, preserving species from the Cerrado and the Atlantic Forest domains. To reduce potential impacts on the local fauna, management and conservation efforts should be put forward.

A perda e fragmentação de habitats são as principais causas do declínio da biodiversidade, uma vez que as alterações das condições ambientais e ecológicas afetam diretamente a riqueza, a abundância e a distribuição das espécies. O presente trabalho teve como objetivo identificar mamíferos de médio e grande porte em três fragmentos remanescentes de Mata Atlântica, situados no Campus Barbacena do Instituto Federal do Sudeste de Minas Gerais (IFSudesteMG). As espécies foram registradas por meio de parcelas de areia e busca ativa de vestígios diretos e indiretos. Foram identificadas 16 espécies distribuídas em seis ordens e 14 famílias, dentre elas, algumas vulneráveis e ameaçadas como Lycalopex vetulus (raposa do campo), Lontra longicaudis (lontra) e Callicebus nigrifrons (sauá). Canis familiaris (cão doméstico) e Didelphis sp. (gambá) foram mais frequentes nas parcelas de areia. O maior fragmento apresentou maior riqueza, com 15 espécies, 93,75% do total registrado no Campus. O número de espécies compartilhadas nas três áreas amostradas foi 31,2%. Os índices de similaridade registrados entre os fragmentos indicam que há necessidade de maior conectividade entre as áreas através da criação de corredores ecológicos, permitindo assim o deslocamento das espécies e, consequentemente, o maior fluxo gênico, favorecendo a manutenção de importantes serviços ecossistêmicos para a região. Apesar de pequena, a área de estudo desempenha importante papel na conservação dos mamíferos da região, preservando espécies de Cerrado e Mata Atlântica. Com o intuito de reduzir os impactos na fauna local, torna-se necessário a implantação de ações de manejo e conservação.

A new, narrowly distributed, and critically endangered species of Characidium (Characiformes: Crenuchidae) from the Distrito Federal, Central Brazil

A new species of Characidium is described from the Cerrado biome, in Brasília, Distrito Federal, Central Brazil. The new species can be readily diagnosed by the presence of two or three longitudinal rows of dots along the body sides, absence of bars, by the short pectoral fin, which does not reach the vertical through the dorsal fin origin. Additional useful diagnostic characters are the scaled isthmus, absence of the adipose fin, and the terminal mouth. The new species is only known from the córrego Taquara and its tributaries, a tributary of ribeirão do Gama, upstream from lago Paranoá, in the upper rio Paraná basin. In accordance to the IUCN Red List Categories and Criteria, the new species is categorized as Critically Endangered.(AU)

Uma nova espécie de Characidium é descrita do bioma Cerrado em Brasília, Distrito Federal, Brasil Central. A nova espécie pode ser diagnosticada pela presença de duas ou três fileiras longitudinais de pontos no corpo, ausência de barras e nadadeira peitoral curta, que não alcança a vertical que passa pela origem da nadadeira dorsal. Caracteres adicionais úteis na diagnose são o istmo escamado, a ausência da nadadeira adiposa e a boca terminal. A nova espécie é conhecida apenas do córrego Taquara e seus tributários, tributário do ribeirão do Gama a montante do Lago Paranoá, na bacia do alto rio Paraná. De acordo com os Critérios e Categorias para Listas Vermelhas da IUCN, a nova espécie é categorizada como uma Criticamente Ameaçada.(AU)

Evaluation of conservation status of plants in Brazil's Atlantic forest: An ethnoecological approach with Quilombola communities in Serra do Mar State Park.

The Atlantic Forest is considered the fourth most important biodiversity hotspot. Although almost 96% of its original area has been devastated, a large part of its remaining conserved area is inhabited by traditional communities. This research focused on two Quilombola communities who reside within the Núcleo Picinguaba of the Serra do Mar State Park, State of São Paulo, Brazil. The objective was to use a combination of ethnoecological and ecological approaches to select priority species for which to develop participatory conservation and sustainable management plans in protected areas in Brazil. We collaborated with community members to collect ethnobotanical and ethnoecological data and then measured the abundance of native species in local forests through phytosociological sampling. We used this information to assess the degree of threat to useful species using the Conservation Priority Index, adding an additional layer of analysis based on habitat successional categories. We then overlayed those useful species identified as highest risk locally with those federally listed as threatened or endangered. Based on this, we identified three species as priority for the development of sustainable management plans: Virola bicuhyba, Cedrella fissilis and Plinia edulis.

From plentiful to critically endangered: Demographic evidence of the artisanal fisheries impact on the smalltail shark (Carcharhinus porosus) from Northern Brazil.

The smalltail shark, Carcharhinus porosus, was the most abundant elasmobranch species in fisheries off Brazil's northern coast (BNC) in the 1980s, but its population has been declining since the 1990s. For this reason, a demographic analysis is necessary to determine the extent of this decline and the fishing effect on the BNC's population. Therefore, we performed a stochastic demographic analysis of the population in the BNC, and considered its global center of abundance. Smalltail shark specimens (n = 937) were collected with gillnets in Maranhão state, eastern BNC, in the 1980s with sizes ranging between 29.6 and 120.0 cm total length. Most of the individuals (90.6%) caught were juveniles (< 6 years-old), and the mortality and exploitation rates showed that the species was overexploited (92.3% above the fishing mortality corresponding to the population equilibrium threshold). The smalltail shark's biological characteristics, such as slow growth and low fecundity, demonstrate that it is one of the least resilient species among similar sized coastal sharks in the region. All these factors yielded an annual decrease of 28% in the intrinsic population growth rate, resulting in a population decline of more than 90% in only 10 years, and much higher for the current period. This set of features comprising fishing recruitment occurring upon juveniles, overfishing, and intrinsically low resilience make the population unable to sustain fishing pressure and severely hamper biological recruitment, thus causing this drastic population decline. Furthermore, several local extinctions for this species in the northeastern and southeastern regions of Brazil highlight its concerning conservation scenario. Therefore, since similar fisheries characteristics occur throughout its distribution range, C. porosus fits the criteria E of the IUCN Red List for a critically endangered species and urgent conservation measures are needed to prevent its extinction in the near future.

Southernmost distribution limit for endangered Peladillas (Aplochiton taeniatus) and non-native coho salmon (Oncorhynchus kisutch) coexisting within the Cape Horn biosphere reserve, Chile.

The Cape Horn Biosphere Reserve, one of the last wild areas of the planet, is not exempt from the pressures of global change, such as non-native species introductions. During 2018 and 2019 we studied the Róbalo river basin in order to update the diversity and distribution of fishes. Here, we report for the first time the native and endangered "Peladillas" Aplochiton taeniatus and the non-native coho salmon Oncorhynchus kisutch. The coexistence of native and non-native fishes poses a challenge for the management and conservation of aquatic biota from the Cape Horn Biosphere Reserve.

Estimating population sizes to evaluate progress in conservation of endangered golden lion tamarins (Leontopithecus rosalia).

Efforts to reverse the decline of endangered golden lion tamarin monkeys have been relatively successful because the Brazilian organization dedicated to the species' conservation (Associação Mico-Leão-Dourado, AMLD) relies on science-based computer modeling to determine the number of tamarins necessary to achieve demographic and genetic goals, and a process of strategic planning to achieve those goals. Accurate estimates of the numbers of tamarins in forest fragments are essential to evaluate progress in achieving goals and adapt strategies as necessary. In this report we present the results of a new method to survey the number of tamarins in the wild, a modification of the point transect with lures procedure. Using this method, we estimate that in 2014 there were approximately 3,700 golden lion tamarins in 41,400 hectares of Atlantic Forest. Of these, 59% are from remnant wild populations, 34% are descendants of captive-born reintroduced animals and 7% are descendants of wild translocated groups. The number of tamarins and amount of forest estimated in this survey exceeded values necessary to meet AMLD's definition of a viable population, determined to be 2,000 tamarins in 25,000 hectares of connected and protected forest. However, the seven forest blocks and their tamarin populations are not yet adequately connected and protected. AMLD's strategic plan to achieve a viable population of golden lion tamarins includes 12 strategies that mitigate these and other threats or contribute directly to the conservation goal. The point transect with lures survey method provides a way to evaluate progress in achieving that goal and adapt strategies as appropriate.

Spatial distribution analysis of Dicksonia sellowiana Hook. in Araucaria forest fragments with different sizes / Análise da distribuição espacial de Dicksonia sellowiana Hook. em fragmentos de Floresta com Araucária com diferentes tamanhos

Abstract Dicksonia sellowiana Hook. (Dicksoniaceae) is target of extractive exploitation and is threatened with extinction. We analyzed the population structure, the spatial distribution pattern of D. sellowiana and its relationship with environmental parameters within three fragments of Araucaria Forest in Rio Grande do Sul, Brazil. The fragments are of different sizes, namely, large (H1LF) with 246 ha, medium (H2MF) with 57 ha and small (H3SF) with 5.2 ha. Within each site, 1 ha was delimited, divided into 100 subplots (100 m2), of which 20 were selected with a draw. In each subplot, counting of the individuals, the registration of the caudice height and the coverage of leaves (SC) (m2), measurements of photosynthetically active radiation (PAR), canopy opening degree (CO), soil moisture (SM) and litter thickness (LT). The temperature (T) was measured inside each site. A total of 792 plants were sampled, of which 551 were concentrated in H1LF, 108 in H2MF and 133 in H3SF. An average of 1320 ha-1 individuals were estimated. Of the total including the three fragments, 96.9% of the individuals are in the first class of height (up to 0.8 m), indicating a great potential of population development. The spatial distribution pattern (AI) was aggregated in the three populations and the plants presented a heterogeneous total coverage, between 4.73 m2 (H2MF) and 2,223.47 m2 (H1LF). The highest values ​​of SC and SM were more related to the distribution of individuals in H1LF whereas the opposite was recorded in H2MF. The highest values ​​of PAR, LT and CO correlated with the distribution of D. sellowiana in H3SF. In addition to revealing that the H1LF population is among the most dense in southern Brazil, the results demonstrated a significant structural distinction between the interior populations of the fragments, in spite of them being located near to one another and being part of the same natural field matrix.

Resumo Dicksonia sellowiana Hook. (Dicksoniaceae) é alvo de exploração extrativista e encontra-se ameaçada de extinção. Analisamos a estrutura populacional, o padrão de distribuição espacial de D. sellowiana e sua relação com parâmetros ambientais no interior de três fragmentos de Floresta com Araucária, no Rio Grande do Sul (RS), Brasil. Os fragmentos possuem diferentes tamanhos sendo denominados de grande (H1LF) com 246 ha, médio (H2MF) com 57 ha e de pequeno (H3SF) com 5,2 ha. No interior de cada sítio, foi demarcado 1 ha, fracionado em 100 subparcelas (100m2), das quais 20 foram sorteadas. Em cada subparcela foi feita a contagem dos indivíduos, o registro da altura do cáudice e da cobertura (SC) (m2) das folhas, as medições da radiação fotossinteticamente ativa (PAR), grau de abertura do dossel (CO), umidade do solo (SM) e espessura da serapilheira (LT). A temperatura (T) foi medida no interior de cada sítio. Foram amostradas 792 plantas, das quais 551 concentradas no H1LF, 108 no H2MF e 133 no H3SF e em média foram estimados 1320 indivíduos ha-1. Do total dos três fragmentos, 96,9% dos indivíduos estão na primeira classe de altura (até 0,8 m), indicando grande potencial de desenvolvimento das populações. O padrão de distribuição espacial (AI) foi agregado nas três populações e as plantas apresentaram uma cobertura total heterogênea, entre 4,73m2 (H2MF) e 2.223,47m 2 (H1LF). Os maiores valores de SC e de SM foram mais relacionadas com a distribuição dos indivíduos no H1LF enquanto que o contrário foi registrado no H2MF. Os maiores valores de PAR, LT e de CO relacionaram-se com a distribuição de D. sellowiana no H3SF. Além de revelar que a população do H1LF está entre as mais densas já descritas no sul do Brasil, os resultados demonstraram uma significativa distinção estrutural entre as populações dos interiores dos fragmentos com diferentes tamanhos, embora muito próximos geograficamente e inseridos em uma mesma matriz de campo natural.

Potential risk of Batrachochytrium salamandrivorans in Mexico.

The recent decline in populations of European salamanders caused by the chytrid fungus Batrachochytrium salamandrivorans (Bsal) has generated worldwide concern, as it is a major threat to amphibians. Evaluation of the areas most suitable for the establishment of Bsal combined with analysis of the distribution of salamander species could be used to generate and implement biosecurity measures and protect biodiversity at sites with high salamander diversity. In this study, we identified the areas most suitable for the establishment of Bsal in Mexico. Mexico has the second-highest salamander species diversity in the world; thus, we identified areas moderately to highly suitable for the establishment of Bsal with high salamander diversity as potential hotspots for surveillance. Central and Southern Mexico were identified as high-risk zones, with 13 hotspots where 30% of Mexican salamander species occur, including range-restricted species and endangered species. We propose that these hotspots should be thoroughly monitored for the presence of Bsal to prevent the spread of the pathogen if it is introduced to the country.

Spatial distribution analysis of Dicksonia sellowiana Hook. in Araucaria forest fragments with different sizes.

Dicksonia sellowiana Hook. (Dicksoniaceae) is target of extractive exploitation and is threatened with extinction. We analyzed the population structure, the spatial distribution pattern of D. sellowiana and its relationship with environmental parameters within three fragments of Araucaria Forest in Rio Grande do Sul, Brazil. The fragments are of different sizes, namely, large (H1LF) with 246 ha, medium (H2MF) with 57 ha and small (H3SF) with 5.2 ha. Within each site, 1 ha was delimited, divided into 100 subplots (100 m2), of which 20 were selected with a draw. In each subplot, counting of the individuals, the registration of the caudice height and the coverage of leaves (SC) (m2), measurements of photosynthetically active radiation (PAR), canopy opening degree (CO), soil moisture (SM) and litter thickness (LT). The temperature (T) was measured inside each site. A total of 792 plants were sampled, of which 551 were concentrated in H1LF, 108 in H2MF and 133 in H3SF. An average of 1320 ha-1 individuals were estimated. Of the total including the three fragments, 96.9% of the individuals are in the first class of height (up to 0.8 m), indicating a great potential of population development. The spatial distribution pattern (AI) was aggregated in the three populations and the plants presented a heterogeneous total coverage, between 4.73 m2 (H2MF) and 2,223.47 m2 (H1LF). The highest values ​​of SC and SM were more related to the distribution of individuals in H1LF whereas the opposite was recorded in H2MF. The highest values ​​of PAR, LT and CO correlated with the distribution of D. sellowiana in H3SF. In addition to revealing that the H1LF population is among the most dense in southern Brazil, the results demonstrated a significant structural distinction between the interior populations of the fragments, in spite of them being located near to one another and being part of the same natural field matrix.

Combining species distribution modeling and field surveys to reappraise the geographic distribution and conservation status of the threatened thin-spined porcupine (Chaetomys subspinosus).

The threatened thin-spined porcupine (Chaetomys subspinosus), a forest-specialist endemic to the Brazilian Atlantic forest, was rarely detected in the wild during the 20th century. Previous geographic distribution assessments were carried out nearly three decades ago and were based on interview data. We performed extensive field surveys (based on active search and interviews), a literature review, and species distribution modeling to predict and validate a more reliable picture of its geographic distribution and environmental suitability gradient. We identified the main predictors of species' incidence, its conservation status, and pinpointed key areas for species conservation. Our results indicated that C. subspinosus is distributed continuously in the Atlantic forest from southeastern Espirito Santo to central-eastern Sergipe state, totaling 104,326 km2 of occurrence area, although only 3,299 km2 (13.3%) is currently represented by native forests (species habitat). C. subspinosus was absent or at least so rare that it was not detected in more than half of the locations sampled by interviews (53.5%). Our results suggest that populations are sensitive to climatic conditions and habitat loss, becoming abruptly rarer when the remaining forest cover reaches less than 10% area within a region (~ 5,000 km2 scale). This result indicates that the high deforestation level of the Atlantic forest is already close to the limit of regional species resistance. Bahia state still harbors the bulk of the remaining forest with high climatic suitability, and generally under low levels of legal protection. Herein we highlight priority areas and research gaps that could guide decision makers to promote conservation strategies for this threatened species.

Ethnotaxonomy of sharks from tropical waters of Brazil.

BACKGROUND: Accessing folk knowledge from small-scale fishers is an affordable and reliable approach to understand the dynamic and diversity of shark species worldwide, especially of those eventually caught. In this context, ethnotaxonomy (folk identification and classification) may represent an alternative to support sharks fisheries management, especially in data-poor places. This study aimed to investigate fishing and ethnotaxonomy of the main shark species caught by small-scale fisheries from the coastal waters of the Brazilian Northeast. METHODS: Semi-structured and structured interviews were conducted with fishers targeting general aspects of fishing activities and specific topics regarding ethnotaxonomy, capture, and commercialization of sharks. For species identification, an ethnobiological systematic perspective was used to analyze the folk nomenclature and classification criteria. Non-parametric statistical tests were used to verify associations between species caught, fishing gear, and harvest period. RESULTS: Fishers mentioned 73 binomial names, 21 main folk species, and eight synonymies. Some species belonging to the same scientific genus are often named and grouped by the same folk name, with no distinction between species by fishers. Sharks are most landed as bycatch and correspond to less than 5% of the total commercial fisheries in the communities, with socioeconomic value for subsistence consumption and local commercialization. Sharks were said to be mainly caught with hand line and surface long line during the rainy season, while gillnet captures were associated to the dry season. At least three of the species most mentioned by fishers are currently classified as vulnerable and endangered worldwide. CONCLUSIONS: Even though landed sharks account for a small proportion of the fishing catches, their biological and life history features place sharks among the most vulnerable organisms globally. Such an ethnobiological approach towards shark identification may contribute to generate basic information on species caught, their frequency in the landings, and how different species belonging to the same genus can be landed and sold together. This type of information can generate subsidies to the development of conservation and management plans for these fishing resources, where knowledge is scarce.

Effects of Host Interspecific Interaction in the Maculinea-Myrmica Parasite-Host System.

A model of interspecific host competition in a system with one parasite (butterfly-Maculinea) and multiple potential hosts (ants-Myrmica) is presented. Results indicate that host interspecific competition increases the occurrence of multiple host behaviour in Maculinea natural populations but decreases the ability of the parasite populations to adapt to the most abundant host species. These qualitative predictions were compared with data on host specificity, with good agreement. Analysis of the data also indicates that Maculinea teleius and Maculinea arion respond differently to changes in relative host abundances. Maculinea teleius shows a larger fraction of sites where it displays multiple host behaviour and a larger fraction of sites where the niches of the hosts overlap. In some instances, Maculinea teleius is adapted to Myrmica hosts that are present in lower frequencies. Maculinea arion is locally more host-specific and occurs at sites where host interspecific competition is unlikely and is more frequently adapted to the most abundant host species.

Distribution pattern of anurans from three mountain complexes in southeastern Brazil and their conservation implications.

Biogeographic tools support spatial distribution pattern hypotheses and help to determine priority areas for conservation. Our aim was to verify biogeographic patterns for anurans in three mountain complexes in southeastern Brazil, as well as to discuss the status of species conservation recorded and the biogeographical units evaluated. We selected 16 areas distributed in the Serra da Mantiqueira complex, south of Serra do Espinhaço and Serra da Canastra. We used the occurrence (geographic coordinates) of each species in the localities to determine areas of endemism applying the Endemicity Analysis method. We also tested whether similarity between areas was explained by geographic distance (Multiple Regression on distance Matrices-MRM). The Serra do Itatiaia, Serra da Canastra, Plateau of Poços de Caldas and Serra do Cipó were the areas that presented the highest number of species restricted to them. Through the Endemicity Analysis, we identified four areas of endemism with higher scores. The MRM revealed that the geographic distance explained 41% of species dissimilarity between areas. Most of the endemic species from these areas have inaccurate conservation statuses (data deficient or unevaluated). These results highlight the need for greater research efforts towards understanding species restricted by distribution, as well as the priority in conserving these endemic areas.

Estructura de la vegetación leñosa en tres áreas con Selva Baja Caducifolia en el Istmo-Costa de Oaxaca, México / Woody vegetation structure in three areas with Tropical Dry Forest in the Isthmus-Coastal of Oaxaca, Mexico

Resumen La Selva Baja Caducifolia (SBC) es de gran importancia por su biodiversidad. En el Istmo-Costa de Oaxaca, México, se encuentran áreas con SBC y distinta categoría de protección (legislación mexicana): (1) Área Natural Protegida (ANP), (2) Área Destinada Voluntariamente para la Conservación (ADVC) y (3) Área de Uso Común (ADUC). En cada una de ellas se analizó la estructura de vegetación leñosa, plantas con DAP ≥ 2.5 cm, muestreando 15 parcelas de 100 m2. La riqueza observada fue de 90 especies incluidas en 36 familias y corresponde al 80 % (Jackknife) y 85 % (ICE) de la esperada. El análisis de agrupamiento identificó dos grupos con 90 % de disimilitud: el primero (G1) incluyó a todas las parcelas muestreadas del ANP; y el segundo (G2) aglomeró las del ADVC y ADUC. Los índices de Shannon, dominancia de Simpson y diversidad verdadera de Jost para el G1 fueron H'= 2.43, D= 0.21 y qD= 11 y para el G2, H'= 2.76, D= 0.28 y qD= 15, sin diferencias entre grupos (P < 0.05). Las especies con Valor de Importancia Relativa más elevado, en ambos grupos, corresponden a vegetación secundaria. La densidad de especies del G1 fue de 1 829 ind/ha y en el G2 de 2 370 ind/ha. Los promedios de altura (6.8 m) y área basal (19.7 m2/ha) del G1 no variaron significativamente (P < 0.05) con los del G2 (7.9 m y 22.1 m2/ha). Las ADVC y ADUC, semejantes en composición y estructura, difieren del ANP. Se sugiere seguir monitoreando la SBC.

Abstract Tropical dry forest (TDF) is important due to its biodiversity. In the Isthmus-Coastal region of the state of Oaxaca, in Southeast Mexico, there are many areas of TDF with varying categories of legal protection (1) Protected Natural Areas (PNA), (2) Voluntarily Designated Conservation Areas (VDCA) and (3) Areas of Common Use (ACU). In each of these, tree vegetation structure was analysed, recording plants with a DBH ≥ 2.5 cm and sampling 15 plots of 100 m2. Observed richness was 90 species, belonging to 36 families and corresponding to 80 % (Jackknife) and 85 % (ICE) of expected richness. A cluster analysis identified two groups with 90 % dissimilitude: the first (G1) included all the sampled plots in the PNA; and the second (G2), grouped together those from the VDCA and the ACU. The Shannon, Simpson dominance and Jost true diversity indices for G1 were H'= 2.43, D= 0.21 and qD= 11 and for G2, H'= 2.76, D= 0.28 and qD= 15 respectively, with no differences between groups (P < 0.05). The species that presented the highest relative importance value (RIV) in both groups, corresponded to secondary vegetation. Species density of G1 was 1 829 ind/ha and 2 370 ind/ha for G2. Mean height (6.8 m) and basal area (19.7 m2/ha) of G1 did not vary significantly (P < 0.05) when compared to G2 (7.9 m y 22.1 m2/ha). The VDCA and ACU presented similar composition and structure, differing from the PNA. Continual monitoring of the TDF is suggested. Rev. Biol. Trop. 66(2): 863-879. Epub 2018 June 01.