69 research outputs found

    Effect of polymorphic colour vision for fruit detection in the spider monkey Ateles geoffroyi, and its implications for the maintenance of polymorphic colour vision in platyrrhine monkeys

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    Most platyrrhine monkeys have an X-linked tri-allelic polymorphism for medium and long wavelength (M/L) sensitive cone photopigments. These pigments' sensitivity maxima (λmax) range from 535 to 562 nm. All animals also have an autosomally coded short-wavelength-sensitive (S) cone pigment. In populations with three M/L alleles there are six different colour vision phenotypes. Heterozygous females have trichromatic colour vision, while males and homozygous females are dichromats. The selective basis for this polymorphism is not understood, but is probably affected by the costs and benefits of trichromatic compared to dichromatic colour vision. For example, it has been suggested that trichromats are better equipped than dichromats to detect fruit against a leaf background. To investigate this possibility, we modeled fruit detection by various colour vision phenotypes present in the frugivorous spider monkey, Ateles geoffroyi. Our study population is thought to have three M/L alleles with cone pigment λmax values close to 535, 550 and 562 nm. The model predicted that all trichromat phenotypes had an advantage over dichromats, and the 535/562 nm phenotype was best; however, the model predicted that dichromats could detect all of the fruit species consumed by spider monkeys. We conclude that the heterozygote advantage experienced by females may be the most plausible explanation for the maintenance of this polymorphism in A. geoffroyi. Nevertheless, more studies need to evaluate social foraging behaviour and the performance of different phenotypes of other New World monkeys to determine if this is a global explanation for this phenomena or more specific to A. geofforyi

    Book Review Roundtable: Kathryn E. Stoner’s Russia Resurrected: Its Power and Purpose in a New Global Order and James Reilly’s Orchestration: China’s Economic Statecraft Across Asia and Europe

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    This double book review roundtable examines the drivers and international influence of Russia and China. It features Kathryn Stoner’s Russia Resurrected: Its Power and Purpose in a New Global Order and James Reilly’s Orchestration: China’s Economic Statecraft Across Asia and Europe

    Flower consumption, ambient temperature and rainfall modulate drinking behavior in a folivorous-frugivorous arboreal mammal

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    Water is vital for the survival of any species because of its key role in most physiological processes. However, little is known about the non-food-related water sources exploited by arboreal mammals, the seasonality of their drinking behavior and its potential drivers, including diet composition, temperature, and rainfall. We investigated this subject in 14 wild groups of brown howler monkeys (Alouatta guariba clamitans) inhabiting small, medium, and large Atlantic Forest fragments in southern Brazil. We found a wide variation in the mean rate of drinking among groups (range = 0–16 records/day). Streams (44% of 1,258 records) and treeholes (26%) were the major types of water sources, followed by bromeliads in the canopy (16%), pools (11%), and rivers (3%). The type of source influenced whether howlers used a hand to access the water or not. Drinking tended to be evenly distributed throughout the year, except for a slightly lower number of records in the spring than in the other seasons, but it was unevenly distributed during the day. It increased in the afternoon in all groups, particularly during temperature peaks around 15:00 and 17:00. We found via generalized linear mixed modelling that the daily frequency of drinking was mainly influenced negatively by flower consumption and positively by weekly rainfall and ambient temperature, whereas fragment size and the consumption of fruit and leaves played negligible roles. Overall, we confirm the importance of preformed water in flowers to satisfy the howler’s water needs, whereas the influence of the climatic variables is compatible with the ‘thermoregulation/dehydration-avoiding hypothesis’. In sum, we found that irrespective of habitat characteristics, brown howlers seem to seek a positive water balance by complementing the water present in the diet with drinking water, even when it is associated with a high predation risk in terrestrial sources.Coordinación de la formación del personal de nivel superior/[2755/2010]/CAPES/BrasilNational Council for scientific and Technological Development/[303306/2013-0]/CNPq/BrasilNational Council for scientific and Technological Development/[304475/2018-1]/CNPq/BrasilNational Council for scientific and Technological Development/[140641/2016-5]/CNPq/BrasilUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí

    Factors affecting nectar sugar composition in chiropterophilic plants

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    AbstractMost pollinators prefer the sugars present in the nectar they consume, so it has been hypothesized that they have molded nectar trait evolution. However, nectar-feeding bats do not exhibit preferences for the sugars present in their diet. We analyzed the role that biochemical and ecological factors could play in shaping the nectar traits of chiropterophilic plants. We studied nectar traits and flower production in 49 plant species. We evaluated the relationship between nectar concentration and sugar composition using phylogenetically independent contrasts and if nectar traits were related to flower production using a Manova. We found that 42 species produced high hexoses nectars, and 7 species produced sucrose rich nectars. Phylogenetically independent contrasts showed that nectar concentration was negatively related to glucose content, positively related to fructose content, and was not related to sucrose content. A negative relationship was found from glucose and fructose contents to sucrose content, and glucose content was negatively related to fructose content. Finally, we did not found any relationship between nectar traits and the plants’ flowering strategies. We conclude that bat physiology and the relative low evolutionary time of the interaction between plants and bats may determine the lack of pattern in the nectar characteristics of chiropterophilic plants

    Relationship between Spatial Working Memory Performance and Diet Specialization in Two Sympatric Nectar Bats

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    Behavioural ecologists increasingly recognise spatial memory as one the most influential cognitive traits involved in evolutionary processes. In particular, spatial working memory (SWM), i.e. the ability of animals to store temporarily useful information for current foraging tasks, determines the foraging efficiency of individuals. As a consequence, SWM also has the potential to influence competitive abilities and to affect patterns of sympatric occurrence among closely related species. The present study aims at comparing the efficiency of SWM between generalist (Glossophaga soricina) and specialist (Leptonycteris yerbabuenae) nectarivorous bats at flowering patches. The two species differ in diet – the generalist diet including seasonally fruits and insects with nectar and pollen while the specialist diet is dominated by nectar and pollen yearlong – and in some morphological traits – the specialist being heavier and with proportionally longer rostrum than the generalist. These bats are found sympatrically within part of their range in the Neotropics. We habituated captive individuals to feed on artificial flower patches and we used infrared video recordings to monitor their ability to remember and avoid the spatial location of flowers they emptied in previous visits in the course of 15-min foraging sequences. Experiments revealed that both species rely on SWM as their foraging success attained significantly greater values than random expectations. However, the nectar specialist L. yerbabuenae was significantly more efficient at extracting nectar (+28% in foraging success), and sustained longer foraging bouts (+27% in length of efficient foraging sequences) than the generalist G. soricina. These contrasting SWM performances are discussed in relation to diet specialization and other life history traits

    Sleeping-tree fidelity of the spider monkey shapes community-level seed-rain patterns in continuous and fragmented rain forests

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    Repeated use of sleeping trees (STs) by frugivores promotes the deposition and aggregation of copious amounts of seed, thus having key implications for seed dispersal and forest regeneration. Seed-rain patterns produced by this behaviour likely depend on the frequency of use of these sites, yet this hypothesis has been poorly tested. We evaluated community-level seed-rain patterns produced by the spider monkey (Ateles geoffroyi) over 13 mo in latrines located beneath 60 STs in the Lacandona rain forest, Mexico. Because this primate is increasingly ‘forced’ to inhabit fragmented landscapes, we tested whether sleeping-tree fidelity (STF) differed among sites and between continuous and fragmented forests. We also tested whether seed-rain patterns were associated with STF within each site and forest type. STF was highly variable among STs (average = 7 mo, range = 1–12 mo), but did not differ among study sites or forest types. STF was positively associated with seed abundance, species diversity and species turnover. Nevertheless, STF tended to be negatively related to seed community evenness. These results are likely due to the most frequently used STs being in areas with greater food density. Our results demonstrate that site fidelity shapes community-level seed-rain patterns and thus has key ecological implications

    Monitoreo de procesos de ecológicos del Bosque Seco Tropical: Aplicaciones de sensores remotos para estimaciones a nivel de paisaje y el cambio global

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    Proyecto de Investigación. y extensión (Código VIE: 5402-1401-1012) Instituto Tecnológico de Costa Rica. Vicerrectoría de Investigación y Extensión (VIE). Escuela de Ingeniería Forestal; Alberta University, Canadá; University of Wisconsin; University of Virginia; Universidad Nacional Autónoma de México; Instituto Venezolano de Investigaciones Científicas; Agencia de Medio Ambiente. Cuba; Universidad Estatal de Belo Horizonte. Brasil; Universidad de Montes Claros. Brasil; Universidad de Pernambuco. Brasil; Universidad Estatal de Río de Janeiro. Brasil, 2014Este proyecto se encadenó al proyecto ya concluido "Dimensiones humanas, ecológicas y biofísicas de los bosques secos tropicales (código VIE 5402-1401-9001)". Durante su ejecución fue posible dar continuidad al análisis de datos y preparación de publicaciones científicas y académicas pendientes como fenología, dinámica de hojarasca, tasas de crecimiento, mortalidad y reingreso en el bosque seco tropical. También el proyecto trabajo en la preparación de artículos que integran los resultados de tres países: México, Costa Rica y Brasil. Así mismo se continuó con las mediciones de campo de las parcelas y procesos ecológicos para crear una base de datos robusta, actualmente y después de 10 años, estas bases permiten modelar los efectos de cambios climáticos en el comportamiento de los procesos ecológicos de los bosques secos tropicales (Bst). El elemento novedoso de este proyecto fue la instalación de torres de fenología por medio de financiamiento externo y que miden sobre el dosel del bosques seco tropical los cambios temporales de la radiación de onda corta y onda larga, tanto de entrada como de salida. Los cambios en la reflectancia de las hojas se relacionan tanto con el ángulo del sol (que podemos corregir automáticamente) como con la biomasa de hojas. Las torres permiten la colección de datos de campo a cada 15 minutos y estos datos se pueden calibrar con los índices de reflectancia de varios sensores espaciales. Una buena calibración para los diferentes tipos de bosques secos tropicales (las torres operan en Brasil, México y Costa Rica) puede permitir hacer simulaciones del efecto del cambio climático en la productividad de los bosques, su impacto en el ciclo del agua y por ende en las capacidades de fijar carbono. Además, el proyecto fue capaz de instalar una torre con equipo altamente especializado que permite determinar los flujos de CO2 y de vapor de agua del bosque seco tropical mediante la técnica de Covarianza de Flujos Turbulentos. Asociada a esta torre de 22 metros se estableció una parcela de una hectárea que permite caracterizar la huella de CO2 del ecosistema de forma más precisa. Esta hectárea permitirá mejorar la clasificación de imágenes satelitales y aéreas, así como también facilitara el uso de sensores remotos y otras técnicas de teledetección. Desde la perspectiva de los recursos naturales, se aplicó un protocolo comprensivo y estandarizado para reconocer y comparar las clasificaciones espaciales de los Bst, la estructura y composición florística de sus etapas sucesionales, dinámica de la hojarasca, fenología y tasas de crecimiento. Desde la perspectiva de las ciencias sociales, el trabajo que se realizó fue innovador dado que se crearon vínculos con el gobierno, los científicos y las comunidades. Se estudió las interacciones de las comunidades vecinas con los Bst, así como los factores socioeconómicos, políticos y legales que controlan su conservación y manejo. El proyecto fue capaz de generar la siguiente producción académica y científica: 9 artículos indexados, 2 artículos en español, 5 capítulos en libros en inglés, 1 capitulo en un enciclopedia, 20 ponencias en evento nacional, 6 ponencias en eventos internacionales, 10 artículos en borrador, 5 Tesis de pregrado y 2 Tesis de Doctorado. En medios de comunicación, el proyecto decidió ser más austero debido al alto valor de los equipos instalados en el Parque Nacional Santa Rosa para así no llamar la atención para provocar los robos o daños, sin embargo fue posible generar 7 publicaciones en medios impresos/Web y una intervención en radio nacional. En cuanto a la participación de talleres de incidencia política fueron organizados 3 talleres con decisores sobre el estado de los bosques secos en Costa Rica y sobre el potencial de trabajo conjunto entre organizaciones y el proyecto de investigación. Además se organizó una sesión de Simposio en el Congreso indexado de la ATBC y la OET en el año 2013. Adicionalmente se participó en otros 5 talleres organizados por otras instituciones. En total el proyecto recibió y entrenó a 29 estudiantes, de los cuales 9 fueron extranjeros y 20 del TEC, los cuales trabajaron como asistentes de laboratorio y campo entrenándose en el uso de instrumentos, montaje y medición de diseños experimentales, colección y procesamiento de datos y muestras. Actualmente se cuenta con una base de datos de crecimiento de 10 años, así como 4 años de datos de torres de fenología y 1 año y 3 meses de datos de flujos de carbono y vapor de agua, los cuales continuaran siendo analizados en la siguiente etapa del proyecto (código VIE 5402-1401-1028).Instituto Tecnológico de Costa Rica

    Tough Talks COVID-19 Digital Health Intervention for Vaccine Hesitancy Among Black Young Adults: Protocol for a Hybrid Type 1 Effectiveness Implementation Randomized Controlled Trial

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    Background Interventions for increasing the uptake of COVID-19 vaccination among Black young adults are central to ending the pandemic. Black young adults experience harms from structural forces, such as racism and stigma, that reduce receptivity to traditional public health messaging due to skepticism and distrust. As such, Black young adults continue to represent a priority population on which to focus efforts for promoting COVID-19 vaccine uptake. Objective In aims 1 and 2, the Tough Talks digital health intervention for HIV disclosure will be adapted to address COVID-19 vaccine hesitancy and tailored to the experiences of Black young adults in the southern United States (Tough Talks for COVID-19). In aim 3, the newly adapted Tough Talks for COVID-19 digital health intervention will be tested across the following three southern states: Alabama, Georgia, and North Carolina. Methods Our innovative digital health intervention study will include qualitative and quantitative assessments. A unique combination of methodological techniques, including web-based surveys, choose-your-own-adventures, digital storytelling, user acceptability testing, and community-based participatory approaches, will culminate in a 2-arm hybrid type 1 effectiveness implementation randomized controlled trial, wherein participants will be randomized to the Tough Talks for COVID-19 intervention arm or a standard-of-care control condition (N=360). Logistic regression will be used to determine the effect of the treatment arm on the probability of vaccination uptake (primary COVID-19 vaccine series or recommended boosters). Concurrently, the inner and outer contexts of implementation will be ascertained and catalogued to inform future scale-up. Florida State University’s institutional review board approved the study (STUDY00003617). Results Our study was funded at the end of April 2021. Aim 1 data collection concluded in early 2022. The entire study is expected to conclude in January 2025. Conclusions If effective, our digital health intervention will be poised for broad, rapid dissemination to reduce COVID-19 mortality among unvaccinated Black young adults in the southern United States. Our findings will have the potential to inform efforts that seek to address medical mistrust through participatory approaches. The lessons learned from the conduct of our study could be instrumental in improving health care engagement among Black young adults for several critical areas that disproportionately harm this community, such as tobacco control and diabetes prevention. Trial Registration ClinicalTrials.gov NCT05490329; https://clinicaltrials.gov/ct2/show/NCT05490329 International Registered Report Identifier (IRRID) DERR1-10.2196/4124

    Efecto de la perturbación del bosque en la tasa de visitas de murciélagos polinizadores y sus consecuencias sobre el éxito reproductivo y sistema de apareamiento en árboles de la familia Bombacaceae.

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    La fragmentación y la perturbación del bosque pueden tener efectos deletéreos sobre el éxito reproductivo y el sistema de apareamiento de los árboles tropicales, además de modificar el compartimiento de sus polinizadores. Los objetivos de este capítulo son: (1) evaluar el efecto de la perturbación del bosque sobre la tasa de visita de los murciélagos a cuatro especies de árboles de Bombacaceas; (2) comparar el éxito reproductivo entre árboles en áreas perturbadas y en bosques continuos; (3) determinar las consecuencias de un cambio en la tasa de visitas de los polinizadores sobre el éxito reproductivo de los árboles; y (4) documentar cómo los patrones de visita de los polinizadores pueden afectar el sistema de apareamiento de las plantas que polinizan. Se estudiaron cuatro especies de árboles de la familia Bombacaceae en los bosques tropicales de Jalisco, México, y en las regiones de Guanacaste y la Península de Osa, en Costa Rica. Los murciélagos nectarívoros fueron los únicos polinizadores efectivos para estas cuatro especies. Las flores de Ceiba grandiflora en el bosque recibieron más visitas por parte de Glossophaga soricina; no se observaron diferencias en el número de visitas por parte de Leptonycteris curasoae y Musonycteris harrisoni solo visitó flores dentro del bosque. Ceiba aesculifolia presentó una mayor tasa de visitas en los sitios perturbados, tanto por G.. soricina como por L. curasoae. Ceiba pentandra, en Chamela, no presentó diferencias en la tasa de visitas de G. soricina entre áreas perturbadas y bosque continuo, pero L. curasoae visitó una mayor cantidad de flores en bosque continuo. En Guanacaste, C. pentandra recibió más visitas de Phyllostomus discolor que de G presentó una mayor producción de flores en fragmentos y no hubo diferencias en la proporción de frutos por flor (fruto/flor). Ceiba grandiflora no presentó diferencias en la producción de flores, pero la razón fruto/flor fue mayor en el bosque. Pachira quinata presentó un patrón similar a C. aesculifolia en cuanto a la producción de flores, pero la razón fruto/flor fue mayor en los árboles de bosque continuo. Estas cuatro especies de Bombacaceae son predominantemente autoincompatibles. Los niveles de exocruzamiento fueron independientes del tipo de hábitat para C. aesculifolia, C. grandiflora y C. pentandra en Guanacaste; sin embargo, los árboles C. pentandra, en la Península de Osa, mostraron un sistema de apareamiento mixto. Los efectos de la perturbación del bosque sobre la polinización por murciélagos, la reproducción de plantas y sus patrones de apareamiento varían según la especie de Bombacaceae y su historia de vida.Forest fragmentation and disturbance can have negative effects on the reproductive success and mating systems of tropical trees, in addition to modifying the behavior of the pollinators that pollinate them. The objectives of this study are: (1) to evaluate the effect of forest disturbance on bat pollinator activity for four bombacaceous species; (2) to compare reproductive success between trees found in disturbed habitats and continuous forest; (3) to determine the consequences of a change in bat pollinator activity on plant reproductive success; and (4) to document how bat pollinator activity may affect breeding systems in the plants they pollinate. Four species from the Bombacaceae family were studied in the tropical forests of Jalisco, Mexico, and in the areas of Guanacaste and Peninsula de Osa, in Costa Rica. Nectarivorous bats were the only effective pollinators observed for these four species. Flowers from Ceiba grandiflora in the forest received more visits from Glossophaga soricina. No differences were observed for Leptonycteris curasoae and Musonycteris harrisoni was only observed visiting flowers in the forest. Flowers from C. aesculifolia in fragmented habitats received more visits from both G. soricina and L. curasoae. For C. pentandra in Chamela no differences in visits were observed for G. soricina between disturbed areas and continuous forest, but L. curasoae visited more flowers in continuous forest. In Guanacaste, C. pentandra received more visits from Phyllostoumus discolor than G. soricina, and in Osa no bat visits were observed. Ceiba aesculifolia produced more flowers in disturbed areas but no differences were observed for fruit set. Ceiba grandiflora showed no differences in flower production but fruit set was greater in the forest. Similar to C. grandiflora, Pachira quinata showed no differences in flower production, however, greater fruit set was observed in continuous forest. These four bombacaceous species are predominantly self-incompatible. Out-crossing rates were independent of habitat for C. aesculifolia, C. grandiflora, and C. pentandra en Guanacaste; however, C. pentandra trees from the Osa Peninsula showed a mixed breeding system. Our results show that the effects of forest disturbance on bat pollination, plant reproductive success and breeding system varied depending on the bombacaceous species and its life history characteristics.UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí

    Using narratives to inform the development of a digital health intervention related to COVID-19 vaccination in Black young adults in Georgia, North Carolina and Alabama

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    Interactive stories are a relatively newer form of storytelling with great potential to correct misinformation while increasing self-efficacy, which is crucial to vaccine acceptance. To address COVID-19 vaccine hesitancy and medical mistrust in young Black adults (BYA), we sought to adapt a pre-existing application (“app”; Tough Talks) designed to address HIV disclosure decision-making through choose-your-own adventure (CYOA) narratives and other activities. The adapted app (Tough Talks – COVID) uses a similar approach to situate COVID-19 vaccination decision-making within social contexts and to encourage greater deliberation about decisions. To inform content for the CYOA narratives, we conducted an online survey that was used to elicit the behavioral, cognitive, and environmental determinants influencing COVID-19 vaccine hesitancy among 150 BYA (ages 18–29) in Georgia, Alabama, and North Carolina. The survey included scenario questions that were developed with input from a youth advisory board to understand responses to peer and family influences. In two scenarios that involved discussions with family and friends about vaccination status, most respondents chose to be honest about their vaccination status. However, vaccinated individuals perceived more social pressure and stigma about not being vaccinated than unvaccinated respondents who were not as motivated by social pressure. Personal choice/agency in the face of perceived vaccine risks was a more common theme for unvaccinated respondents. Results suggest that relying on changing social norms alone may not impact barriers to vaccination in unvaccinated young adults without also addressing other barriers to vaccination such as concerns about autonomy and vaccine safety. Based on these findings, CYOA narratives in the app were adapted to include discussions with family and friends but also to touch on themes of personal choice as well as other topics that influence behaviors besides norms such as safety, side effects, and risk of COVID-19 in an evolving pandemic
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