Human-modified landscapes narrow the isotopic niche of neotropical birds.

Deforestation and habitat loss resulting from land use changes are some of the utmost anthropogenic impacts that threaten tropical birds in human-modified landscapes (HMLs). The degree of these impacts on birds' diet, habitat use, and ecological niche can be measured by isotopic analysis. We investigated whether the isotopic niche width, food resources, and habitat use of bird trophic guilds differed between HMLs and natural landscapes (NLs) using stable carbon (δ13C) and nitrogen isotopes (δ15N). We analyzed feathers of 851 bird individuals from 28 landscapes in the Brazilian Atlantic Forest. We classified landscapes into two groups according to the percentage of forest cover (HMLs ≤ 30%; NLs ≥ 47%), and compared the isotopic niche width and mean values of δ13C and δ15N for each guild between landscape types. The niches of frugivores, insectivores, nectarivores, and omnivores were narrower in HMLs, whereas granivores showed the opposite pattern. In HMLs, nectarivores showed a reduction of 44% in niche width, while granivores presented an expansion of 26%. Individuals in HMLs consumed more resources from agricultural areas (C4 plants), but almost all guilds showed a preference for forest resources (C3 plants) in both landscape types, except granivores. Degraded and fragmented landscapes typically present a lower availability of habitat and food resources for many species, which was reflected by the reduction in niche width of birds in HMLs. Therefore, to protect the diversity of guilds in HMLs, landscape management strategies that offer birds more diverse habitats must be implemented in tropical regions.

The resilient frugivorous fauna of an urban forest fragment and its potential role in vegetation enrichment.

Anthropocentric defaunation affects critical ecological processes, such as seed dispersal, putting ecosystems and biomes at risk, and leading to habitat impoverishment. Diverse restoration techniques could reverse the process of habitat impoverishment. However, in most of the restoration efforts, only vegetation cover is targeted. Fauna and flora are treated as isolated components, neglecting a key component of ecosystems' functioning, the ecological interactions. We tested whether the resilient frugivorous generalist fauna can improve habitat quality by dispersing native plant species through the use of fruit feeders as in a semideciduous seasonal urban forest fragment. A total of 32 sampling points was selected at a heavily degraded 251-ha urban forest fragment, with feeders installed at two heights monitored by camera-traps. Variable quantities of native fruits of 27 zoochorous species were offered alternately in the feeders. Based on more than 36,000 h of video records, Turdus leucomelas (Class Aves), Sapajus nigritus (Class Mammalia), and Salvator merianae (Class Reptilia) were recorded ingesting the highest fruit species richness. Didelphis albiventris (Class Mammalia) was the most frequent visitor but consumed only pulp in most of the visits. The frugivorous birds were recorded at a high visitation rate and consumed a wider variety of fruits. Our study opens a new avenue to combine the traditional approach of ecosystems recovery and ecological interactions restauration in an urban forest fragment. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11252-020-01080-5.

Ecological literacy and beyond: Problem-based learning for future professionals.

Ecological science contributes to solving a broad range of environmental problems. However, lack of ecological literacy in practice often limits application of this knowledge. In this paper, we highlight a critical but often overlooked demand on ecological literacy: to enable professionals of various careers to apply scientific knowledge when faced with environmental problems. Current university courses on ecology often fail to persuade students that ecological science provides important tools for environmental problem solving. We propose problem-based learning to improve the understanding of ecological science and its usefulness for real-world environmental issues that professionals in careers as diverse as engineering, public health, architecture, social sciences, or management will address. Courses should set clear learning objectives for cognitive skills they expect students to acquire. Thus, professionals in different fields will be enabled to improve environmental decision-making processes and to participate effectively in multidisciplinary work groups charged with tackling environmental issues.

Non-volant small mammals at an Atlantic forest area situated nearby a limestone quarry (Limeira quarry), state of São Paulo, Brazil / Pequenos mamíferos não-voadores em uma área de Mata Atlântica adjacente à mina de cimento Limeira, São Paulo, Brasil

Our aim was to survey the non-flying small mammals inhabiting an Atlantic forest area situated nearby a limestone quarry (Limeira quarry), located at Ribeirão Grande municipality (SP), southeastern Brazil. Species were captured with pitfall and Sherman traps along eight pairs of 60 m transects distributed at four different distances from the quarry (60, 220, 740 and 1300 m). Between October 2005 and January 2008, 20 small mammal species (11 rodents and nine marsupials) were captured through 4080 pitfall trap-nights and 2040 Sherman trap-nights. The high values of richness, diversity (H' = 2.65) and equability (J = 0.88), and the presence of endemic and threatened species indicates a preserved study site and small mammal assemblage. Marmosops incanus, Monodelphis americana and Oligoryzomys nigripes were the commonest species at the study site. Trapping sites located closer to the quarry (60 and 220 m away from the quarry) presented lower richness and were dominated by disturbance-tolerant species, such as O. nigripes, that usually benefit from habitat alterations. On the other hand, sites located away from the quarry and closer to Serra do Mar Protected Area (740 and 1300 m away from the quarry) presented higher richness and diversity, and a higher abundance of disturbance-intolerant species. These results suggest a negative distance-dependent impact of quarrying on small mammal communities. In this way, our results point out to the importance of long-term monitoring of quarrying impacts on small non-flying mammal communities and populations, and the need of conservation strategies in order to ensure species persistence in these areas.

O objetivo desse estudo foi elaborar uma lista das espécies de pequenos mamíferos não-voadores que ocorrem em uma região de Mata Atlântica localizada nas proximidades de uma área de mineração de calcário (Mina Limeira), situada no município de Ribeirão Grande (SP), sudeste do Brasil. Para tal, foram montadas estações de captura contendo linhas de balde e armadilhas do tipo Sherman em oito transectos de 60 m, agrupados em pares e localizados a diferentes distâncias da cava da mina (60, 220, 740 e 1300 m de distância), partindo da área antropizada em direção à área de proteção ambiental da Serra do Mar. Entre outubro de 2005 e janeiro de 2008, com um esforço de 4080 baldes-noite e 2040 armadilhas-noite, foram capturadas 20 espécies de pequenos mamíferos, sendo 11 roedores e nove marsupiais. A alta riqueza, diversidade (H' = 2,65) e equabilidade (J = 0,88) estimada na área de estudo, além da presença de espécies endêmicas e ameaçadas, indicam o grau de preservação da área de estudo e da assembléia de pequenos mamíferos. As espécies mais comuns foram Marmosops incanus, Monodelphis americana e Oligoryzomys nigripes. Os transectos localizados mais próximos da cava (60 e 220 m de distância) foram dominados por espécies indicadoras de habitats alterados, como O. nigripes, que tende a proliferar nessas situações. Por outro lado, os sítios mais distantes (740 e 1300 m de distância da cava) apresentaram maior riqueza e diversidade, e espécies mais sensíveis a perturbações. Esses resultados sugerem um possível impacto negativo dependente de distância em relação à mina de calcário. Dessa maneira, nossos resultados apontam para a importância de monitoramentos de longo prazo sobre os impactos da mineração sobre as populações e a comunidade de pequenos mamíferos não-voadores, além da elaboração de planos de conservação para assegurar a persistência das espécies na região.

Seed inflow to a forest patch promoted by understory frugivorous birds / Entrada de sementes em um fragmento florestal promovida por aves frugívoras de subosque

We studied the contribution of understory frugivorous birds to the seed inflow into a late successional Atlantic forest patch in southeastern Brazil. Five sampling units were established in the study site, each composed of a line of six mist nets and two adjacent plots containing six seed traps. Immigrant seed species were more frequent in seed traps during the rainy season, when fruit production was higher. On the other hand, the frequency of occurrence of immigrant seed species found in fecal samples of the understory frugivores was higher during the dry season. Although understory frugivorous birds were not responsible for the temporal pattern of the seed rain, they can play an important role in bringing edge plant species that will eventually colonize forest gaps, contributing to forest patch dynamics.

Estudamos a contribuição de aves frugívoras de subosque para a entrada de sementes em uma mancha de Floresta Atlântica secundária em estado avançado de regeneração no sudeste do Brasil. Foram estabelecidas cinco unidades amostrais, cada uma composta por uma linha de seis redes de neblina e duas parcelas adjacentes contendo seis coletores de sementes. Espécies de sementes imigrantes foram encontradas mais frequentemente nos coletores durante a estação chuvosa, quando houve maior produção de frutos. Por outro lado, a frequência de ocorrência de espécies imigrantes nas amostras fecais de aves de subosque foi maior durante a estação seca. Embora aves frugívoras de subosque não tenham sido determinantes para o padrão temporal da chuva de sementes, podem desempenhar um papel importante ao trazerem espécies de plantas de borda que poderão colonizar clareiras, contribuindo assim para a dinâmica de manchas florestais.

Potential seed dispersal by Didelphis albiventris (Marsupialia, Didelphidae) in highly disturbed environment / Potencial dispersão de sementes por Didelphis albiventris (Marsupialia, Didelphidae) em ambiente altamente perturbado

Urban forests are usually isolated and highly disturbed, however they are important shelters for tolerant animal species. Their food habits expose the different ecological roles these animals perform in the habitat. We analyzed the contribution of Didelphis albiventris Lund (1840), as a seed disperser, to the vegetation renewal of an urban forest fragment, describing its frugivorous diet and testing the viability of ingested seeds. Both male and female of white-eared opossum included a vast variety of items in their diet, mainly invertebrates and fruits. Fruits were consumed during all year round and seasonality was not observed. The majority of consumed fruits was from pioneer plant species, which is common in disturbed areas, in accordance to the opossum's opportunistic habits. The viability of ingested seeds, evaluated by linear logistic regression models applied to data from germination tests, was different of the seeds collected directly from ripe fruits; it varied among species, maybe due to the intrinsic characteristics of plant species. As a highly generalist species, D. albiventris can inhabit disturbed environments and then disperse seeds from pioneer plants, where the vegetation must be restored. It is crucial that this process does not depend only on the specialist frugivores, which are frequently absent in urban forest fragments. Therefore, the presence of generalist species of secondary environments has its importance emphasized.

Florestas urbanas são geralmente isoladas e altamente degradadas; contudo são importantes abrigos para espécies de animais tolerantes. Os hábitos alimentares destes animais explicitam os diferentes papéis ecológicos que eles desempenham no hábitat. Nós analisamos a contribuição de Didelphis albiventris Lund (1840) como dispersor de sementes para a regeneração da vegetação de um fragmento florestal urbano. Para isso, descrevemos sua dieta frugívora e testamos a viabilidade das sementes por ele ingeridas. Tanto machos quanto fêmeas de gambá-de-orelha-branca incluiram uma grande variedade de itens alimentares na dieta, principalmente invertebrados e frutos. Frutos foram consumidos durante todo o ano e a sazonalidade não foi observada. A maioria das sementes defecadas era proveniente de plantas pioneiras, comuns em ambientes perturbados, o que concorda com seu hábito oportunista. A viabilidade das sementes ingeridas, verificada mediante modelos de regressão logística linear aplicada a dados de testes de germinação, foi diferente das sementes obtidas de frutos maduros e variou entre espécies, talvez devido a características intrínsecas da planta. Enquanto uma espécie generalista, D. albiventris é capaz de habitar ambientes perturbados, e dispersar as sementes de plantas de estágio inicial de sucessão, onde a vegetação necessita ser restaurada. É essencial que este processo não dependa exclusivamente de frugívoros especialistas, que na maioria das vezes estão ausentes nos fragmentos florestais urbanos. Consequentemente, a presença de espécies generalistas de ambientes secundários tem sua importância enfatizada.