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Background Rapid improvements in inexpensive, low-power, movement and environmental sensors have sparked a revolution in animal behavior research by enabling the creation of data loggers (henceforth, tags) that can capture fine-grained behavioral data over many months. Nevertheless, development of tags that are suitable for use with small species, for example, birds under 25 g, remains challenging because of the extreme mass (under 1$$\textrm{g}$$ g ) and power (average current under 1$$\upmu$$ μ A) constraints. These constraints dictate that a tag should carry exactly the sensors required for a given experiment and the data collection protocol should be specialized to the experiment. Furthermore, it can be extremely challenging to design hardware and software to achieve the energy efficiency required for long tag life. Results We present an activity monitor, BitTag, that can continuously collect activity data for 4–12 months at 0.5–0.8$$\textrm{g}$$ g , depending upon battery choice, and which has been used to collect more than 500,000 h of data in a variety of experiments. The BitTag architecture provides a general platform to support the development and deployment of custom sub-$$\textrm{g}$$ g tags. This platform consists of a flexible tag architecture, software for both tags and host computers, and hardware to provide the host/tag interface necessary for preparing tags for “flight” and for accessing tag data “post-flight”. We demonstrate how the BitTag platform can be extended to quickly develop novel tags with other sensors while satisfying the 1g/1$$\upmu$$ μ A mass and power requirements through the design of a novel barometric pressure sensing tag that can collect pressure and temperature data every 60$$\textrm{s}$$ s for a year with mass under 0.6$$\textrm{g}$$ g .

The twenty-first century has witnessed an explosion in research on animal migration, in large part due to a technological revolution in tracking and remote-sensing technologies, along with advances in genomics and integrative biology. We now have access to unprecedented amounts of data on when, where, and how animals migrate across various continents and oceans. Among the important advancements, recent studies have uncovered a surprising level of variation in migratory trajectories at the species and population levels with implications for both speciation and the conservation of migratory populations. At the organismal level, studies linking molecular and physiological mechanisms to traits that support migration have revealed a remarkable amount of seasonal flexibility in many migratory animals. Advancements in the theory for why animals migrate have resulted in promising new directions for empirical studies. We provide an overview of the current state of knowledge and promising future avenues of study.

American robins and dark-eyed juncos migrate across North America and have been found to be competent hosts for some bacterial and viral pathogens, but their contributions to arthropod-borne diseases more broadly remain poorly characterized. Here, we sampled robins and juncos in multiple sites across North America for arthropod-borne bacterial pathogens of public health significance. We identified two novel

Made available in DSpace on 2021-06-25T12:33:18Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-11-01 SELVA Society for the Study of Evolution American Ornithology Society Graduate Research Award Provost's Graduate Research Award from the University of Illinois at Chicago Field Museum's H. B. Conover Fund Society of Integrative and Comparative Biology Field Museum Armour Graduate Student Fellowship Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET-Argentina) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) University of Buenos Aires Sonations are sounds that animals produce with structures other than the vocal apparatus for communication. In birds, many sonations are usually produced with modified flight feathers through diverse kinematic mechanisms. For instance, aeroelastic fluttering of feathers produces tonal sound when airflow exceeds a threshold velocity and induces flight feathers to oscillate at a constant frequency. The Fork-tailed flycatcher (Tyrannus savana) is a Neotropical bird with both migratory and year-round resident subspecies that differ in the shape of the outer primary feathers of their wings. By integrating behavioral observations, audio recordings, and high-speed videos, we find that male Fork-tailed flycatchers produce sonations with their outer primary feathers P8-10, and possibly P7. These sounds are produced during different behavioral contexts including: the pre-dawn display, intraspecific territorial disputes, when attacking potential nest predators, and when escaping. By placing feathers in a wind tunnel, we elicited flutter at frequencies that matched the acoustic signature of sounds recorded in the wild, indicating that the kinematic mechanism responsible for sound production is aeroelastic flutter. Video of wild birds indicated that sonations were produced during the downstroke. Finally, the feathers of migratory (T.s.savana) and year-round resident (T.s.monachus) Fork-tailed flycatchers flutter in feather locations that differ in shape between the subspecies, and these shape differences between the subspecies result in sounds produced at different frequencies. Univ Illinois, Dept Biol Sci, 845 West Taylor St,MC066, Chicago, IL 60607 USA SELVA Invest Conservac Neotrop, Diagonal 42a 20-37, Bogota, Colombia Field Museum Nat Hist, Negaunee Integrat Res Ctr, 1400 South Lake Shore Dr, Chicago, IL 60605 USA Univ Buenos Aires, Dept Ecol Genet & Evoluc, Fac Ciencias Exactas & Nat, Inst IEGEBA CONICET UBA, Ciudad Univ,C1428EGA, RA-2160 Buenos Aires, DF, Argentina Univ Estadual Paulista, Inst Biociencias, Dept Zool, Ave 24a,1515, Rio Claro, SP, Brazil Univ Calif Riverside, Dept Evolut Ecol & Organismal Biol, Riverside, CA 92521 USA Univ Estadual Paulista, Inst Biociencias, Dept Zool, Ave 24a,1515, Rio Claro, SP, Brazil FAPESP: 2012/17225-2

Made available in DSpace on 2022-04-28T17:21:05Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-10-21 Indiana University's Prepared for Environmental Change Grand Challenge Initiative Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) James S. McDonnell Foundation Morphology is closely linked to locomotion and diet in animals. In animals that undertake long-distance migrations, limb morphology is under selection to maximize mobility and minimize energy expenditure. Migratory behaviours also interact with diet, such that migratory animals tend to be dietary generalists, whereas sedentary taxa tend to be dietary specialists. Despite a hypothesized link between migration status and morphology, phylogenetic comparative studies have yielded conflicting findings. We tested for evolutionary associations between migratory status and limb and bill morphology across kingbirds, a pan-American genus of birds with migratory, partially migratory and sedentary taxa. Migratory kingbirds had longer wings, in agreement with expectations that selection favours improved aerodynamics for long-distance migration. We also found an association between migratory status and bill shape, such that more migratory taxa had wider, deeper and shorter bills compared to sedentary taxa. However, there was no difference in intraspecific morphological variation among migrants, partial migrants and residents, suggesting that dietary specialization has evolved independently of migration strategy. The evolutionary links between migration, diet and morphology in kingbirds uncovered here further strengthen ecomorphological associations that underlie long-distance seasonal movements in animals. Tulane Univ, Dept Ecol & Evolutionary Biol, New Orleans, LA 70118 USA Louisiana State Univ, Museum Nat Sci, Baton Rouge, LA 70803 USA Univ Estadual Paulista, Dept Biodiversidade, Av 24a 1515, Rio Claro, Brazil Indiana Univ, Environm Resilience Inst, 717 E 8th St, Bloomington, IN 47408 USA Univ Estadual Paulista, Dept Biodiversidade, Av 24a 1515, Rio Claro, Brazil FAPESP: 2012/17225-2

South America is home to the highest diversity of birds on the planet, yet we still understand relatively little about their seasonal movements, or even which species are migratory. During two consecutive years, we used satellite transmitters to study the movement ecology of 10 individual Snail Kites (Rostrhamus sociabilis) captured in southern Brazil. We detected highly variable movement patterns among Snail Kites, with some migrating between two well-defined sites, migrating up to 4000 km to the mouth of the Amazon River. Others exhibited nomadic/facultative movements, moving different distances and to different sites between seasons and years. Overall, Snail Kites spent most of the migration period at stopover sites, moved at a higher speed, and used fewer stopovers in austral spring than in fall. These results provide the first evidence that Snail Kites in South America move across large distances, effectively connecting major watersheds, and suggest that individual Snail Kites are highly flexible in how they track resources over time and space. The complex movements and highly variable migratory behavior we detected among Snail Kites points to the need for more detailed research on the behavioral ecology and risks to survival across the annual cycle and broad range of this enigmatic and poorly understood species.

Objective Rhizoctonia solani is a soil-borne fungal pathogen of many important crop plants. In rice, R. solani causes sheath blight disease, which results in devastating grain yield and quality losses. Few methods are available to control this pathogen and classic single gene resistance mechanisms in rice plants have not been identified. We hypothesize that alternate means of control are available in the environment including free-living amoebae. Amoebae are soil-, water- and air-borne microorganisms that are predominantly heterotrophic. Many amoeba species are mycophagous, and several harm their prey using mechanisms other than phagocytosis. Here, we used light and scanning electron microscopy to survey the interactions of R. solani with four amoeba species, with the goal of identifying amoebae species with potential for biocontrol. Results We observed a wide range of responses during interactions of R. solani with four different free-living amoebae. Two Acanthamoeba species encyst in co-cultures with R. solani at higher rates than medium without R. solani. Vermamoeba vermiformis (formerly Hartmanella vermiformis) attach to R. solani mycelium and are associated with mycelial shriveling and perforations of fungal cell walls, indicating an antagonistic interaction. No phenotypic changes were observed in co-cultures of Dictyostelium discoideum and R. solani.

Little is known about the age at which many Neotropical bird species first attempt to breed. We evaluated the breeding condition of 515 adult and subadult males and females among four species of Turdus thrushes (T. nigriceps, T. chiguanco, T. amaurochalinus and T. rufiventris) in Tucumán, Argentina during three breeding seasons (2015 to 2018). We registered a total of 126 individuals with brood patches and cloacal protuberances, which accounted for 24.5% of thrushes in breeding condition that we sampled. Forty thrushes had a brood patch (31.7% of those in breeding condition), of which 11 were subadults (8.7%). Eighty-six thrushes (68.3%) had a swollen cloacal protuberance, 18 of which were subadults (14.3%). Only a few of the subadults in breeding condition built nests, incubated eggs or raised nestlings. Of 130 nests we found, only 3 belonged to a subadult thrush (in all cases, a subadult female with an adult social mate), one of which was successful. Further research on these patterns among various Neotropical bird species could lead to important insights into the life history strategies that characterize different populations, and how these ultimately affect their population dynamics.

1. Identifying the processes that determine avian migratory strategies in different environmental contexts is imperative to understanding the constraints to survival and reproduction faced by migratory birds across the planet. 2. We compared the spring migration strategies of Fork‐tailed Flycatchers (Tyrannus s. savana) that breed at south‐temperate latitudes (i.e., austral migrants) vs. tropi‐ cal latitudes (i.e., intratropical migrants) in South America. We hypothesized that austral migrant flycatchers are more time‐selected than intratropical migrants during spring migration. As such, we predicted that austral migrants, which mi‐ grate further than intratropical migrants, will migrate at a faster rate and that the rate of migration for austral migrants will be positively correlated with the onset of spring migration. 3. We attached light‐level geolocators to Fork‐tailed Flycatchers at two tropical breeding sites in Brazil and at two south‐temperate breeding sites in Argentina and tracked their movements until the following breeding season. 4. Of 286 geolocators that were deployed, 37 were recovered ~1 year later, of which 28 provided useable data. Rate of spring migration did not differ significantly between the two groups, and only at one site was there a significantly positive relationship between date of initiation of spring migration and arrival date. 5. This represents the first comparison of individual migratory strategies among con‐ specific passerines breeding at tropical vs. temperate latitudes and suggests that austral migrant Fork‐tailed Flycatchers in South America are not more time‐se‐ lected on spring migration than intratropical migrant conspecifics. Low sample sizes could have diminished our power to detect differences (e.g., between sexes), such that further research into the mechanisms underpinning migratory strategies in this poorly understood system is necessary., Facultad de Ciencias Naturales y Museo

Plant development, growth, and adaptation to stress are regulated by phytohormones, which can influence physiology even at low concentrations. Phytohormones are chemically grouped according to both structure and function as auxins, cytokinins, abscisic acid, jasmonates, salicylates, gibberellins, and brassinosteroids, among others. This chemical diversity and requirement for highly sensitive detection in complex matrices create unique challenges for comprehensive phytohormone analysis. Here, we present a robust and efficient quantitative UPLC-MS/MS assay for 17 phytohormones, including jasmonates, salicylates, abscisic acid, gibberellins, cytokinins, and auxins. Using this assay, 12 phytohormones were detected and quantified in sorghum plant tissue without the need for solid phase extraction (SPE) or liquid-liquid extraction. Variation of phytohormone profiles was explored in both root and leaf tissues between three genotypes, harvested at two different developmental time points. The results highlight the importance of tissue type, sampling time, and genetic factors when designing experiments that involve phytohormone analysis of sorghum. This research lays the groundwork for future studies, which can combine phytohormone profiling with other datasets such as transcriptome, soil microbiome, genome, and metabolome data, to provide important functional information about adaptation to stress and other environmental variables.

The Altillanura is a unique ecosystem within the Colombian Llanos, characterized by well-drained savannas and extensive riparian forests. The Altillanura harbors a rich assemblage of species, largely understudied and currently under threat by large-scale and unplanned agribusiness. Moreover, the number of public protected areas in the Colombian Llanos, particularly in the Altillanura, is insufficient to conserve the threatened habitats and species. Therefore, conservation efforts by private reserves are crucial for the protection of the region’s biodiversity. Here we present the first species list of the Tomogrande, a private nature reserve and scientific research field station in the municipality of Santa Rosalía, Vichada, Colombia. After ten years of ongoing research, we have recorded 299 species of plants, 189 species of birds, and 47 species of mammals. Compared to other private nature reserves in Vichada and the Tuparro National Park, the largest protected area in the region, Tomogrande makes a substantial contribution to the conservation of all three taxonomic groups. We advocate that better landscape planning and sustainable practices should become mandatory in the Altillanura to protect its biodiversity and the livelihoods of all stakeholders that inhabit this region.

Morphology is closely linked to locomotion and diet in animals. In animals that undertake long-distance migrations, limb-morphology is under selection to maximize mobility and minimize energy expenditure. Migratory behaviors also interact with diet, such that migratory animals tend to be dietary generalists, while sedentary taxa tend to be dietary specialists. Despite a hypothesized link between migration status and morphology, phylogenetic comparative studies have yielded conflicting findings. We tested for evolutionary associations between migratory status and limb and bill morphology across kingbirds, a pan-American genus of birds with migratory, partially migratory, and sedentary taxa. Migratory kingbirds had longer wings, in agreement with expectations if selection favors improved aerodynamics for long-distance migration. We also found an association between migratory status and bill shape, such that more migratory taxa had wider, deeper, and shorter bills compared to sedentary taxa. However, there was no difference in intraspecific morphological variation among migrants, partial migrants, and residents, suggesting that dietary specialization has evolved independently of migration strategy. The evolutionary links between migration, diet, and morphology in kingbirds uncovered here further strengthen ecomorphological associations that underlie long-distance seasonal movements in animals.

Made available in DSpace on 2021-06-25T10:23:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-03-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) For ages, the wide variety of colors, shapes, and behaviors of birds have attracted the attention of nature observers and professional ornithologists. Birdwatching represents an important source of data on many aspects of bird biology worldwide, particularly in Brazil, a highly biodiverse country. We reviewed the current state of citizen science with regard to Brazilian birdwatching by evaluating (a) where, (b) how much, and (c) what kind of data are collected by birdwatchers. To highlight the potential contribution of such data, we used citizen science data to evaluate the migration timing and habitat occupancy of four migratory bird species whose movements are still understudied. In addition, based on our assessment, we suggest new avenues for citizen science-based research on migratory bird ecology in Brazil. Finally, given that the urban ecology of numerous Brazilian birds is still poorly understood, we highlight how this can be remediated through the efforts of birdwatchers, given that 73% of the data is concentrated within or nearby large urban centers in southern and southeastern Brazil. We show that data generated by citizen scientists can be useful for a suite of studies, such as on habitat use and migration patterns of Brazilian birds. Therefore, citizen science is an important way to improve our knowledge about Brazilian birds and promote their conservation in an era of rapid change. Nevertheless, its impact in the long term will depend on improving the quality of the data and involvement of more birdwatchers. Graphical abstract: [Figure not available: see fulltext.] Departamento de Biodiversidade Laboratório de Ecologia Espacial e Conservação (LEEC) Instituto de Biociências Universidade Estadual Paulista (UNESP) BirdLife International/SAVE Brasil- Sociedade para Conservação das Aves do Brasil Environmental Resilience Institute Indiana University Departamento de Biodiversidade Laboratório de Ecologia Espacial e Conservação (LEEC) Instituto de Biociências Universidade Estadual Paulista (UNESP) CAPES: 001

Bird migration patterns are changing worldwide due to current global climate changes. Addressing the effects of such changes on the migration of birds in South America is particularly challenging because the details about how birds migrate within the Neotropics are generally not well understood. Here, we aim to infer the potential effects of future climate change on breeding and wintering areas of birds that migrate within South America by estimating the size and elevations of their future breeding and wintering areas. We used occurrence data from species distribution databases (VertNet and GBIF), published studies, and eBird for 3 thrush species (Turdidae; Turdus nigriceps, T. subalaris, and T. flavipes) that breed and winter in different regions of South America and built ecological niche models using ensemble forecasting approaches to infer current and future potential distributions throughout the breeding and wintering periods of each species. Our findings point to future shifts in wintering and breeding areas, mainly through elevational and longitudinal changes. Future breeding areas for T. nigriceps, which migrates along the Andes Mountains, will be displaced to the west, while breeding displacements to the east are expected for the other 2 species. An overall loss in the size of future wintering areas was also supported for 2 of the species, especially for T. subalaris, but an increase is anticipated for T. flavipes. Our results suggest that future climate change in South America will require that species shift their breeding and wintering areas to higher elevations in addition to changes in their latitudes and longitude. Our findings are the first to show how future climate change may affect migratory birds in South America throughout the year and suggest that even closely related migratory birds in South America will be affected in different ways, depending on the regions where they breed and overwinter.LAY SUMMARYBird ranges are changing worldwide due to current global climate changes.Bird migration is common in South America, with more than 200 species of Neotropical austral migrants, yet we still understand little about how these species are impacted by climate change.We modeled future breeding and winter distributions of 3 species of migratory thrushes in South America.Our results suggest that future wintering and breeding areas for migratory birds in South America will decrease, change in latitude and longitude, and shift to higher regions although patterns will likely vary by species.

Root pressure, also manifested as profusive sap flowing from cut stems, is a phenomenon in some species that has perplexed biologists for much of the last century. It is associated with increased crop production under drought, but its function and regulation remain largely unknown. In this study, we investigated the initiation, mechanisms, and possible adaptive function of root pressure in six genotypes of Sorghum bicolor during a drought experiment in the greenhouse. We observed that root pressure was induced in plants exposed to drought followed by re-watering but possibly inhibited by 100% re-watering in some genotypes. We found that root pressure in drought stressed and re-watered plants was associated with greater ratio of fine: coarse root length and shoot biomass production, indicating a possible role of root allocation in creating root pressure and adaptive benefit of root pressure for shoot biomass production. Using RNA-Seq, we identified gene transcripts that were up- and down-regulated in plants with root pressure expression, focusing on genes for aquaporins, membrane transporters, and ATPases that could regulate inter- and intra-cellular transport of water and ions to generate positive xylem pressure in root tissue.

Although the migration ecology of birds breeding in the Neotropics is still poorly studied relative to that of their counterparts breeding at north-temperate latitudes, studies conducted over the last 2 decades have revealed that migration in the Neotropics is much more common and diverse than previously thought. These studies have identified dozens of species that migrate latitudinally within South America, altitudinally within various mountain ranges, to and between Caribbean islands, and longitudinally across diverse ecosystems such as the Amazon rainforest. Advances in miniaturized tracking technologies, enormous citizen science databases, and powerful analytical approaches provide an unprecedented ability to detect and evaluate temporally and spatially fine-scale patterns, greatly facilitating the study of migratory patterns across tropical regions. We argue that a renewed effort in research on short- and long-distance bird migration within the Neotropics will allow (1) comparative studies that identify the emergent properties of migratory behavior, (2) identification of the convergent or unique mechanistic drivers of migration across diverse ecological settings, (3) formulation of effective conservation and management plans for migratory Neotropical birds, and (4) predictions about how migratory birds will respond to large-scale climatic changes within the Neotropics. Here, we review the current state of knowledge on Neotropical bird migration, with a focus on South America. We specifically examine similarities and differences in the observed migratory patterns of birds that breed in the Nearctic compared to the Neotropics and highlight key future research questions.

Se piensa que los cambios estacionales de los recursos controlan el momento de la migración anual de los animales; sin embargo, es poco lo que entendemos actualmente sobre cuáles son las señales ambientales o los recursos que las diferentes especies de aves migratorias siguen a lo largo del planeta. Entender cuáles son las señales ambientales o los recursos que las aves siguen en múltiples sistemas migratorios es un prerrequisito para desarrollar planes de conservación generalizados para las aves migratorias en un ambiente global cambiante. En el Nuevo Mundo, las diferencias climáticas que viven las especies de aves migratorias neártico-neotropicales (MNN; i.e., se reproducen en América del Norte y pasan el período no reproductivo en el Neotrópico) y las migratorias australes del neotrópico (MAN; i.e., se reproducen y pasan el período no reproductivo de modo completo en América del Sur) sugieren que sus estrategias migratorias pueden estar moldeadas por las mismas presiones de selección. Usamos datos recopilados a partir de individuos provistos de geo-localizadores de nivel de luz para construir modelos de distribución de especies (MDEs) y así evaluar qué factores ambientales controlan las estrategias migratorias de las especies en cada sistema. Para hacer esto, evaluamos si la temperatura, la precipitación y la productividad primaria (NDVI) estuvieron relacionadas con las distribuciones estacionales de las especies MNN (Tyrannus tyrannus) y MAN (T. savana). Las ubicaciones de ambas especies estuvieron positivamente correlacionadas con una alta precipitación durante sus estaciones no reproductivas. Las ubicaciones de T. tyrannus estuvieron positivamente correlacionadas con la NDVI y la temperatura durante la estación reproductiva y con las migraciones pre- and post-reproductivas. Las ubicaciones de T. savana estuvieron positivamente correlacionadas con la temperatura y la precipitación durante ambas migraciones, pero solo con la temperatura durante la estación reproductiva. El valor de extender las aplicaciones de los datos de geolocalización, como en los MDEs, queda en evidencia por el hallazgo de que la precipitación fue un predictor tan importante de las distribuciones no reproductivas de ambos tipos de migración, que no está claro cómo el cambio climático global afectará los ciclos húmedos-secos en los trópicos. Predictable seasonal changes in resources are thought to drive the timing of annual animal migrations; however, we currently understand little about which environmental cues or resources are tracked by different migratory bird species across the planet. Understanding which environmental cues or resources birds track in multiple migratory systems is a prerequisite to developing generalizable conservation plans for migratory birds in a changing global environment. Within the New World, climatic differences experienced by Nearctic-Neotropical migratory (NNM; i.e. breed in North America and spend the nonbreeding period in the Neotropics) and Neotropical austral migratory (NAM; i.e. breed and spend the nonbreeding period wholly within South America) bird species suggest that their migratory strategies may be shaped by unique selective pressures. We used data gathered from individuals fitted with light-level geolocators to build species distribution models (SDMs) to test which environmental factors drive the migratory strategies of species in each system. To do so, we evaluated whether temperature, precipitation, and primary productivity (NDVI) were related to the seasonal distributions of an NNM (Eastern Kingbird [Tyrannus tyrannus]) and NAM species (Fork-tailed Flycatcher [T. savana]). Both Eastern Kingbird and Fork-tailed Flycatcher locations were positively correlated with high precipitation during their nonbreeding seasons. Eastern Kingbird locations were positively correlated with both NDVI and temperature during their breeding season and both pre- and post-breeding migrations. Fork-tailed Flycatcher locations were positively correlated with both temperature and precipitation during both migrations, but only temperature during the breeding season. The value of extending the application of geolocator data, such as in SDMs, is underscored by the finding that precipitation was such an important predictor of the nonbreeding distributions of both types of migrants, as it remains unclear how global climate change will affect wet-dry cycles in the tropics. Fil: MacPherson, Maggie P.. Tulane University; Estados Unidos. University of Missouri; Estados Unidos Fil: Jahn, Alex. Universidade Estadual Paulista Julio de Mesquita Filho; Brasil Fil: Murphy, Michael T.. Portland State University; Estados Unidos Fil: Kim, Daniel H.. Portland State University; Estados Unidos Fil: Cueto, Víctor. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Centro de Investigación Esquel de Montaña y Estepa Patagóica. Universidad Nacional de la Patagonia "San Juan Bosco". Facultad de Ciencias Naturales - Sede Esquel. Centro de Investigación Esquel de Montaña y Estepa Patagónica; Argentina Fil: Tuero, Diego Tomas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina Fil: Hill, Elliot D.. Tulane University; Estados Unidos

The Great Plains low-level jet (LLJ) is influential in the initiation and evolution of nocturnal convection through the northward advection of heat and moisture, as well as convergence in the region of the LLJ nose. However, accurate numerical model forecasts of LLJs remain a challenge, related to the performance of the planetary boundary layer (PBL) scheme in the stable boundary layer. Evaluated here using a series of LLJ cases from the Plains Elevated Convection at Night (PECAN) program are modifications to a commonly used local PBL scheme, Mellor–Yamada–Nakanishi–Niino (MYNN), available in the Weather Research and Forecasting (WRF) Model. WRF forecast mean absolute error (MAE) and bias are calculated relative to PECAN rawinsonde observations. The first MYNN modification invokes a new set of constants for the scheme closure equations that, in the vicinity of the LLJ, decreases forecast MAEs of wind speed, potential temperature, and specific humidity more than 19%. For comparison, the Yonsei University (YSU) scheme results in wind speed MAEs 22% lower but specific humidity MAEs 17% greater than in the original MYNN scheme. The second MYNN modification, which incorporates the effects of potential kinetic energy and uses a nonzero mixing length in stable conditions as dependent on bulk shear, reduces wind speed MAEs 66% for levels below the LLJ, but increases MAEs at higher levels. Finally, Rapid Refresh analyses, which are often used for forecast verification, are evaluated here and found to exhibit a relatively large average wind speed bias of 3 m s−1 in the region below the LLJ, but with relatively small potential temperature and specific humidity biases.

Wind ramps are relatively large changes in wind speed over a period of a few hours and present a challenge for electric utilities to balance power generation and load. Failures of boundary-layer parametrization schemes to represent physical processes limit the ability of numerical models to forecast wind ramps, especially in a stable boundary layer. Herein, the eight “closure parameters” of a widely used boundary-layer parameterization scheme are subject to sensitivity tests for a set of wind-ramp cases. A marked sensitivity of forecast wind speed to closure-parameter values is observed primarily for three parameters that influence in the closure equations the depth of turbulent mixing, dissipation, and the transfer of kinetic energy from the mean to the turbulent flow. Reducing the value of these parameters independently by 25% or by 50% reduces the overall average in forecast wind-speed errors by at least 24% for the first two parameters and increases average forecast error by at least 63% for the third parameter. Doubling any of these three parameters increases average forecast error by at least 67%. Such forecast sensitivity to closure parameter values provides motivation to explore alternative values in the context of a stable boundary layer.

The viability of wind-energy generation is dependent on highly accurate numerical wind forecasts, which are impeded by inaccuracies in model representation of boundary-layer processes. This study revisits the basic theory of the Mellor, Yamada, Nakanishi, and Niino (MYNN) planetary boundary-layer parametrization scheme, focusing on the onset of wind-ramp events related to nocturnal low-level jets. Modifications to the MYNN scheme include: (1) calculation of new closure parameters that determine the relative effects of turbulent energy production, dissipation, and redistribution; (2) enhanced mixing in the stable boundary layer when the mean wind speed exceeds a specified threshold; (3) explicit accounting of turbulent potential energy in the energy budget. A mesoscale model is used to generate short-term (24 h) wind forecasts for a set of 15 cases from both the U.S.A. and Germany. Results show that the new set of closure parameters provides a marked forecast improvement only when used in conjunction with the new mixing length formulation and only for cases that are originally under- or over-forecast (10 of the 15 cases). For these cases, the mean absolute error (MAE) of wind forecasts at turbine-hub height is reduced on average by 17%. A reduction in MAE values on average by 26% is realized for these same cases when accounting for the turbulent potential energy together with the new mixing length. This last method results in an average reduction by at least 13% in MAE values across all 15 cases.

Climate studies based on global climate models (GCMs) project a steady increase in annual average temperature and severe heat extremes in central North America during the mid-century and beyond. However, the agreement of observed trends with climate model trends varies substantially across the region. The present study focuses on two different locations: Des Moines, IA and Austin, TX. In Des Moines, annual extreme temperatures have not increased over the past three decades unlike the trend of regionally-downscaled GCM data for the Midwest, likely due to a &ldquo, warming hole&rdquo, over the area linked to agricultural factors. This warming hole effect is not evident for Austin over the same time period, where extreme temperatures have been higher than projected by regionally-downscaled climate (RDC) forecasts. In consideration of the deviation of such RDC extreme temperature forecasts from observations, this study statistically analyzes RDC data in conjunction with observational data to define for these two cities a 95% prediction interval of heat extreme values by 2040. The statistical model is constructed using a linear combination of RDC ensemble-member annual extreme temperature forecasts with regression coefficients for individual forecasts estimated by optimizing model results against observations over a 52-year training period.

Made available in DSpace on 2020-12-10T19:56:45Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-04-06 Proyecto Semilla de la Universidad de los Andes National Geographic Society National Science Foundation International Research Fellowship Gatorade Fund of the University of Florida Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICETArgentina) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) National Science Foundation, USA National Aeronautics and Space Administration (USA) Migratory animals move up to thousands of kilometers every year [1]. Losses of migration (i.e., migratory drop-offs) occur when individuals of a migratory species stop migrating and establish founder sedentary populations, a phenomenon documented in birds [2-5] and butterflies [6]. In theory, losses-and also gains-of migration might promote speciation if sedentary and migratory populations become reproductively isolated [7-9]. Because migratory and sedentary strategies involve alternative physiological, behavioral, and morphological traits [10-13], divergence along multiple axes of organismal function is expected to accompany switches in migratory behavior, potentially accelerating speciation. We present evidence of speciation driven by a migratory drop-off in the fork-tailed flycatcher (Tyrannus savana) resulting in reproductive isolation likely driven by changes in breeding schedules (allochronic speciation [13-15]) and geographic isolation of breeding grounds (allopatric speciation [16]). Phylogenetic analyses across New World flycatchers (Tyrannidae) showed that an association between speciation and drop-offs is also observable at a macroevolutionary scale. Loss of migration was significantly more frequent than its gain, and speciation rates of migratory and partially migratory lineages (i.e., species having both migratory and sedentary populations) exceeded those of sedentary lineages. Models of trait evolution indicated that partial migration is an intermediate step between migratory and sedentary states in this family. Given that partial migration is widespread across migratory animals (e.g., of all migratory birds, ca. 51% are partially migratory [5]), speciation via switches in migratory behavior might be an important yet overlooked mechanism of animal diversification. Univ Illinois, Dept Biol Sci, 845 West Taylor St,MC066, Chicago, IL 60607 USA Univ Andes, Dept Ciencias Biol, 1,18A-12, Bogota, Colombia Field Museum Nat Hist, 1400 South Lake Shore Dr, Chicago, IL 60605 USA SELVA Invest Conservac Neotrop, Diagonal 42A,20-37, Bogota, Colombia Univ Chicago, Dept Ecol & Evolut, 1101 East 57th St, Chicago, IL 60637 USA Univ Estadual Paulista, Inst Biociencias, Dept Zool, Ave 24A,1515, Rio Claro, SP, Brazil Univ Sao Paulo, Inst Biociencias, Dept Genet & Biol Evolut, Rua Matao,277 Butanta, BR-05508090 Sao Paulo, SP, Brazil Univ Buenos Aires, Dept Genet & Biol Evolut, Fac Ciencias Exactas & Nat, Inst IEGEBA,CONICET, Intendente Guiraldes 2160,C1428EGA, Buenos Aires, DF, Argentina Pontificia Univ Javeriana, Fac Ciencias, Dept Biol, Carrera 7,40-62, Bogota, Colombia Univ Estadual Paulista, Inst Biociencias, Dept Zool, Ave 24A,1515, Rio Claro, SP, Brazil National Geographic Society: 8444-08 National Geographic Society: 8953-11 National Science Foundation International Research Fellowship: IRFP-0965213 FAPESP: 2012/17225-2 FAPESP: 2013/19116-9 FAPESP: BIOTA 2013/50297-0 National Science Foundation, USA: DOB 1343578

Root exudation is an important plant process by which roots release small molecules into the rhizosphere that serve in overall plant functioning. Yet, there is a major gap in our knowledge in translating plant root exudation in artificial systems (i.e., hydroponics, sterile media) to crops, specifically for soils expected in field conditions. Sorghum (Sorghum bicolor L. Moench) root exudation was determined using both ultra-performance liquid chromatography and gas chromatography mass spectrometry-based non-targeted metabolomics to evaluate variation in exudate composition of two sorghum genotypes among three substrates (sand, clay, and soil). Above and belowground plant traits were measured to determine the interaction between sorghum genotype and belowground substrate. Plant growth and quantitative exudate composition were found to vary largely by substrate. Two types of changes to rhizosphere metabolites were observed: rhizosphere-enhanced metabolites (REMs) and rhizosphere-abated metabolites (RAMs). More REMs and RAMs were detected in sand and clay substrates compared to the soil substrate. This study demonstrates that belowground substrate influences the root exudate profile in sorghum, and that two sorghum genotypes exuded metabolites at different magnitudes. However, metabolite identification remains a major bottleneck in non-targeted metabolite profiling of the rhizosphere.

Made available in DSpace on 2022-04-28T19:04:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-06-01 Fork-tailed Flycatchers (Tyrannus s. savana) breed from central to southern South America from September to January, migrating to northern South America to spend the non-breeding season. However, little is known of the migratory routes, rate, and timing of migration of those that breed in Brazil. In 2013, we attached light-level geolocators to breeding Fork-tailed Flycatchers breeding in São Paulo State. Data for six male flycatchers recaptured in 2014 indicates that they exhibited two fall migration strategies. Some individuals migrated northwest to the wintering grounds (primarily Colombia, Venezuela and northern Brazil), while others first spent several weeks in southwestern Brazil before going to the wintering grounds. Mean fall migration rate was 69 km/day (±13.7) during 59 (±13.2) days. Some flycatchers moved during winter, using more than one winter area. Flycatchers initiated spring migration in July and migrated southeast to the breeding grounds at a mean rate of 129 km/day (±19.0) during 27 (±2.8) days. A detailed understanding of the annual cycle of South America's migratory birds is essential to evaluating theoretical questions, such as the evolution of their life history strategies, in addition to applied questions, such as explanations for changes in population size, or their role as disease vectors. Departamento de Zoologia Universidade Estadual Paulista, Av. 24A, 1515 Point Blue Conservation Science, 3820 Cypress Drive #11 Ecology and Evolutionary Biology Tulane University Departamento de Zoologia Universidade Estadual Paulista, Av. 24A, 1515

La comprensión del ciclo anual de las aves migratorias es fundamental para evaluar la evolución de las estrategias del ciclo vital y el desarrollo de estrategias efectivas de conservación. Sin embargo, todavía sabemos poco sobre el ciclo anual de las aves migratorias que se reproducen en zonas templadas del sur de Sudamérica. Determinamos el año de edad, el sexo, y la progresión y la intensidad de muda de plumas del cuerpo, las remeras y las rectrices en las Atrapamoscas Tijereta (Tyrannus s. savana) en los sitios de cría en el sur de Sudamérica y en sitios de invernada en el norte de Sudamérica. La muda de plumas del cuerpo y plumas de vuelo ocurrió principalmente durante el invierno. En el comienzo del invierno, una proporción similar de jóvenes y adultos mudaron las plumas remeras y rectrices, pero la intensidad de la muda de remeras (número de remeras en muda) fue mayor y la progresión de la muda de remeras primarias (media de remeras primarias en muda) fue más avanzado en adultos. A finales del invierno, la intensidad y la progresión de la muda de las remeras primaria no difirió entre los grupos de edad. No se encontraron diferencias entre machos y hembras, tampoco en la proporción de individuos en muda en invierno o en la intensidad o el progreso de la muda de remeras. Nuestros resultados sugieren que la subespecie nominal de Atrapamoscas Tijereta se somete a una muda completa cada año en las zonas de invernada, y representan la primera evaluación integral del calendario de muda de una atrapamosca migratoria del nuevo mundo que pasa la invernada en los trópicos. Teniendo en cuenta que la cría, la muda y la migración representan tres etapas claves en el ciclo anual de las aves migratorias, el conocimiento del calendario de estos eventos es un primer paso a la comprensión del intercambio de ventajas y desventajas que enfrentan las aves migratorias durante el año. Understanding the annual cycle of migratory birds is imperative for evaluating the evolution of life-history strategies and developing effective conservation strategies. Yet, we still know little about the annual cycle of migratory birds that breed at south-temperate latitudes of South America. We aged, sexed, and determined the progression and intensity of body, remige, and rectrix molt of migratory Fork-tailed Flycatchers (Tyrannus s. savana) at breeding sites in southern South America and at wintering sites in northern South America. Molt of both body and flight feathers occurred primarily during the winter. In early winter, a similar proportion of young and adult flycatchers molted remiges and rectrices, but remige molt intensity (number of remiges molting) was greater and primary molt progression (mean primary feather molting) more advanced in adults. In late winter, remige molt intensity and primary molt progression did not differ between age groups. We found no difference between males and females either in the proportion of individuals molting in winter or in the intensity or progress of remige molt. Our results suggest that the nominate subspecies of Fork-tailed Flycatcher undergoes one complete, annual molt on the wintering grounds, and represents the first comprehensive evaluation of molt timing of a migratory New World flycatcher that overwinters in the tropics. Given that breeding, molt, and migration represent three key events in the annual cycle of migratory birds, knowledge of the timing of these events is the first step toward understanding the possible tradeoffs migratory birds face throughout the year. Fil: Jahn, Alex. Universidade Estadual Paulista Julio de Mesquita Filho; Brasil Fil: Giraldo, José I.. Aves Internacionales; Colombia Fil: MacPherson, Maggie. University of Tulane; Estados Unidos Fil: Tuero, Diego Tomas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentina Fil: Sarasola, José Hernán. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentina Fil: Cereghetti, Joaquín. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Masson, Diego A.. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; Argentina Fil: Morales, Marvin V.. University of Florida; Estados Unidos

Made available in DSpace on 2020-12-12T01:15:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-05-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) A large body of evidence indicates that urbanization profoundly affects ecological communities, but the extent to which patterns are generalizable across regions, such as in the Neotropics, remains unclear. We examined responses of migratory and resident birds to human disturbance and habitat attributes in São Paulo, Brazil, a tropical megacity in South America. In 2017–2018, we surveyed birds across 31 landscapes distributed across the urban landscape and evaluated competing models that included five non-correlated variables explaining variation in species richness: ambient noise level, distance to water, tree cover, human population size, and impervious surface. We recorded 142 bird species, 128 of which were resident and 14 migratory. Richness of both resident and migratory birds declined with increasing noise level and distance to water, which best explained variation in bird communities among the sampled landscapes. Although resident and migratory birds presented similar response patterns to local and landscape attributes, noise level was the best predictor of migratory species occurrence, whereas distance to water best explained the occurrence of resident species. Our results suggest that, although tree cover is important to biodiversity in urbanized landscapes, proper management of urban water bodies and reduction of noise levels are also essential to maintaining avian diversity within tropical urban areas and suggest novel avenues for future research in tropical urban ecology. Instituto de Biociências Universidade Estadual Paulista (UNESP) Departamento de Ecologia Laboratório de Ecologia Espacial e Conservação (LEEC) Cornell Lab of Ornithology and Department of Natural Resources Cornell University Environmental Resilience Institute Indiana University, 717 E 8th St Instituto de Biociências Universidade Estadual Paulista (UNESP) Departamento de Ecologia Laboratório de Ecologia Espacial e Conservação (LEEC)

Made available in DSpace on 2018-12-11T16:54:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-08-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) A large body of research has shown how avian morphology is shaped by specific behavioral repertoires and life history traits. Yet, the majority of such research has been conducted on birds breeding at north-temperate latitudes. We tested the hypothesis that functional wing traits of Fork-tailed Flycatchers (Tyrannus savana), which migrate within South America, vary predictably between non-migratory and migratory flycatchers. Additionally, due to sex-specific differences in this species (e.g., males perform courtship displays), we explored sex-related variation in wing shape. We applied classic measures of wing shape (e.g., wing loading, length, aspect ratio, pointedness), as well as landmark-based morphometric analysis to describe the wing morphology of Fork-tailed Flycatchers from breeding populations across South America. We found that migratory flycatchers tend to have more pointed wings than non-migratory flycatchers. Additionally, we found that males have wings that are significantly longer, more pointed, with a higher aspect ratio and that are more swept than those of females, regardless of whether they migrate or not. Overall, our results suggest that wing shape of Fork-tailed Flycatchers is the result of a complex set of tradeoffs shaped by selective pressures exerted on both sexes (i.e., the need to forage on the wing, evade predators and migrate efficiently), as well as sex-specific behaviors (e.g., the need for males to execute acrobatic displays). Instituto de Biociências de Rio Claro Universidade Estadual Paulista (UNESP), Av. 24A, No. 1515 Smithsonian Conservation Biology Institute Migratory Bird Center, 3001 Connecticut Ave. NW Instituto de Biociências de Rio Claro Universidade Estadual Paulista (UNESP), Av. 24A, No. 1515 FAPESP: 2012/17225-2 FAPESP: 2013/19116-9

La estrategia de historia de vida de un organismo se compone de un conjunto de caracteres fisiológicos, comportamentales y ecológicos, los cuales varían tanto a nivel intra como inter-especifico de acuerdo a la presión selectiva que opera sobre los individuos. En aves, se han propuesto dos factores ecológicos principales para explicar la variación intra e inter-especifica en el crecimiento de los pichones: la predación de nidos y la disponibilidad de alimento. Las tasas de crecimiento individuales de los pichones tienen importantes consecuencias sobre el éxito reproductivo debido a que la velocidad del crecimiento influye en el posterior rendimiento reproductivo y en la supervivencia. En el presente trabajo, estudiamos la relación entre factores ecológicos (e.g. nivel de precipitaciones y tasa de predación), y los patrones de crecimiento de pichones de dos especies de Atrapamoscas del Nuevo Mundo (Tyrannidae) del género Tyrannus (la Tijereta, T. savana y la Tijereta rosada, T. forficatus) que se reproducen a latitudes temperadas del norte y del sur. Se puso a prueba la hipótesis que la tasa de crecimiento de los pichones está influenciada por la tasa de predación de nidos y predecimos que el crecimiento de los pichones sería más rápido en especies que experimentan altas tasas de predación. También, se puso a prueba la hipótesis que la tasa de crecimiento de los pichones está relacionada con los niveles de precipitaciones (estimador de la abundancia de alimento) y predecimos que la tasa de crecimiento de los pichones sería mayor en sitios con mayores niveles de precipitaciones. La tasa de crecimiento no estuvo asociada con la tasa de predación en ninguna de las especies estudiadas, pero su variación estuvo relacionada con los niveles de precipitaciones. La tasa de crecimiento de los pichones fue mayor durante los años húmedos para la Tijereta rosada que vive en latitudes temperadas del norte. La tasa de crecimiento entre especies fue similar durante los años húmedos. Estos resultados indican que, por lo menos en una escala de tiempo ecológica, las precipitaciones explican la variación en la tasa de crecimiento tanto intra como inter-especifica en mayor grado que la predación en estas especies de Tyrannus. Finalmente, la variación en la tasa de crecimiento observada entre años secos y húmedos indica una alta plasticidad fenotípica en la tasa de crecimiento en este grupo de aves insectívoras., An organism's life history strategy is made up of a suite of physiological, behavioral, and ecological traits, which vary at both the interspecific and intraspecific levels in accordance with selective pressures operating on individuals. For birds, 2 primary ecological factors have been proposed to explain intraspecific and interspecific variation in nestling growth: nest predation and food availability. Individual nestling growth rates have important consequences for overall fitness because growth speed could influence subsequent reproductive performance and survival. We studied the relationship between ecological factors (i.e. precipitation level and predation rate) and nestling growth patterns of 2 New World flycatcher species (Tyrannidae) of the genus Tyrannus (Fork-Tailed Flycatcher T. savana and Scissor-Tailed Flycatcher T. forficatus) breeding at south-And north-Temperate latitudes. We tested the hypothesis that nestling growth rates are driven by nest predation rates and predicted that nestling growth rates would be higher in species experiencing higher nest predation rates. We also tested the hypothesis that nestling growth rates are related to precipitation levels (a proxy for food abundance) and predicted that nestling growth rates would be higher at sites with higher precipitation levels. Growth rate was not associated with predation rate, but it varied with precipitation level, with faster nestling growth rates during wet years for the Scissor-Tailed Flycatcher living at north-Temperate latitudes. Among species, similar growth rates were found during wet years. These results indicate that, at least as proximate causes, precipitation explains intraspecific and interspecific growth rate variation in Tyrannus species to a larger degree than predation. Additionally, the variation in growth rate we observed between wet and dry years indicates a high level of plasticity in growth rate in this group of insectivorous birds., Facultad de Ciencias Naturales y Museo

Made available in DSpace on 2022-04-28T19:27:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-06-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fork-tailed Flycatchers (Tyrannus s. savana) breed from central to southern South America, then migrate to northern South America, where they undergo a winter molt. However, exactly when this winter molt begins is not known. Previous research showed that some Fork-tailed Flycatchers stopover for an extended period in Mato Grosso do Sul in late January/early February, during fall migration. We hypothesized that these flycatchers are suspending fall migration to initiate flight feather molt, as do congeners in North America. In February 2016, we located a roost of >100 migratory flycatchers in Mato Grosso do Sul state and captured two adults and two juveniles, one of which was an adult female that was symmetrically molting the first primary feather. This is the furthest south that this species has been found molting flight feathers and suggests that some Fork-tailed Flycatchers undertake fall molt-migration to Mato Grosso do Sul. Further research on the relationship between timing of molt and migration of this and other birds that migrate within South America will be essential to evaluate the evolution of their life history strategies, seasonal interactions, and limitations they face throughout the year. Departamento de Zoologia Universidade Estadual Paulista Departamento de Zoologia Universidade Federal do Paraná Smithsonian Conservation Biology Institute Migratory Bird Center National Zoological Park Departamento de Zoologia Universidade Estadual Paulista CAPES: 1459754 CAPES: 2012/17225-2