Factors that Determine Human Acceptance of Black Bears

After being extirpated from their historical distribution, black bears (Ursus americanus) have recolonized eastern Oklahoma, USA. As bears continue to establish populations in the region, understanding the cognitive factors that influence human acceptance of black bears will play an important role in facilitating coexistence. We hypothesized that a variety of variables drawing from the cognitive hierarchy and risk perception frameworks would affect human acceptance of black bears in eastern Oklahoma. We collected data using a mail-back questionnaire administered to residents of eastern Oklahoma between August and November 2018. Perceptions of the current black bear population size, attitudes toward bears, valuing Oklahoma wildlife, behavioral intentions, and level of formal education all positively influenced acceptance of bears. Risk-averse respondents and women were less accepting. Outreach to women and encouraging residents to reduce conflict by adopting bear-safe behaviors may help raise acceptance capacity for black bears. © 2021 The Wildlife Society.     

Using river color to predict Amazonian floodplain forest avifaunas in the world's largest blackwater river basin

Despite the importance of rivers in Amazonian biogeography, avian distribution patterns in river‐created habitats (i.e., floodplain forests) have been sparsely addressed. Here, we explore geographic variation in floodplain forest avifaunas, specifically regarding one of the most striking aspects of the Amazon: the diversity of river “colors” (i.e., types, based on the color of the water). We sampled the avifauna at 30 sites, located in 17 different rivers (nine black‐ and eight whitewater), in the Rio Negro basin, northwestern Brazil. Our sampling comprised ten 15‐min point‐counts per site, distributed every 500–1000 m along the river. We recorded a total of 352 bird species, many of which occurred in both river types. Although bird species richness was similar among rivers, we found significant differences in species composition. Nearly 14 percent of the species were significantly associated with one or the other river type. Most floodplain forest specialists occurred predominantly in whitewater rivers, whereas species that are typically associated with white‐sand habitats occurred in blackwater. Despite significant distinctions between river types, occurrence patterns and levels of habitat association differed among indicator species and may vary in the same species throughout its global distribution. There were also “intermediate” avifauna in some of our sites, suggesting that continuous parameters characterizing river types structure species turnover. The water color‐based classification of Amazonian rivers represents a simple and powerful predictor of the floodplain forest avifauna, offering a stimulating starting point for understanding patterns of floodplain bird distributions and for prioritizing conservation efforts in these overlooked habitats. Abstract in Portuguese is available with online material.     

Amazon fish bacterial communities show structural convergence along widespread hydrochemical gradients

The world's richest freshwater fish community thrives in gradients of contrasting environments in Amazonia, ranging from ion‐poor acidic black waters, to ion‐rich circumneutral white waters. These hydrochemical gradients structure Amazonian fish assemblages via ecological speciation events. Fish bacterial communities contain an important genetic heritage essential for their hosts' survival and are also involved in adaptive divergence via niche adaptation processes, but the extent to which they evolve in response to hydrochemical gradients in Amazonia is unknown. Here we investigated bacterial communities (gut and skin mucus) of two ecologically and phylogenetically divergent host species (Mesonauta festivus and Serrasalmus rhombeus) distributed throughout these hydrochemical gradients. The goal was to characterize intra‐ and interspecific Amazonian fish microbiome variations across multiple scales. Using a 16S metabarcoding approach, we investigated the microbiota of 43 wild M. festivus, 32 S. rhombeus and seven water samples, collected at seven sampling sites encompassing both water colours. Taxonomical structures of bacterial communities from both host species were significantly correlated to the environmental continua of magnesium, sodium, dissolved organic carbon, calcium, dissolved O₂, pH, potassium, hardness and chloride. Analysis of discriminating features in community structures across multiple scales demonstrated intra‐ and interspecific structural parallelisms in the response to the hydrochemical gradients. Together, these parallelisms suggest the action of selection on bacterial community structures along Amazonian hydrochemical gradients. Functional approaches along with reciprocal transplant experiments will provide further insights on the potential contribution of Amazonian fish microbiomes in host adaptation and ecological speciation events.     

Three fishes in one: cryptic species in an Amazonian floodplain forest specialist

Accurately describing biodiversity in tropical regions such as Amazonia is difficult because of insufficient morphological inventories and the lack of studies on the distribution of genetic diversity. Aquatic organisms from Amazonian flooded forests are generally expected to move laterally along the forests during the annual inundation cycle, a behaviour that should promote admixture of populations and reduce within‐drainage speciation. We used an unprecedented fine‐scale sampling effort and multiple DNA markers to quantify region‐wide population differentiation in an Amazonian floodplain forest specialist, the black‐wing hatchet fish Carnegiella marthae ( Myers, 1927 ). Our study revealed three previously unsuspected and ancient cryptic species of black‐wing hatchet fish in the Rio Negro floodplain (RNF), in central Amazonia. Two species produce occasional first‐generation hybrids. The third and rarer species, although found in extreme sympatry with another species, appears to be reproductively isolated, and also differs in external morphology and dentition. Our findings have important implications for guiding conservation management because C. marthae is harvested commercially in the RNF ornamental fishery. They also suggest that the diversity of Amazonian ichthyofauna is vastly underestimated, including that found in landscapes lacking contemporary barriers to account for population divergence and speciation. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102 , 391–403.     

Community-level interactions and functional ecology of major workers in the hyperdiverse ground-foraging Pheidole (Hymenoptera, Formicidae) of Amazonian Ecuador

Ants of the genus Pheidole are abundant and hyperdiverse, particularly in Neotropical rainforests. Very little is known, however, about the degree of ecological and behavioral differentiation of coexisting species comprising Pheidole communities. Additionally, the ecological role of the major worker subcaste, thought to be significant to the diversification of Pheidole, is poorly understood. We investigated the ecology and behavior of a ground-foraging Pheidole community of at least 56 species in Amazonian Ecuador. Pheidole species differed strongly in tolerance to flooding, nest site usage, foraging range, major worker foraging, and control of baits, but not in daily activity or ability to discover baits. A molecular phylogeny based on mitochondrial DNA was characterized by poorly resolved basal relationships and long terminal branches, suggesting an ancient diversification of many Pheidole lineages. Comparison of well-supported sister species suggests that both phylogenetic history and ecologically induced differentiation contribute to interspecific variation in Amazonian Pheidole. Ground-nesting species had larger major workers than twig-nesting species, whereas dominant species with stronger recruitment had a higher proportional abundance of major workers at baits. Variation among species suggests the presence of behavioral groups within the Amazonian Pheidole community that appear to segregate according to nest site usage and/or tolerance to flooding disturbance. Our results suggest an important role for major worker differentiation in the diversification of Pheidole.     

Riodocea (Rubiaceae, Gardenieae), a new genus from the Brazilian Atlantic forest

The genusRiodocea is here described from material collected in the várzea forest of the Rio Doce Valley, northern Espírito Santo.Riodocea is a monotypic genus probably related to the Amazonian endemicKutchubaea. A line drawing shows general morphology and photomicrographs show pollen morphology ofRiodocea pulcherrima. Distribution maps ofRiodocea andKutchubaea are included. The valley of the Rio Doce is here included in the Bahian Hylaea, defined as a subregion of the Brazilian Atlantic forest. The connections between the Amazonian Hylaea and the Bahian Hylaea are discussed.     

Interspecific variation in gill size is correlated to ambient dissolved oxygen in the Amazonian electric fish Brachyhypopomus (Gymnotiformes: Hypopomidae)

Gymnotiform electric fish assemblage structure is strongly correlated to dissolved oxygen (DO) availability, which exhibits considerable heterogeneity among Amazonian aquatic systems. DO is known to influence the respiratory morphology of gymnotiform fishes, and yet species-level variation among congeners endemic to alternative DO regimes has not been examined. We describe the DO environment experienced by four congeneric species of gymnotiforms (Brachyhypopomus) and correlate this to quantitative variation in a suite of gill metrics. Whitewater floodplain lakes flanking nutrient-rich whitewater rivers are seasonally hypoxic, exhibiting oxygen concentrations close to 0 mg/l from late April until September. In contrast, DO levels in blackwater floodplain lakes and in terra firme forest stream habitats remain high throughout the year. Two common species of Brachyhypopomus restricted to periodically anoxic whitewater floodplain exhibited a substantially greater gill size than two common species restricted to the perpetually well-oxygenated waters of blackwater floodplain lakes and terra firme stream systems. Discriminant Function Analysis (DFA) based on gill metrics separated the species that live in seasonally anoxic whitewater floodplain species from those that live in perpetually-well oxygenated habitats. Our observations suggest a history of adaptive divergence in the gill morphology of Brachyhypopomus associated with oxygen availability.     

Spatial organization and population density of the fish community of the litter banks within a central Amazonian blackwater stream

Results of a study of the fish community of the leaf litter banks in the lower reaches of the Taruma-Mirim, a small central Amazonian stream is presented. The Taruma-Mirim is an acidic, blackwater, forest stream which flows through igapo forest and enters the Rio Negro close to Manaus. The commonly held view that these blackwaters hold an impoverished ichthyofauna is challenged. The studied litter banks hold about 20 species of fish, all of which were found to live within distinct subregions of the habitat. Average fish density was about 100 individuals m⁻². Absolute population sizes were found to be remarkably small; within a 200 m² area the most abundant species had a population size of about 10⁴ and the least abundant <10² individuals. It is argued that high species richness linked to specialized habitat requirements and small population size indicates considerable population stability. The factors leading to the evolution of such species richness are discussed.     

Anthropogenic impact of mercury accumulation in fish from the Rio Madeira and Rio Negro rivers (Amazonia)

Fish is an important concentrator of mono-methyl mercury and the main route to human contamination. We compared fish Hg bioaccumulation (within similar weight ranges) in two Amazonian river habitats during high-water seasons. The Rio Madeira has been greatly impacted by agriculture, alluvial gold extraction, and a hydroelectric reservoir, whereas the Rio Negro is much less affected by these human activities. The species at the top of the food web, Hoplias malabaricus (piscivorous; 80-668 ng Hg/g) and Cichla spp. (piscivorous; 42–747 ng Hg/g) showed the highest range of Hg concentrations. Nonpiscivorous species with comparable weight range, such as Potamorhina latior (detritivorous; 20–157 ng Hg/g) and Myleus torquatus (herbivorous; 2–182 ng Hg/g), had lower Hg concentrations. Triportheus elongatus (omnivorous; 5–350 ng Hg/g), with the lowest weight range, also showed a low range of Hg concentrations. Despite the Rio Madeira's higher sediment load as well as environmental impacts (deforestation, agriculture, hydroelectric reservoir, and alluvial gold mining) on natural Hg release, fish Hg bioaccumulation was no different between the two river habitats for nonpiscivorous species. In this small observational study only the species at the top of the food web (M. torquatus, Cichla spp, T. elongatus) showed higher mean Hg concentrations in the Rio Madeira than the dominantly wilderness habitat of the Rio Negro.     

Physical and Chemical Studies of Lago Tupé; a Central Amazonian Black Water “Ria Lake”

Lago Tupé, a Central Amazonian dystrophic black water “Ria lake” (blocked valley lake), lateral to the Rio Negro, was studied at all depths for a year. Physical and chemical results of that study are presented here as a prelude to the microbiological studies. The lake's origin and morphology are discussed. Results concerned with thermal properties, suspended matter and dissolved solids are presented, in addition to results on ionic composition, alkalinity, hardness, pH and dissolved oxygen. Nutrient studies include section of phosphate and nitrogen and conclude with silicate results.     

Protection by natural blackwater against disturbances in ion fluxes caused by low pH exposure in freshwater stingrays endemic to the Rio Negro

Stenohaline freshwater stingrays (Potamotrygon spp.) are endemic to the very dilute (Na(+), Cl(-), Ca2(+) 300 micromol L(-1) in reference water (low DOC) to about 100 micromol L(-1) in blackwater (high DOC). In reference water, both JNain and JClin were inhibited >90%, both JNaout and JClout more than doubled, and J(Amm) did not change at pH 4.0. In blackwater, the inhibition of influxes was attenuated, the increases in outflux did not occur, and J(Amm) increased by 60% at pH 4.0. Addition of 100 micromol L(-1) Ca(2+) to reference water prevented the increases in JNaout and JClout and allowed J(Amm) to increase at pH 4.0, which demonstrates that the gills are sensitive to Ca(2+). However, addition of Ca(2+) to blackwater had no effect on the responses to pH 4.0. Addition of commercial humic acid to reference water did not duplicate the effects of natural Rio Negro blackwater at the same DOC level; instead, it greatly exacerbated the increases in JNaout and JClout at low pH and prevented any protective influence of added Ca(2+). Thus, blackwater DOC appears to be very different from commercial humic acid. Biogeochemical modeling indicated that blackwater DOC prevents Ca(2+) binding, but not H(+) binding, to the gills and that the protective effects of blackwater cannot be attributed to its higher buffer capacity or its elevated Al or Fe levels. Natural DOC may act directly at the gills at low pH to exert a protective effect and, when doing so, may override any protective action of Ca(2+) that might otherwise occur.     

Classification of central amazon lakes on the basis of their microbiological and physico-chemical characteristics

Twenty-four Central Amazonian Várzea and Ria lakes, lateral to the Rio Negro and the Rio Solimões, were studied for a year and are classified here in terms of physical, chemical and microbiological characteristics. White water (W), mixed water (M) and black water (B) lakes are ranked according to bacterial densities, electrical conductivity, pH, DO, POC, Fe, Si0₂ and PO₄ consumption in the following order W > M > B. The range of V_max decreased as net primary production increased. Further differentiation among the three lake types is made on the basis of dominant algal species and species diversity.     

Extension of the geographic range of Ateles chamek (Primates,Atelidae): evidence of river-barrier crossing by an amazonian primate

The black-faced black spider monkey (Ateles chamek) is endangered because of hunting and habitat loss. There are many gaps in our understanding of its geographic distribution. The Ucayali–Solimões–Amazon fluvial complex is currently recognized as the northern boundary of the species’ range, although published reports have indicated that it occurs north of the Rio Solimões. In this study we investigate published records, generate new field records, and assess the current information concerning the northern boundary of this species’ range. We conducted the study at the Mamirauá Sustainable Development Reserve in the central Brazilian Amazon, an area of 1,124,000 ha that consists entirely of Amazonian flooded forest (várzea). We collected data on the occurrence of the species from museum specimens and through field surveys, including interviews with local residents, direct observations, and the collection of new museum specimens. We confirmed the presence of A. chamek at 17 locations in the reserve, one of which was an island formed by a river bend cut-off that would have effectively taken any resident spider to the (new) north bank of the Solimões. We therefore conclude that fluvial dynamics were involved in creating the conditions for the dispersal and colonization of the species on the northern bank of the Rio Solimões. The data we present extends the known distribution of the species and increases its representation in protected areas.     

Why is the neon tetra so bright? Coloration for mirror-image projection to confuse predators? “Mirror-image decoy” hypothesis

The neon tetra (Paracheirodon innesi), which inhabits blackwater streams of the Amazon basin, has extremely bright coloration characterized by metallic blue-green stripes. To clarify the ecological function of this coloration, we examined the appearance of living neon tetra. They changed color in response to lighting and background conditions, and became less conspicuous under each condition to the human eye. Although they appeared bright in colorless clear water, their stripes appeared darker in blackwater. In addition, the visible area of their stripes was small and their brightness decreased, unless they were observed within a limited viewing angle (approximately 30° above the horizon). The results show that from the viewpoint of approaching submerged predators, a bright mirror image of the stripes is projected onto the underside of the water’s surface, providing a dramatic visual target while the real fish remains less conspicuous. Based on these results, we hypothesize that the neon tetra’s bright coloration is an effective predator evasion strategy that confuses predators using bright mirror images.     

Useful Species Richness,Proportion of Exotic Species,and Market Orientation on Amazonian Dark Earths and Oxisols<Superscript>1</Superscript>

Useful Species Richness, Proportion of Exotic Species, and Market Orientation on Amazonian Dark Earths and Oxisols Anthropogenic soils of Amazonia, known as Amazonian Dark Earths (ADE), are environments with elevated soil fertility that can produce crops that otherwise yield poorly on the leached and highly acidic Oxisols that dominate much of the basin. While ADE sites near urban centers often attract commercial horticultural production of nutrient–demanding exotics, these soils are also considered possibly unique reservoirs of endemic agrobiodiversity because of their relationship to pre–Columbian indigenous occupation. Through botanical surveys and interviews with smallholder farmers, this study compared useful species richness, proportion of exotic species, and market orientation of farms situated on ADE and non–anthropogenic Oxisols in the municipality of Borba in Central Brazilian Amazonia. Species richness was similar on Amazonian Dark Earth and Oxisol farms (19.6 spp vs. 18.3 spp); however, ADE farms showed significantly higher proportions of exotic species (39% vs. 26%; p = 0.025). Furthermore, ADE farms in Borba demonstrated significantly higher market orientation (61.0% vs. 47.3%; p = 0.028), likely a result of the advantage of Amazonian Dark Earths for production of crops that are nutrient–demanding or pH–sensitive crops that have higher values in the nearby regional market of Manaus.     

The association between circadian rest-activity patterns and the behavioral and psychological symptoms depending on the cognitive status in Japanese nursing-home residents

ABSTRACT

Background: Limited information is available on the relationship between sleep disturbances during nighttime and the behavioral and psychological symptoms of dementia in older nursing-home residents. However, a few reports on the association between the circadian rest-activity rhythm and the behavioral and psychological symptoms of dementia in older residents have been published. The main objective of the present study was to examine the association among the circadian rest-activity rhythm, behavioral and psychological symptoms, and the cognitive function status among older individuals living in facilities. Method: The investigation was conducted from September 2017 to February 2018, and participants were recruited from five nursing homes in Akita prefecture, Japan, after obtaining patient agreement to participate in the study. To measure nonparametric circadian rest-activity parameters such as interdaily stability, intradaily variability, relative amplitude, mean of the least active 5-h period, and mean of the most active 10-h period, Actigraph devices were worn on the participants’ nondominant wrists continuously for seven days. The score or classification of the cognitive status and the severity of the behavioral and psychological symptoms of dementia (BPSD) were assessed using the clinical dementia rating (CDR) and the dementia behavior disturbance scale (DBD), respectively. The binomial logistic regression model was applied to clarify which kinds of circadian rest-activity parameters predicted the cognitive status in nursing home residents as well as the BPSD outcome. A multi-level model was also used to examine the association between the nonparametric rest-activity parameters and the BPSD outcome explained by the cognitive status among older individuals in facilities. Results: Seventy-seven participants (49 residents with dementia, and 28 residents without dementia) were included in this study. According to the binomial logistic regression analysis after adjusting for covariates, the classification of the cognitive status for older residents was associated with the DBD score (odds ratio, 1.22; 95% confidence interval [CI], 1.08, 1.38; p < 0.001), the IS (odds ratio, 0.01; 95% CI, 0.00, 1.00; p = 0.05) and the L5 (odds ratio, 0.99; 95% CI, 0.99, 1.00; p = 0.05). The results of a multi-level model also indicated that the IV at individual-level was significantly associated with the DBD score for nursing home residents, with the CDR score at cluster-level as an explanatory variable. As well, a significant association between the RA at individual level and the DBD score was observed in a multi-level model explained by the CDR score at cluster-level. Conclusion: Of these models, the multi-level model provided grounds for our proposal that the fragmentation or the amplitude of rest-activity parameters might be associated with the outcome of BPSD, considering the cognitive status of older individuals in different facilities. The findings offer practical insight into the prevention of BPSD and the improvement of rest-activity rhythms in rehabilitative care in nursing homes.     

极地和深海环境中低温噬菌体研究进展

极地和深海是地球上较为独特的生态系统,生活在其中的生物由于长期处于低温、寡营养和黑暗封闭的环境中,大多缺乏基本的光合作用,而被认为是研究生命进化和地球环境演化等问题的＂活化石＂。在这样的极端环境中,低温噬菌体的丰度却很高,越来越多的证据表明它们在维持这类环境的生态平衡和调控生物地球化学循环等方面扮演着非常重要的角色。对极地与深海中低温噬菌体的研究进行简要综述。     

Behavioral Responses of Nursing Home Residents to Visits From a Person with a Dog,a Robot Seal or aToy Cat

Previous studies suggest that contact with dogs can positively affect the wellbeing of elderly people in nursing homes, but there is a lack of research investigating the causal pathways of these effects. One such path- way may relate to the behavioral responses of the elderly when interacting with a dog. The present study compared the immediate behavioral responses of nursing home residents to bi-weekly visits from a person accompanied by either a dog, a robot seal (PARO®), or a soft toy cat, using a randomized controlled design. A total of 100 nursing home residents com- pleted the study. Each participant received a total of 12 visits, during which their behaviors, including interactions between the visitor and the accom- panying animal (real or artificial), were recorded. Also, data on cognitive im- pairment, presence of depressive symptoms, age, time lived in the nursing home, dementia diagnoses, and gender were collected. We found that the immediate responses to, and interaction with, the visiting animal depended on the type of animal that was brought along. The dog and the interactive robot seal triggered the most interaction, in the form of physical contact (F(2,103) = 7.50, p < 0.001), eye contact (F(4,151) = 6.26, p < 0.001), and verbal communication (F(4,195) = 2.87, p < 0.05). As well, the cognitive impairment level of the residents affected with whom they interacted. The higher the cognitive impairment level, the more interaction was directed toward the animal and less toward humans, regardless of visit type (F(2,101) = 4.10, p < 0.05). The dogs and the robot seal stimulated the residents to more in- teraction, compared with the toy cat, but the robot seal failed to maintain the attention at the same level over time. The cognitive functioning of the residents correlated with the level of interaction, and this needs to be studied further.     

RIVERSCAPE GENETICS IDENTIFIES REPLICATED ECOLOGICAL DIVERGENCE ACROSS AN AMAZONIAN ECOTONE

Ecological speciation involves the evolution of reproductive isolation and niche divergence in the absence of a physical barrier to gene flow. The process is one of the most controversial topics of the speciation debate, particularly in tropical regions. Here, we investigate ecologically based divergence across an Amazonian ecotone in the electric fish, Steatogenys elegans. We combine phylogenetics, genome scans, and population genetics with a recently developed individual‐based evolutionary landscape genetics approach that incorporates selection. This framework is used to assess the relative contributions of geography and divergent natural selection between environments as biodiversity drivers. We report on two closely related and sympatric lineages that exemplify how divergent selection across a major Amazonian aquatic ecotone (i.e., between rivers with markedly different hydrochemical properties) may result in replicated ecologically mediated speciation. The results link selection across an ecological gradient with reproductive isolation and we propose that assortative mating based on water color may be driving the divergence. Divergence resulting from ecologically driven selection highlights the importance of considering environmental heterogeneity in studies of speciation in tropical regions. Furthermore, we show that framing ecological speciation in a spatially explicit evolutionary landscape genetics framework provides an important first step in exploring a wide range of the potential effects of spatial dependence in natural selection.