Avian biodiversity assessment studies in a Neotropical wetland - the combination of sampling methods makes the difference

In studies of avian diversity, many different methods have been applied. Since methodological approaches may affect research results, the choice of a given methodology must be consistent with the scientific objectives. The aim of this study was to investigate how different methodologies with their intrinsic limitations help detect and monitor birds to evaluate how they complement each other in the survey of species. Three different assessment methods, mist nets, point counts, and autonomous acoustic recordings were used to serve this purpose in a study of different Pantanal habitats, such as savannas and forests. The point counts detected more species (126 species) than the two other methods autonomous acoustic recordings (113 species) and mist nets (79 species). We observed significant differences in the number of species detected by mist nets and the other two methods. Each survey method identified exclusive species. When comparing habitats, all three methods showed significant differences in bird species composition. Savannas were richer in bird species than forests, and replacement was the main driver responsible for the differences in beta diversity between the habitats. The three methodologies, when applied together, proved to be complementary in avian species detection.

Comparing the efficiency of monofilament and regular nets for capturing bats.

Regular nylon or polyester mist nets used for capturing bats have several drawbacks, particularly that they are inefficient at sampling insectivorous species. One possible alternative is to use monofilament nets, whose netting is made of single strands of yarn instead of several as regular nets, making them less detectable. To date, only one study has quantified the differences in capture rates between monofilament and regular mist nets for the study of bats, yet surprisingly, its findings suggest that the latter are more efficient than the former. Here, we provide further evidence of the differences in sampling efficiency between these two nets. We captured 90 individuals and 14 species in regular nets and 125 individuals and 20 species in monofilament nets. The use of monofilament nets increased overall capture rates, particularly for insectivorous species. Species accumulation curves indicate that samples based on regular nets are significantly underestimating species diversity, most notably as these nets fail at sampling rare species. We show that incorporating monofilament nets into bat studies offers an opportunity to expand records of different guilds and rare bat species and to improve our understanding of poorly known bat assemblages while using a popular, relatively cheap and portable sampling method.

Structure of understory bird communities in Atlantic Forest Remnants in Northeastern Brazil / Estrutura das comunidades de aves de remanescentes de Mata Atlântica no nordeste do Brasil

The Atlantic Forest in the State of Paraíba integrates the Pernambuco Center of Endemism. The present work investigated understory bird communities of three of its remnants using ten mist nets installed at eight different points of the forest understory of each area. We captured 333 birds of 44 species and 19 families. Bird richness and abundance did not differ between the three remnants (KW = 6.08; p = 0.04 and KW = 10.54; p = 0.004). The composition was little similar among them, and each area presented high species diversity and evenness. The most captured species were Arremon taciturnus (n = 40), Chiroxiphia pareola (n = 32) and Conopophaga melanops (n = 28). C. melanops has a local threat status of “vulnerable” and is considered endemic. Endangered and endemic species each represented 15.91% of the captures. Both Reserva Biológica Guaribas areas had the highest number of threatened species, while Reserva Particular do Patrimônio Natural Engenho Gargaú showed the highest number of endemic and understory insectivorous species, which indicates a better quality status in comparison to the other two. These results show the importance of the remnants to bird conservation in Northeastern Brazil.(AU)

A Mata Atlântica do Estado da Paraíba integra o Centro de Endemismo Pernambuco. O presente estudo investigou comunidades de aves de sub-bosque de três remanescentes da região, por meio da captura com redes de neblina. Dez redes foram posicionadas no sub-bosque florestal em oito pontos distintos ao longo de cada remanescente. Foram capturados 333 indivíduos de 44 espécies, divididas em 19 famílias. A riqueza e a abundância diferiram entre as comunidades amostradas (KW = 6,08; p = 0,04 e KW = 10,54; p = 0,004). A composição específica foi pouco similar entre elas e cada área apresentou elevada diversidade e equitabilidade na distribuição de espécies. As espécies mais representativas foram Arremon taciturnus (n = 40), Chiroxiphia pareola (n = 32) e Conopophaga melanops (n = 28), sendo este último táxon vulnerável e endêmico. As duas áreas da Reserva Biológica Guaribas tiveram o maior número de espécies ameaçadas, enquanto que a Reserva Particular do Patrimônio Natural Engenho Gargaú apresentou o maior número de espécies endêmicas, assim como de insetívoros de sub-bosque, sugerindo melhor qualidade em comparação aos outros dois. Esses resultados apontam a importância que os remanescentes estudados têm para a conservação da avifauna no nordeste brasileiro.(AU)

Structure of understory bird communities in Atlantic Forest Remnants in Northeastern Brazil / Estrutura das comunidades de aves de remanescentes de Mata Atlântica no nordeste do Brasil

The Atlantic Forest in the State of Paraíba integrates the Pernambuco Center of Endemism. The present work investigated understory bird communities of three of its remnants using ten mist nets installed at eight different points of the forest understory of each area. We captured 333 birds of 44 species and 19 families. Bird richness and abundance did not differ between the three remnants (KW = 6.08; p = 0.04 and KW = 10.54; p = 0.004). The composition was little similar among them, and each area presented high species diversity and evenness. The most captured species were Arremon taciturnus (n = 40), Chiroxiphia pareola (n = 32) and Conopophaga melanops (n = 28). C. melanops has a local threat status of “vulnerable” and is considered endemic. Endangered and endemic species each represented 15.91% of the captures. Both Reserva Biológica Guaribas areas had the highest number of threatened species, while Reserva Particular do Patrimônio Natural Engenho Gargaú showed the highest number of endemic and understory insectivorous species, which indicates a better quality status in comparison to the other two. These results show the importance of the remnants to bird conservation in Northeastern Brazil.

A Mata Atlântica do Estado da Paraíba integra o Centro de Endemismo Pernambuco. O presente estudo investigou comunidades de aves de sub-bosque de três remanescentes da região, por meio da captura com redes de neblina. Dez redes foram posicionadas no sub-bosque florestal em oito pontos distintos ao longo de cada remanescente. Foram capturados 333 indivíduos de 44 espécies, divididas em 19 famílias. A riqueza e a abundância diferiram entre as comunidades amostradas (KW = 6,08; p = 0,04 e KW = 10,54; p = 0,004). A composição específica foi pouco similar entre elas e cada área apresentou elevada diversidade e equitabilidade na distribuição de espécies. As espécies mais representativas foram Arremon taciturnus (n = 40), Chiroxiphia pareola (n = 32) e Conopophaga melanops (n = 28), sendo este último táxon vulnerável e endêmico. As duas áreas da Reserva Biológica Guaribas tiveram o maior número de espécies ameaçadas, enquanto que a Reserva Particular do Patrimônio Natural Engenho Gargaú apresentou o maior número de espécies endêmicas, assim como de insetívoros de sub-bosque, sugerindo melhor qualidade em comparação aos outros dois. Esses resultados apontam a importância que os remanescentes estudados têm para a conservação da avifauna no nordeste brasileiro.

ATLANTIC BIRDS: a data set of bird species from the Brazilian Atlantic Forest.

South America holds 30% of the world's avifauna, with the Atlantic Forest representing one of the richest regions of the Neotropics. Here we have compiled a data set on Brazilian Atlantic Forest bird occurrence (150,423) and abundance samples (N = 832 bird species; 33,119 bird individuals) using multiple methods, including qualitative surveys, mist nets, point counts, and line transects). We used four main sources of data: museum collections, on-line databases, literature sources, and unpublished reports. The data set comprises 4,122 localities and data from 1815 to 2017. Most studies were conducted in the Florestas de Interior (1,510 localities) and Serra do Mar (1,280 localities) biogeographic sub-regions. Considering the three main quantitative methods (mist net, point count, and line transect), we compiled abundance data for 745 species in 576 communities. In the data set, the most frequent species were Basileuterus culicivorus, Cyclaris gujanensis, and Conophaga lineata. There were 71 singletons, such as Lipaugus conditus and Calyptura cristata. We suggest that this small number of records reinforces the critical situation of these taxa in the Atlantic Forest. The information provided in this data set can be used for macroecological studies and to foster conservation strategies in this biodiversity hotspot. No copyright restrictions are associated with the data set. Please cite this Data Paper if data are used in publications and teaching events.

ATLANTIC BATS: a data set of bat communities from the Atlantic Forests of South America.

Bats are the second most diverse mammal order and they provide vital ecosystem functions (e.g., pollination, seed dispersal, and nutrient flux in caves) and services (e.g., crop pest suppression). Bats are also important vectors of infectious diseases, harboring more than 100 different virus types. In the present study, we compiled information on bat communities from the Atlantic Forests of South America, a species-rich biome that is highly threatened by habitat loss and fragmentation. The ATLANTIC BATS data set comprises 135 quantitative studies carried out in 205 sites, which cover most vegetation types of the tropical and subtropical Atlantic Forest: dense ombrophilous forest, mixed ombrophilous forest, semideciduous forest, deciduous forest, savanna, steppe, and open ombrophilous forest. The data set includes information on more than 90,000 captures of 98 bat species of eight families. Species richness averaged 12.1 per site, with a median value of 10 species (ranging from 1 to 53 species). Six species occurred in more than 50% of the communities: Artibeus lituratus, Carollia perspicillata, Sturnira lilium, Artibeus fimbriatus, Glossophaga soricina, and Platyrrhinus lineatus. The number of captures divided by sampling effort, a proxy for abundance, varied from 0.000001 to 0.77 individuals·h-1 ·m-2 (0.04 ± 0.007 individuals·h-1 ·m-2 ). Our data set reveals a hyper-dominance of eight species that together that comprise 80% of all captures: Platyrrhinus lineatus (2.3%), Molossus molossus (2.8%), Artibeus obscurus (3.4%), Artibeus planirostris (5.2%), Artibeus fimbriatus (7%), Sturnira lilium (14.5%), Carollia perspicillata (15.6%), and Artibeus lituratus (29.2%).

Opportunistic Predation of Artibeus lituratus (Chiroptera, Phyllostomidae) by the Marsupial Marmosops incanus (Didelphidae, Didelphimorphia) in the Atlantic Forest, Minas Gerais

Marmosops incanus (Lund, 1840) is an abundant marsupial species in the primary and secondary forests of the Atlantic Forest, similarly to the fruit-eating bat Artibeus lituratus (Olfers, 1818), which is commonly recorded in forest regions and rural and urban areas. A new predation activity by the opportunistic marsupial species Marmosops incanus on the fruit-eating bat Artibeus lituratus, trapped in a mist-net, was recorded during a chiropterofauna study in the Atlantic Forest of the State of Minas Gerais, Brazil. It is known that bats are part of the diet of several vertebrates, many of which are mammals; however, the prey-predator relationship between Marmosops incanus and Artibeus lituratus recorded in this study describes a predation relationship never reported before, contributing to enhance the knowledge on this topic.(AU)

Opportunistic Predation of Artibeus lituratus (Chiroptera, Phyllostomidae) by the Marsupial Marmosops incanus (Didelphidae, Didelphimorphia) in the Atlantic Forest, Minas Gerais

Marmosops incanus (Lund, 1840) is an abundant marsupial species in the primary and secondary forests of the Atlantic Forest, similarly to the fruit-eating bat Artibeus lituratus (Olfers, 1818), which is commonly recorded in forest regions and rural and urban areas. A new predation activity by the opportunistic marsupial species Marmosops incanus on the fruit-eating bat Artibeus lituratus, trapped in a mist-net, was recorded during a chiropterofauna study in the Atlantic Forest of the State of Minas Gerais, Brazil. It is known that bats are part of the diet of several vertebrates, many of which are mammals; however, the prey-predator relationship between Marmosops incanus and Artibeus lituratus recorded in this study describes a predation relationship never reported before, contributing to enhance the knowledge on this topic.

Rain effects in the capture of bats in a coastal island in southeastern Brazil / Efeito da chuva na captura de morcegos em uma ilha da costa sul do Rio de Janeiro, Brasil

Climatic factors are difficult to be analyzed because of their intrinsic unpredictability. For example, rain and wind occur in different intensities and in different nights each year. The objective of this work was to analyze the effects of the rain in the capture success of bats in an island in southeastern Brazil. A total of 31 sampling nights resulted in 2000 captures of 28 species, 1507 of which were obtained in nights without rain and 493 captures in rainy nights. The relationship between the total of captures and the species richness was observed for nights without rain as for rainy nights. The species richness and the capture efficiency in every night for all of the species were significantly higher for the nights without rain. The differences in feeding guilds were observed for the insectivorous species among the nights without rain and with rain heavy intensity, and nectar-feeding species among nights without rain and with rain intensities moderate and heavy. Heavy rain shows different effects in the bat species, generally inhibiting the activity or reducing the capture frequency.

Os fatores climáticos são os mais difíceis de serem analisados, pois variam de forma imprevisível, ocorrendo chuvas e ventos em diferentes intensidades e em diferentes noites a cada ano. Este estudo teve como objetivo testar o efeito da chuva no sucesso de captura, das espécies mais frequentes de morcegos em uma localidade no litoral sudoeste do Estado do Rio de Janeiro. Totalizaram-se 31 noites de coletas com 2.000 capturas de 28 espécies. Obtiveram-se 1.507 capturas para noites sem chuva e 493 capturas em noites com chuvas. A relação entre o total de capturas e a riqueza de espécies foi observada tanto para noites sem chuva quanto para noites com chuva. A riqueza de espécies e a eficiência de captura em cada noite para todas as espécies foram significativamente maiores para as noites sem chuva do que para as noites com chuva, sendo que entre as guildas foi observada diferença para as espécies insetívoras entre as noites sem chuva e as com chuva muito intensa, havendo influência também nas espécies nectarívoras entre noites sem chuva e com intensidade moderada e intensidade alta. Chuvas fortes apresentam efeito diferenciado entre as espécies de morcegos podendo inibir a atividade ou diminuir a capturabilidade.

Rain effects in the capture of bats in a coastal island in southeastern Brazil / Efeito da chuva na captura de morcegos em uma ilha da costa sul do Rio de Janeiro, Brasil

Climatic factors are difficult to be analyzed because of their intrinsic unpredictability. For example, rain and wind occur in different intensities and in different nights each year. The objective of this work was to analyze the effects of the rain in the capture success of bats in an island in southeastern Brazil. A total of 31 sampling nights resulted in 2000 captures of 28 species, 1507 of which were obtained in nights without rain and 493 captures in rainy nights. The relationship between the total of captures and the species richness was observed for nights without rain as for rainy nights. The species richness and the capture efficiency in every night for all of the species were significantly higher for the nights without rain. The differences in feeding guilds were observed for the insectivorous species among the nights without rain and with rain heavy intensity, and nectar-feeding species among nights without rain and with rain intensities moderate and heavy. Heavy rain shows different effects in the bat species, generally inhibiting the activity or reducing the capture frequency.

Os fatores climáticos são os mais difíceis de serem analisados, pois variam de forma imprevisível, ocorrendo chuvas e ventos em diferentes intensidades e em diferentes noites a cada ano. Este estudo teve como objetivo testar o efeito da chuva no sucesso de captura, das espécies mais frequentes de morcegos em uma localidade no litoral sudoeste do Estado do Rio de Janeiro. Totalizaram-se 31 noites de coletas com 2.000 capturas de 28 espécies. Obtiveram-se 1.507 capturas para noites sem chuva e 493 capturas em noites com chuvas. A relação entre o total de capturas e a riqueza de espécies foi observada tanto para noites sem chuva quanto para noites com chuva. A riqueza de espécies e a eficiência de captura em cada noite para todas as espécies foram significativamente maiores para as noites sem chuva do que para as noites com chuva, sendo que entre as guildas foi observada diferença para as espécies insetívoras entre as noites sem chuva e as com chuva muito intensa, havendo influência também nas espécies nectarívoras entre noites sem chuva e com intensidade moderada e intensidade alta. Chuvas fortes apresentam efeito diferenciado entre as espécies de morcegos podendo inibir a atividade ou diminuir a capturabilidade.

Predation of bats (Phyllostomidae) captured in mist nets for Chironectes minimus (Zimmermann, 1780) and lifting previous on the subject of predators what present the same behaviour / Predação de morcegos (Phyllostomidae) pela cuíca dágua Chironectes minimus (Zimmermann, 1780) (Didelphimorphia, Didelphidae) e uma breve revisão de predação em Chiroptera

Bats are predated for some of vertebrates and invertebrates. Some opportunistic species preys these animals prisoners in nests during procedures of capture in field. This study records the predation of Carollia perspicillata (Linnaeus, 1758) and Sturnira lilium (E. Geoffroy, 1810) for Chironectes minimus (Zimmermann, 1780) on riparian forest of the brook Talhadinho belonging of the São Paulo, São Paulo, Southeast Brazil, and also presents a lifting previous of mammalian what they present the same one behavior opportunistic predatory, discussing measures simple to avoid this type of predation.

Morcegos são predados por uma variedade de animais vertebrados e invertebrados. Algumas espécies de predadores oportunistas predam morcegos presos em redes durante atividades de pesquisas. Este estudo registra a predação de Carollia perspicillata (Linnaeus, 1758) e de Sturnira lilium (E. Geoffroy, 1810) pela cuíca dágua Chironectes minimus (Zimmermann, 1780) na mata ciliar do córrego Talhadinho, pertencente ao município de Talhados, São Paulo, Sudeste do Brasil, e também apresenta um levantamento de mamíferos que apresentam o mesmo comportamento oportunista, discutindo sugestões para evitar este tipo de predação.

Predation of bats (Phyllostomidae) captured in mist nets for Chironectes minimus (Zimmermann, 1780) and lifting previous on the subject of predators what present the same behaviour / Predação de morcegos (Phyllostomidae) pela cuíca dágua Chironectes minimus (Zimmermann, 1780) (Didelphimorphia, Didelphidae) e uma breve revisão de predação em Chiroptera

Bats are predated for some of vertebrates and invertebrates. Some opportunistic species preys these animals prisoners in nests during procedures of capture in field. This study records the predation of Carollia perspicillata (Linnaeus, 1758) and Sturnira lilium (E. Geoffroy, 1810) for Chironectes minimus (Zimmermann, 1780) on riparian forest of the brook Talhadinho belonging of the São Paulo, São Paulo, Southeast Brazil, and also presents a lifting previous of mammalian what they present the same one behavior opportunistic predatory, discussing measures simple to avoid this type of predation.

Morcegos são predados por uma variedade de animais vertebrados e invertebrados. Algumas espécies de predadores oportunistas predam morcegos presos em redes durante atividades de pesquisas. Este estudo registra a predação de Carollia perspicillata (Linnaeus, 1758) e de Sturnira lilium (E. Geoffroy, 1810) pela cuíca dágua Chironectes minimus (Zimmermann, 1780) na mata ciliar do córrego Talhadinho, pertencente ao município de Talhados, São Paulo, Sudeste do Brasil, e também apresenta um levantamento de mamíferos que apresentam o mesmo comportamento oportunista, discutindo sugestões para evitar este tipo de predação.

Mesh size and bird capture rates in Mato Grosso do Sul State, Brazil

Mist-nets alternating 36-mm and 61-mm mesh in woods and low vegetation of "cerrado" (Brazilian savanna) tested bird-capture efficiency relative to bird length and mass. Of 1,296 birds captured and 102 species, 785 (93 species) were with 36-m mesh and 511 (69 species) with 61-mm mesh. The 61-mm mesh improved capture rates only for some larger species; so, in general, 36-mm mesh mist-nets are more appropriate for field work in "cerrado" areas.

Este trabalho teve por objetivo comparar a eficiência na captura de aves, relativamente à massa corporal e ao comprimento total, de redes ornitológicas de malhas de 36 e 61 mm. O estudo foi realizado em área de Cerrado, dispondo-se as redes alternadamente em transectos lineares. Das 1.296 capturas e 102 espécies, 785 (93 espécies) foram efetuadas com redes de 36 mm e 511 (69 espécies) com redes de malha de 61 mm. De modo geral, as últimas redes não aumentaram as taxas de capturas, exceto para as espécies maiores e com maior massa corporal, e as redes de malha de 36 mm seriam mais apropriadas para estudos em área de Cerrado.