Exploiting virtual globes for ecology and conservation in the Digital Earth era

Letter.Peer Reviewe

Assessing species habitat using Google Street View: A case study of cliff-nesting vultures

The assessment of a species' habitat is a crucial issue in ecology and conservation. While the collection of habitat data has been boosted by the availability of remote sensing technologies, certain habitat types have yet to be collected through costly, on-ground surveys, limiting study over large areas. Cliffs are ecosystems that provide habitat for a rich biodiversity, especially raptors. Because of their principally vertical structure, however, cliffs are not easy to study by remote sensing technologies, posing a challenge for many researches and managers working with cliff-related biodiversity. We explore the feasibility of Google Street View, a freely available on-line tool, to remotely identify and assess the nesting habitat of two cliff-nesting vultures (the griffon vulture and the globally endangered Egyptian vulture) in northwestern Spain. Two main usefulness of Google Street View to ecologists and conservation biologists were evaluated: i) remotely identifying a species' potential habitat and ii) extracting fine-scale habitat information. Google Street View imagery covered 49% (1,907 km) of the roads of our study area (7,000 km2). The potential visibility covered by on-ground surveys was significantly greater (mean: 97.4%) than that of Google Street View (48.1%). However, incorporating Google Street View to the vulture's habitat survey would save, on average, 36% in time and 49.5% in funds with respect to the on-ground survey only. The ability of Google Street View to identify cliffs (overall accuracy = 100%) outperformed the classification maps derived from digital elevation models (DEMs) (62-95%). Nonetheless, high-performance DEM maps may be useful to compensate Google Street View coverage limitations. Through Google Street View we could examine 66% of the vultures' nesting-cliffs existing in the study area (n = 148): 64% from griffon vultures and 65% from Egyptian vultures. It also allowed us the extraction of fine-scale features of cliffs. This World Wide Web-based methodology may be a useful, complementary tool to remotely map and assess the potential habitat of cliff-dependent biodiversity over large geographic areas, saving survey-related costs.PMT was supported by a postdoctoral grant funded by Junta de Comunidades de Castilla-La Mancha and Fondo Social Europeo.Peer Reviewe

Nested species- rich networks of scavenging vertebrates support high levels of interspecific competition

et al.Disentangling the processes that shape the organization of ecological assemblages and its implications for species coexistence is one of the foremost challenges of ecology. Although insightful advances have recently related community composition and structure with species coexistence in mutualistic and antagonistic networks, little is known regarding other species assemblages, such as those of scavengers exploiting carrion. Here we studied seven assemblages of scavengers feeding on ungulate carcasses in mainland Spain. We used dynamical models to investigate if community composition, species richness and structure (nestedness) affect species coexistence at carcasses. Scavenging networks showed a nested pattern in sites where highly efficient, obligate scavengers (i.e., vultures) were present and a non- nested pattern everywhere else. Griffon Vulture ( Gyps fulvus ) and certain meso- facultative mammalian scavengers (i.e., red fox, Vulpes vulpes, and stone marten, Martes foina ) were the main species contributing to nestedness. Assemblages with vultures were also the richest ones in species. Nested species- rich assemblages with vulture presence were associated with high carcass consumption rates, indicating higher interspecific competition at the local scale. However, the proportion of species stopping the consumption of carrion (as derived from the competitive dynamic model) stabilized at high richness and nestedness levels. This suggests that high species richness and nestedness may characterize scavenging networks that are robust to high levels of interspecific competition for carrion. Some facilitative interactions driven by vultures and major facultative scavengers could be behind these observations. Our findings are relevant for understanding species' coexistence in highly competitive systems.E. Sebastián-González and P. R. Guimarães benefited from FAPESP Research Foundation grants numbers 2011/17968-2 and 2009/054422-8, respectively; E. Sebastián-González is currently funded under the NSF grant NSF Award #1345247, M. Moleón by a postdoctoral grant from the Spanish Ministry of Education (Plan Nacional de I+D+I 2008-2011), J. P. Gibert by an Other Fellowship and SBS Special Funds (U. of N.), and P. Mateo-Tomás by a postdoctoral grant of the Junta de Comunidades de Castilla- La Mancha and Fondo Social Europeo. The study was supported by the Spanish Ministry of Science and Innovation through projects 23/2007 ICTS- RBD, CGL2009-12753-C02-02, and CGL2012-40013-C02-02, FEDER funds, the Generalitat Valenciana through project ACOMP/2012/147, and the Junta de Andalucía through project RNM-1925.Peer Reviewe

Aplicación de los Sistemas de Información Geográficos (SIG) en el análisis de la bonificación por ubicación

Territorialmente Tucumán se encuentra entre las provincias más pequeñas de la República Argentina. Sin embargo, encontramos en toda su extensión distintas realidades respecto de la accesibilidad a los servicios básicos necesarios por parte de la población. Estas distintas realidades pueden traducirse en un potencial favorable o desfavorable para el desarrollo de cualquier actividad. En este contexto, el Sistema Educativo debe adaptarse a las distintas situaciones territoriales para poder cumplir con su misión. Por ello, una estrategia que se utiliza es la de equiparar desde lo económico la desigualdad que puede presentar la realidad territorial donde un docente desempeñará sus funciones. Es así que el Ministerio de Educación de la Provincia de Tucumán implemento el concepto de Bonificación por Ubicación, el cual adiciona un plus salarial a los docentes en función de la desfavorabilidad de la situación territorial del establecimiento donde realizaran sus labores. En este trabajo exploramos como la aplicación de un SIG puede colaborar en la mejora del estudio para la determinación de este adicional salarial.Sociedad Argentina de Informática e Investigación Operativ

Direct detection of pseudo-Nambu-Goldstone dark matter in a two Higgs doublet plus singlet extension of the SM

We calculate the leading radiative corrections to the dark-matter-nucleon scattering in the pseudo-Nambu-Goldstone dark matter model augmented with a second Higgs doublet (S2HDM). In this model, the cross sections for the scattering of the dark-matter on nuclei vanishes at tree-level in the limit of zero momentum-transfer due to a U(1) symmetry. However, this symmetry is softly broken in order to give a mass to the dark-matter particle. As a consequence, non-vanishing scattering cross sections arise at the loop level. We find that the current cross-section limits from dark-matter direct-detection experiments can hardly constrain the parameter space of the S2HDM. However, the loop-corrected predictions for the scattering cross sections can be well within the reach of future direct-detection experiments. As a consequence, future phenomenological analyses of the S2HDM should take into account cross-section predictions beyond tree-level and the experimental constraints from dark-matter direct-detection experiments.Comment: 27 pages, 9 figure

ANATRI 1.0: representation of dichotomous and polytomous item characteristic functions

El programa ANATRI permite estudiar varios modelos de Teoría de la Respuesta al Item para items dicotómicos y politómicos. Los modelos para items dicotómicos incluidos son los denominados como de 1, 2, 3 y 4 parámetros, en sus versiones normal y logística. Los modelos para items politómicos son el modelo de respuesta graduada, el modelo de crédito parcial y el modelo de respuesta nominal. El usuario selecciona el modelo y especifica los parámetros de uno o varios items. Mediante el programa se obtienen las curvas características de los items y, en su caso, las funciones de regresión asociadas a las diversas segmentaciones. Permite analizar en profundidad las propiedades particulares de los items, con lo que se facilita la didáctica de los diferentes modelosThe ANATRI program helps the user in studying dichotomous and polytomous Item Response Theory models. Normal and logistic versions for the 1-, 2-, 3- and 4-parameter models are included. Three polytomous models (Partial Credit, Nominal Response and Graded Response) are also available. The user chooses the model and specifies its parameters for one or more items. Items characteristic (or operating characteristic) curves are depicted. A deep analysis of just one item is also possible. This option allows a better understanding of peculiarities of each mode

Learning from the past to address the future. Environmental challenges of Spanish agriculture in the 21st century: a look from the legacy of Fernando González Bernáldez

Based on the pioneering reflections of González Bernáldez at the end of the 1980s on the environmental consequences of agricultural intensification and abandonment, we review the changes experienced by the Spanish agriculture up to the present in environmental issues, identifying some of the future challenges. First, we review the progressive integration of environmental and territorial aspects in the European Common Agricultural Policy (CAP), as well as Spain's response in terms of adoption and implementation of its main instruments: Conditionality on direct payments and Agri-environmental measures. The CAP reforms have not counteracted the effects of agricultural intensification, to which the severe negative trends observed in the main agri-environmental indicators, analyzed here for the period 1989-2020, can be related. The new governance model introduced by the CAP 2023-2027, focused on results, is expected to contribute decisively to the objectives of the "European Climate Law" and the "Farm to Fork" and "Biodiversity 2030" strategies; however, doubts persist about its transformative potential. Finally, we review the main contributions of Agroecology, Organic Agriculture, Sustainable Intensification and Ecological Intensification, which can help in the transition towards a more sustainable and resilient agriculture. The actions of the CAP aimed at producers must pursue the multifunctional redesign of the agroecosystems, through payments for environmental services that make them sufficiently attractive and profitable as González Bernáldez suggested three decades ag

Exploring the size of Andean condor foraging groups along an altitudinal and latitudinal gradient in the Tropical Andes: Ecological and conservation implications

Patterns of variation in the size of vulture foraging groups, and their ecological causes and consequences, remain little explored despite strong links with the carrion recycling service that this key functional group provides. We documented the group size-frequency pattern of Andean con dors Vultur gryphus gathered to feed on 42 equine carcasses experimentally placed in Bolivia, between 2012 and 2019, along an elevation range of 1,300–4,500 m asl. Based on the location (altitude and latitude) of the foraging groups, we examined the relationship between their size and species’ population parameters (size and trend), habitat conditions, and livestock carcass availability and predictability. Condors utilized a high frequency (93%) of carcasses forming groups that ranged from 1 to 80 individuals (mean = 25, median = 18) and shaped a “lazy-J curve” typical pattern of size-frequency distribution whereby few groups (5, 12%) were large (> 55 individuals) and most (21, 50%) were relatively small (<19 individuals). Group size related to altitude in that most larger groups formed at lower sites (below c. 3,000 m asl), likely following an altitudinal gradient whereby larger groups are more likely to form around larger carcasses (i.e., cattle), which are more likely to occur at lower elevations. Regardless of population size, group size could be an adaptive response of condors via local enhancement for improving individual scavenging efficiency. Many information gaps on this topic still exist, thus we provide a set of questions to address them, especially amidst the unrestricted impacts of human activities that condition vulture survival globallyThe fieldwork that allowed making the reported observations was funded by The Peregrine Fund’s Neotropical Science and Student Education Program, a British Ornithologists’ Union Small Ornithological Research Grant, a Neotropical Birding and Conservation (formerly known as Neotropical Bird Club) Conservation Award granted to D. Méndez in 2014, and two 2018 grants to D. Méndez, one from the Rufford Small Grants Foundation (24763-1) and another from the International Foundation for Science (I-1-D-6156-1

Optimal Paternalistic Savings Policies

Abstract We study optimal savings policies when there is a dual concern about undersaving for retirement and income inequality. Agents differ in present bias and earnings ability, both unobservable to a planner with paternalistic and redistributive motives. We characterize the solution to this two-dimensional screening problem and provide a decentralization using realistic policy instruments: mandatory savings at low incomes but a choice between subsidized savings vehicles at high incomes—resembling Social Security, 401(k), and IRA accounts in the US. Offering more savings choice at higher incomes facilitates redistribution. To solve large-scale versions of this problem numerically, we propose a general, computationally stable, and efficient active-set algorithm. Relative to the current US retirement system, we find significant welfare gains from increasing mandatory savings and limiting savings choice at low incomes

Optimal Paternalistic Savings Policies

Abstract We study optimal savings policies when there is a dual concern about undersaving for retirement and income inequality. Agents differ in present bias and earnings ability, both unobservable to a planner with paternalistic and redistributive motives. We characterize the solution to this two-dimensional screening problem and provide a decentralization using realistic policy instruments: mandatory savings at low incomes but a choice between subsidized savings vehicles at high incomes—resembling Social Security, 401(k), and IRA accounts in the US. Offering more savings choice at higher incomes facilitates redistribution. To solve large-scale versions of this problem numerically, we propose a general, computationally stable, and efficient active-set algorithm. Relative to the current US retirement system, we find significant welfare gains from increasing mandatory savings and limiting savings choice at low incomes