Assessing the utility of statistical adjustments for imperfect detection in tropical conservation science

1. In recent years, there has been a fast development of models that adjust for imperfect detection. These models have revolutionised the analysis of field data, and their use has repeatedly demonstrated the importance of sampling design and data quality. There are, however, several practical limitations associated with the use of detectability models which restrict their relevance to tropical conservation science. 2. We outline the main advantages of detectability models, before examining their limitations associated with their applicability to the analysis of tropical communities, rare species and large-scale datasets. Finally, we discuss whether detection probability needs to be controlled before and/or after data collection. 3. Models that adjust for imperfect detection allow ecologists to assess data quality by estimating uncertainty, and to obtain adjusted ecological estimates of populations and communities. Importantly, these models have allowed informed decisions to be made about the conservation and management of target species. 4. Data requirements for obtaining unadjusted estimates are substantially lower than for detectability-adjusted estimates, which require relatively high detection/recapture probabilities and a number of repeated surveys at each location. These requirements can be difficult to meet in large-scale environmental studies where high levels of spatial replication are needed, or in the tropics where communities are composed of many naturally rare species. However, while imperfect detection can only be adjusted statistically, covariates of detection probability can also be controlled through study design. Using three study cases where we controlled for covariates of detection probability through sampling design, we show that the variation in unadjusted ecological estimates from nearly 100 species was qualitatively the same as that obtained from adjusted estimates. Finally, we discuss that the decision as to whether one should control for covariates of detection probability through study design or statistical analyses should be dependent on study objectives. 5. Synthesis and applications. Models that adjust for imperfect detection are an important part of an ecologist's toolkit, but they should not be uniformly adopted in all studies. Ecologists should never let the constraints of models dictate which questions should be pursued or how the data should be analysed, and detectability models are no exception. We argue for pluralism in scientific methods, particularly where cost-effective applied ecological science is needed to inform conservation policy at a range of different scales and in many different systems

Bee diversity responses to forest and open areas in heterogeneous Atlantic Forest

Agriculture driven landscape changes has caused worldwide forest loss and fragmentation, seriously affecting biodiversity and ecosystem services, amongst which pollination is remarkably important. Bees are an essential pollinator group for forest plant populations and food production in tropical landscapes. They are also dependent on forested environments which are essential to maintain their diversity and pollination services. We analyzed bee diversity in contrasting forest and adjacent non-forest patches to evaluate if bees can use complementary non-native environments in heterogeneous altered tropical landscapes. The effect of landscape level heterogeneity and forest amount on bee diversity was also assessed. Our hypothesis was that bee communities would be more rich and diverse inside the forest understory, but due to supplementary foraging behaviors they would be more abundant in non-forested areas where flower availability is higher. We actively sampled bees visiting flowers within forest patches and in surrounding non-forest open areas between the Cantareira and Mantiqueira mountain ranges in São Paulo, Brazil. We found higher bee richness and diversity in open areas than in forest patches, partially denying our initial hypothesis but supporting that bees are more abundant in non-forest areas. We found strong indication that landscapes with higher amount of forest and environmental heterogeneity can provide more resources for bees through resource complementation processes, maintaining their diversity in the landscape. The presence of forest patches close to crop and open areas is of utmost importance for the conservation of bees and pollination services with important consequences for land management in tropical environments

Bee richness and abundance in small fruit farms from the semiarid landscape, NE, Brazil

Bee diversity and current status of native populations is barely known in cropland from semiarid Sergipe, where fruit production is a growing activity among small farmers. Psidium guajava L. (Myrtaceae) is spread among small growers in Canindé de São Francisco and Poço Redondo in Sergipe state, Northeastern Brazil, in semiarid Caatinga, causing landscape change and habitat loss. Available evidences support that cross-pollination provided by bees may increase seed set and fruit production, despite self-pollination. We aimed to access bee richness and abundance within Guava orchard and identify landscape parameters important to these patterns. Survey was conducted in ten Guava orchards during the flowering period (n=10) from May to December 2017. Nine bee species were recorded and the high density and generalist bees Trigona spinipes and Apis mellifera comprised 92% of the flower visitors. No other social native bees were found, and solitary bees were scarce. No significant influence of landscape structure was found for bee richness, while bee abundance was affected by environmental diversity, isolation, and distance to caatinga patches and continuous vegetation reserves. Landscape simplification threatened bee diversity and pollination services. These results highlight the importance of providing bee habitat within farmlands, rearing stingless bees and restoring natural habitats along streams to increase wild bee populations within crops.Bee diversity and the status of native populations are barely known in cropland from semiarid Sergipe, where fruit production is a growing activity among small farmers. Psidium guajava L. (Myrtaceae) is spread among small farmers in Canindé de São Francisco and Poço Redondo in Sergipe state, Northeastern Brazil, in semiarid Caatinga, causing landscape change and habitat loss. Available evidence supports that cross-pollination provided by bees may increase seed set and fruit production, despite self-pollination. We aimed to access bee richness and abundance within the Guava orchard and identify landscape variables influencing them. The survey was conducted in ten Guava orchards during the flowering period (n=10) from May to December 2017. Nine bee species were recorded. No significant effect of landscape structure on richness was detected, maybe because of the low number of bee species recorded. The high-density and generalist bees Trigona spinipes and Apis mellifera comprised 92% of the flower visitors. No other social native bees were found, and solitary bees were scarce. Native bees that are habitat-sensitive (nesting in cavities on tree trunks) and specialized feeders are the losers. Bee abundance was affected by environmental diversity, isolation, and distance to Caatinga patches and continuous vegetation reserves. These results highlight the importance of the adequate management of natural or semi-natural pollinator habitats in the surrounding landscape. Conserving and restoring natural areas is recommended to provide nesting habitats, diversified flower sources, and connectivity within farmland to increase native bee populations, both solitary and social, within the Guava crop. Further studies linking landscape variables and the potential impact on the stability of crop pollination are needed

How are native vegetation and reserves affected by different road types in a Southeastern Brazilian State?

Reducing connectivity, road networks may threaten the effectiveness of natural reserves, thus, representing acritical conservation matter. This work aims to: 1) evaluate the relationship between native vegetation cover and roaddistance; 2) evaluate the extent to which native vegetation and nature reserves are affected by roads. Our study area wasa neotropical landscape in the state of São Paulo, Brazil. We divided the study area into 15 subregions to represent itshigh heterogeneity. First, we demarcated buffer zones of 10 different distances around each road, and quantified thedensity of roads and native vegetation cover. Second, we estimated the area ecologically affected by roads, the roadeffect zone, using buffers of increasing distances according to each road type. The most dense road network was foundin the São Paulo Metropolitan area and the lowest was the Southern Coastline subregion, but this subregion showed thesecond highest expressway density. These two subregions had stronger positive relationships between native vegetationcover and road distance. Almost 10% of São Paulo state, about 6% of the remaining native vegetation, and more than10% of the reserves were ecologically affected by roads. More than 50% of reserves were ecologically affected, andsome have more than 60% of their territory affected. Threats related to proximity of roads, i.e. logging, may reduceeffectiveness of more than 50% of natural reserves. Thus, we propose that identifying priority areas for integral conservationof pristine environments should include mostly remote areas, which are far from larger roads and under lower generalroad influence.FAPESP (Freitas’ post-doctorate fellowship, Proc. 2006/02673- 9

Singing in the Rain Forest: How a Tropical Bird Song Transfers Information

How information transmission processes between individuals are shaped by natural selection is a key question for the understanding of the evolution of acoustic communication systems. Environmental acoustics predict that signal structure will differ depending on general features of the habitat. Social features, like individual spacing and mating behavior, may also be important for the design of communication. Here we present the first experimental study investigating how a tropical rainforest bird, the white-browed warbler Basileuterus leucoblepharus, extracts various information from a received song: species-specific identity, individual identity and location of the sender. Species-specific information is encoded in a resistant acoustic feature and is thus a public signal helping males to reach a wide audience. Conversely, individual identity is supported by song features susceptible to propagation: this private signal is reserved for neighbors. Finally, the receivers can locate the singers by using propagation-induced song modifications. Thus, this communication system is well matched to the acoustic constraints of the rain forest and to the ecological requirements of the species. Our results emphasize that, in a constraining acoustic environment, the efficiency of a sound communication system results from a coding/decoding process particularly well tuned to the acoustic properties of this environment

Negative impacts of dominance on bee communities: Does the influence of invasive honey bees differ from native bees?

Invasive species can reach high abundances and dominate native environments. One of the most impressive examples of ecological invasions is the spread of the African subspecies of the honey bee throughout the Americas, starting from its introduction in a single locality in Brazil. The invasive honey bee is expected to more negatively impact bee community abundance and diversity than native dominant species, but this has not been tested previously. We developed a comprehensive and systematic bee sampling scheme, using a protocol deploying 11,520 pan traps across regions and crops for three years in Brazil. We found that invasive honey bees are now the single most dominant bee species. Such dominance has not only negative consequences for abundance and species richness of native bees but also for overall bee abundance (i.e., strong “numerical” effects of honey bees). Contrary to expectations, honey bees did not have stronger negative impacts than other native bees achieving similar levels of dominance (i.e., lack of negative “identity” effects of honey bees). These effects were markedly consistent across crop species, seasons and years, and were independent from land-use effects. Dominance could be a proxy of bee community degradation and more generally of the severity of ecological invasions.info:eu-repo/semantics/publishedVersio

Spectrum of gluten-related disorders: consensus on new nomenclature and classification

A decade ago celiac disease was considered extremely rare outside Europe and, therefore, was almost completely ignored by health care professionals. In only 10 years, key milestones have moved celiac disease from obscurity into the popular spotlight worldwide. Now we are observing another interesting phenomenon that is generating great confusion among health care professionals. The number of individuals embracing a gluten-free diet (GFD) appears much higher than the projected number of celiac disease patients, fueling a global market of gluten-free products approaching $2.5 billion (US) in global sales in 2010. This trend is supported by the notion that, along with celiac disease, other conditions related to the ingestion of gluten have emerged as health care concerns. This review will summarize our current knowledge about the three main forms of gluten reactions: allergic (wheat allergy), autoimmune (celiac disease, dermatitis herpetiformis and gluten ataxia) and possibly immune-mediated (gluten sensitivity), and also outline pathogenic, clinical and epidemiological differences and propose new nomenclature and classifications

Using playback techniques to develop a method able to attest the presence or absence of birds inside forest fragments

Nosso objetivo foi desenvolver um método para atestar a presença ou ausência de seis espécies de aves (Basileuterus leucoblepharus, Batara cinerea, Carpornis cucullatus, Chiroxiphia caudata, Pyriglena leucoptera e Trogon surrucura) em fragmentos florestais. Foi determinado o horário do dia e época do ano em que o play-back é mais eficiente em atestar a presença dessas aves. Os testes ocorreram na Reserva Florestal do Morro Grande (Cotia, SP). Três horários foram testados (manhã, meio do dia e tarde) ao longo de um ano. O teste G verificou a variação de eficiência entre os diferentes horários, e o teste de Rayleigh a variação anual. A manhã e o meio do dia apresentaram-se mais eficientes que a tarde para B. leucoblepharus, C. caudata e T. surrucura. A única ave a apresentar uma época do ano mais eficiente foi B. cinerea. Para avaliar sua eficiência, a capacidade do método em atestar a presença das aves em 13 fragmentos foi correlacionada com sua abundância nos mesmos. Os testes ocorreram quatro vezes em cada área nos momentos de maior eficiência. Os resultados indicam que C. caudata seja recenseada pelo menos duas vezes por fragmento. Três visitas é o mínimo para B. cinerea, B. leucoblepharus, P. leucoptera e T. surrucura. Para C. cucullatus deve-se ser repetir quatro vezes. O método foi criado para gerar rapidamente dados de presença e ausência em grande quantidade de fragmentos. Essa informação pode auxiliar estudos sobre dinâmica de metapopulações destas espécies.In order to provide rapid access to presence/absence data of six species of birds (Basileuterus leucoblepharus, Batara cinerea, Carpornis cucullatus, Chiroxiphia caudata, Pyriglena leucoptera and Trogon surrucura) inside forest fragments, an efficient playback method was developed. The broadcast of these birds vocalizations was carried out at the Morro Grande Forrest Reserve (Cotia, SP). Playback tests were executed three times a day (sunrise, noon and before sunset) during one year. Daily and seasonal variations in the efficiency of the play-back were tested with G-statistics and the Rayleigh test. Sunrise and noon were more efficient than the period before sunrise to B. leucoblepharus, C. caudata and T. surrucura. The only species to show an annual period of higher rate of response was B. cinerea. To evaluate the real efficiency of the method, 13 forest fragments were surveyed for presence of these birds. The data was compared to the abundance of the birds in these areas. Each fragment was surveyed four times. At least two surveys are needed for C. caudata. Three surveys are the minimum effort to access the distributional pattern of B. leucoblepharus, B. cinerea, P. leucoptera and T. surrucura. Due to its rarity, C. cucullatus must be censused not less than four times. The method developed in the current study was created to provide a rapid access to the patch occupancy patterns of these six species in a large number of fragments. That kind of data may be very useful in studies about metapopulation dynamics and conservation ecology